draft-ietf-manet-dymo-11.txt   draft-ietf-manet-dymo-12.txt 
Mobile Ad hoc Networks Working I. Chakeres Mobile Ad hoc Networks Working I. Chakeres
Group Motorola Group Motorola
Internet-Draft C. Perkins Internet-Draft C. Perkins
Intended status: Standards Track Nokia Intended status: Standards Track
Expires: May 21, 2008 November 18, 2007 Expires: August 10, 2008 February 7, 2008
Dynamic MANET On-demand (DYMO) Routing Dynamic MANET On-demand (DYMO) Routing
draft-ietf-manet-dymo-11 draft-ietf-manet-dymo-12
Status of this Memo Status of this Memo
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This Internet-Draft will expire on May 21, 2008. This Internet-Draft will expire on August 10, 2008.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
Abstract Abstract
The Dynamic MANET On-demand (DYMO) routing protocol is intended for The Dynamic MANET On-demand (DYMO) routing protocol is intended for
use by mobile modes in wireless, multihop networks. It offers use by mobile nodes in wireless, multihop networks. DYMO determines
adaptation to changing network topology and determines unicast routes unicast routes between DYMO routers within the network in an on-
between DYMO routers within the network in an on-demand fashion. demand fashion, offering improved convergence in dynamic topologies.
Table of Contents Table of Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Applicability Statement . . . . . . . . . . . . . . . . . . . 4 2. Applicability Statement . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Data Structures . . . . . . . . . . . . . . . . . . . . . . . 7 4. Data Structures . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. Route Table Entry . . . . . . . . . . . . . . . . . . . . 7 4.1. Route Table Entry . . . . . . . . . . . . . . . . . . . . 7
4.2. DYMO Messages . . . . . . . . . . . . . . . . . . . . . . 8 4.2. DYMO Messages . . . . . . . . . . . . . . . . . . . . . . 8
4.2.1. Generalized MANET Packet and Message Structure . . . . 8 4.2.1. Generalized Packet and Message Structure . . . . . . . 8
4.2.2. Routing Messages (RM) - RREQ & RREP . . . . . . . . . 9 4.2.2. Routing Messages (RM) - RREQ & RREP . . . . . . . . . 9
4.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 13 4.2.3. Route Error (RERR) . . . . . . . . . . . . . . . . . . 12
5. Detailed Operation . . . . . . . . . . . . . . . . . . . . . . 14 5. Detailed Operation . . . . . . . . . . . . . . . . . . . . . . 14
5.1. DYMO Sequence Numbers . . . . . . . . . . . . . . . . . . 14 5.1. DYMO Sequence Numbers . . . . . . . . . . . . . . . . . . 14
5.1.1. Maintaining A Node's Own Sequence Number . . . . . . . 15 5.1.1. Maintaining A Node's Own Sequence Number . . . . . . . 15
5.1.2. Numerical Operations on OwnSeqNum . . . . . . . . . . 15 5.1.2. Numerical Operations on OwnSeqNum . . . . . . . . . . 15
5.1.3. OwnSeqNum Rollover . . . . . . . . . . . . . . . . . . 15 5.1.3. OwnSeqNum Rollover . . . . . . . . . . . . . . . . . . 15
5.1.4. Actions After OwnSeqNum Loss . . . . . . . . . . . . . 15 5.1.4. Actions After OwnSeqNum Loss . . . . . . . . . . . . . 15
5.2. DYMO Routing Table Operations . . . . . . . . . . . . . . 15 5.2. DYMO Routing Table Operations . . . . . . . . . . . . . . 15
5.2.1. Judging Routing Information's Usefulness . . . . . . . 16 5.2.1. Judging Routing Information's Usefulness . . . . . . . 16
5.2.2. Creating or Updating a Route Table Entry with New 5.2.2. Creating or Updating a Route Table Entry with
Routing Information . . . . . . . . . . . . . . . . . 17 Received Superior Routing Information . . . . . . . . 17
5.2.3. Route Table Entry Timeouts . . . . . . . . . . . . . . 18 5.2.3. Route Table Entry Timeouts . . . . . . . . . . . . . . 18
5.3. Routing Messages . . . . . . . . . . . . . . . . . . . . . 19 5.3. Routing Messages . . . . . . . . . . . . . . . . . . . . . 19
5.3.1. RREQ Creation . . . . . . . . . . . . . . . . . . . . 19 5.3.1. RREQ Creation . . . . . . . . . . . . . . . . . . . . 19
5.3.2. RREP Creation . . . . . . . . . . . . . . . . . . . . 20 5.3.2. RREP Creation . . . . . . . . . . . . . . . . . . . . 20
5.3.3. Intermediate DYMO Router RREP Creation . . . . . . . . 21 5.3.3. Intermediate DYMO Router RREP Creation . . . . . . . . 20
5.3.4. RM Processing . . . . . . . . . . . . . . . . . . . . 21 5.3.4. RM Processing . . . . . . . . . . . . . . . . . . . . 21
5.3.5. Adding Additional Routing Information to a RM . . . . 24 5.3.5. Adding Additional Routing Information to a RM . . . . 24
5.4. Route Discovery . . . . . . . . . . . . . . . . . . . . . 24 5.4. Route Discovery . . . . . . . . . . . . . . . . . . . . . 24
5.5. Route Maintenance . . . . . . . . . . . . . . . . . . . . 25 5.5. Route Maintenance . . . . . . . . . . . . . . . . . . . . 25
5.5.1. Active Link Monitoring . . . . . . . . . . . . . . . . 26 5.5.1. Active Link Monitoring . . . . . . . . . . . . . . . . 26
5.5.2. Updating Route Lifetimes During Packet Forwarding . . 26 5.5.2. Updating Route Lifetimes During Packet Forwarding . . 26
5.5.3. Route Error Generation . . . . . . . . . . . . . . . . 26 5.5.3. Route Error Generation . . . . . . . . . . . . . . . . 26
5.5.4. RERR Processing . . . . . . . . . . . . . . . . . . . 27 5.5.4. RERR Processing . . . . . . . . . . . . . . . . . . . 27
5.6. Unknown Message & TLV Types . . . . . . . . . . . . . . . 28 5.6. Unknown Message & TLV Types . . . . . . . . . . . . . . . 28
5.7. Advertising Network Addresses . . . . . . . . . . . . . . 28 5.7. Advertising Network Addresses . . . . . . . . . . . . . . 28
5.8. Simple Internet Attachment and Gatewaying . . . . . . . . 28 5.8. Simple Internet Attachment . . . . . . . . . . . . . . . . 29
5.9. Multiple Interfaces . . . . . . . . . . . . . . . . . . . 30 5.9. Multiple Interfaces . . . . . . . . . . . . . . . . . . . 30
5.10. Packet/Message Generation Limits . . . . . . . . . . . . . 30 5.10. DYMO Control Packet/Message Generation Limits . . . . . . 30
6. Configuration Parameters and Other Administrative Options . . 30 6. Configuration Parameters and Other Administrative Options . . 31
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32
7.1. DYMO Message Type Specification . . . . . . . . . . . . . 32 7.1. DYMO Message Type Specification . . . . . . . . . . . . . 32
7.2. Packet and Message TLV Type Specification . . . . . . . . 32 7.2. Packet and Message TLV Type Specification . . . . . . . . 32
7.3. Address Block TLV Specification . . . . . . . . . . . . . 33 7.3. Address Block TLV Specification . . . . . . . . . . . . . 33
8. Security Considerations . . . . . . . . . . . . . . . . . . . 33 8. Security Considerations . . . . . . . . . . . . . . . . . . . 33
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 34 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 34
10.1. Normative References . . . . . . . . . . . . . . . . . . . 34 10.1. Normative References . . . . . . . . . . . . . . . . . . . 34
10.2. Informative References . . . . . . . . . . . . . . . . . . 34 10.2. Informative References . . . . . . . . . . . . . . . . . . 34
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 35 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 35
Intellectual Property and Copyright Statements . . . . . . . . . . 36 Intellectual Property and Copyright Statements . . . . . . . . . . 36
1. Overview 1. Overview
The Dynamic MANET On-demand (DYMO) routing protocol enables reactive, The Dynamic MANET On-demand (DYMO) routing protocol enables reactive,
multihop unicast routing between participating DYMO routers. The multihop unicast routing between participating DYMO routers. The
basic operations of the DYMO protocol are route discovery and route basic operations of the DYMO protocol are route discovery and route
management. During route discovery, the originator's DYMO router maintenance.
initiates dissemination of a Route Request (RREQ) throughout the
network to find a route to the target's DYMO router. During this During route discovery, the originator's DYMO router initiates
hop-by-hop dissemination process, each intermediate DYMO router dissemination of a Route Request (RREQ) throughout the network to
records a route to the originator. When the target's DYMO router find a route to the target's DYMO router. During this hop-by-hop
receives the RREQ, it responds with a Route Reply (RREP) sent hop-by- dissemination process, each intermediate DYMO router records a route
hop toward the originator. Each intermediate DYMO router that to the originator. When the target's DYMO router receives the RREQ,
receives the RREP records a route to the target, and then the RREP is it responds with a Route Reply (RREP) sent hop-by-hop toward the
unicast hop-by-hop toward the originator. When the originator's DYMO originator. Each intermediate DYMO router that receives the RREP
router receives the RREP, routes have then been established between creates a route to the target, and then the RREP is unicast hop-by-
the originating DYMO router and the target DYMO router in both hop toward the originator. When the originator's DYMO router
receives the RREP, routes have then been established between the
originating DYMO router and the target DYMO router in both
directions. directions.
In order to preserve routes in use, DYMO routers extend route Route maintenance consists of two operations. In order to preserve
lifetimes upon successfully forwarding a packet. In order to react routes in use, DYMO routers extend route lifetimes upon successfully
to changes in the network topology, DYMO routers monitor links over forwarding a packet. In order to react to changes in the network
which traffic is moving. When a data packet is received for topology, DYMO routers monitor links over which traffic is flowing.
forwarding if a route for the destination is not known or the route When a data packet is received for forwarding and a route for the
is broken, then the DYMO router of source of the packet is notified. destination is not known or the route is broken, then the DYMO router
A Route Error (RERR) is sent toward the packet source to indicate the of source of the packet is notified. A Route Error (RERR) is sent
current route to a particular destination is broken. When the toward the packet source to indicate the current route to a
source's DYMO router receives the RERR, it deletes the route. If the particular destination is invalid or missing. When the source's DYMO
DYMO router later receives a packet for forwarding to the same router receives the RERR, it deletes the route. If the source's DYMO
destination, it must perform route discovery again. router later receives a packet for forwarding to the same
destination, it will need to perform route discovery again for that
destination.
DYMO uses sequence numbers to ensure loop freedom [Perkins99]. DYMO uses sequence numbers to ensure loop freedom [Perkins99].
Sequence numbers enable DYMO routers to determine the order of DYMO Sequence numbers enable DYMO routers to determine the order of DYMO
route discovery messages, thereby avoiding use of stale routing route discovery messages, thereby avoiding use of stale routing
information. information.
2. Applicability Statement 2. Applicability Statement
The DYMO routing protocol is designed for stub or disconnected mobile The DYMO routing protocol is designed for stub or disconnected mobile
ad hoc networks. DYMO handles a wide variety of mobility patterns by ad hoc networks (MANETs). DYMO handles a wide variety of mobility
dynamically determining routes on-demand. DYMO also handles a wide patterns by dynamically determining routes on-demand. DYMO also
variety of traffic patterns. In large networks DYMO is best suited handles a wide variety of traffic patterns. In networks with a large
for traffic scenarios where nodes communicate with only a portion of number of routers, DYMO is best suited for sparse traffic scenarios
the other nodes. where routers forward packets to with only a small portion of the
other DYMO routers, due to the reactive nature of route discovery and
route maintenance.
DYMO is applicable to memory constrained devices, since little DYMO is applicable to memory constrained devices, since minimal
routing state must be maintained in each DYMO router. Only routing routing state is maintained in each DYMO router. Only routing
information related to active sources and destinations must be information related to active sources and destinations is maintained,
maintained, in contrast to other routing protocols that require in contrast to other more proactive routing protocols that require
routing information to all routers within the routing region be routing information to all routers within the routing region be
maintained. maintained.
DYMO supports routers which have multiple interfaces participating in DYMO supports routers which have multiple interfaces participating in
the MANET. DYMO also supports nodes which have non-MANET interfaces the MANET. DYMO routers can also perform routing on behalf of other
to which hosts can attach. nodes, attached via participating or non-participating interfaces.
DYMO routers perform route discovery to find a route to a particular DYMO routers perform route discovery to find a route to a particular
destination. Therefore, DYMO routers must be configured to initiate destination. Therefore, DYMO routers MUST be configured to initiate
route discovery for certain destinations. When DYMO is the only route discovery on behalf of certain sources and find routes to
protocol interacting with the forwarding table, DYMO should be certain destinations. When DYMO is the only protocol interacting
configured to perform route discovery for all unknown unicast with the forwarding table, DYMO MAY be configured to perform route
destinations. discovery for all unknown unicast destinations.
DYMO should only utilizes bidirectional links. In the case of DYMO MUST only utilizes bidirectional links. In the case of possible
possible unidirectional links, either blacklists (see Section 7.2) or unidirectional links, either blacklists (see Section 7.2) or other
other means (e.g. only accepting RM from bidirectional links as means (e.g. only accepting RM from bidirectional links as indicated
indicated by NHDP [I-D.ietf-manet-nhdp]) of ensuring bi- by NHDP [I-D.ietf-manet-nhdp]) of ensuring bi-directionality should
directionality should be used. Otherwise, persistent packet loss may be used. Otherwise, persistent packet loss may occur.
occur.
The routing algorithm in DYMO may be operated at layers other than The routing algorithm in DYMO may be operated at layers other than
the network layer, using layer-appropriate addresses. Only the network layer, using layer-appropriate addresses. For operation
modification of the packet format is required. The routing algorithm at other layers only modification of the packet/message format should
need not change. Note that, using the DYMO algorithm with message be required; DYMO's routing algorithm need not change. Note that,
formats other than those specified in this document will not be using DYMO;s routing algorithm with formats other than those
interoperable. specified in this document MAY NOT be interoperable.
3. Terminology 3. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in [RFC2119].
Additionally, this document uses some terminology from Additionally, this document uses some terminology from
[I-D.ietf-manet-packetbb]. [I-D.ietf-manet-packetbb].
This document defines the following terminology: This document defines the following terminology:
Distance (Dist) Distance (Dist)
A metric of the distance a message or piece of information has A metric of the distance a message or piece of information has
traversed. The minimum value of distance is the number of IP hops traversed. The minimum value of distance is the number of IP hops
traversed. The maximum value is 65,535. traversed. The maximum value is 65,535.
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order of routing information generated and ensure loop-free order of routing information generated and ensure loop-free
routes. routes.
Forwarding Route Forwarding Route
A route that is used to forward data packets. Forwarding routes A route that is used to forward data packets. Forwarding routes
are generally maintained in a forwarding information base (FIB) or are generally maintained in a forwarding information base (FIB) or
the kernel forwarding/routing table. the kernel forwarding/routing table.
Originating Node (OrigNode) Originating Node (OrigNode)
The originating node is the DYMO router that creates a DYMO The originating node is the DYMO router that creates a DYMO
Message in an effort to disseminate some information. The control message in an effort to disseminate some routing
originating node is also referred to as a particular message's information. The originating node is also referred to as a
originator. particular message's originator.
Route Error (RERR) Route Error (RERR)
A RERR message is used indicate that a DYMO router does not have A RERR message is used indicate that a DYMO router does not have
forwarding route to one or more particular addresses. forwarding route to one or more particular addresses.
Route Reply (RREP) Route Reply (RREP)
A RREP message is used to disseminate routing information about A RREP message is used to disseminate routing information about
the RREP OrigNode to the RREP TargetNode and the DYMO routers the RREP OrigNode, to the RREP TargetNode and the DYMO routers
between them. between them.
Route Request (RREQ) Route Request (RREQ)
A RREQ message is issued to discover a valid route to a particular A RREQ message is issued to discover a valid route to a particular
destination address, called the RREQ TargetNode. When a DYMO destination address, called the RREQ TargetNode. When a DYMO
router processes a RREQ, it learns routing information on how to router processes a RREQ, it learns routing information on how to
reach the RREQ OrigNode. reach the RREQ OrigNode.
Target Node (TargetNode) Target Node (TargetNode)
The TargetNode is the ultimate destination of a message. The TargetNode is the ultimate destination of a message.
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The route table entry is a conceptual data structure. The route table entry is a conceptual data structure.
Implementations may use any internal representation that conforms to Implementations may use any internal representation that conforms to
the semantics of a route as specified in this document. the semantics of a route as specified in this document.
Conceptually, a route table entry has the following fields: Conceptually, a route table entry has the following fields:
Route.Address Route.Address
The IP (host or network) destination address of the node(s) The IP (host or network) destination address of the node(s)
associated with the routing table entry. associated with the routing table entry.
Route.Prefix
Indicates that the associated address is a network address, rather
than a host address. The value is the length of the netmask/
prefix.
Route.SeqNum Route.SeqNum
The DYMO SeqNum associated with this routing information. The DYMO SeqNum associated with this routing information.
Route.NextHopAddress Route.NextHopAddress
The IP address of the next DYMO router on the path toward the The IP address of the next DYMO router on the path toward the
Route.Address. Route.Address.
Route.NextHopInterface Route.NextHopInterface
The interface used to send packets toward the Route.Address. The interface used to send packets toward the Route.Address.
Route.Broken Route.Broken
A flag indicating whether this Route is broken. This flag is set A flag indicating whether this Route is broken. This flag is set
if the next hop becomes unreachable or in response to processing a if the next hop becomes unreachable or in response to processing a
RERR (see Section 5.5.4). RERR (see Section 5.5.4).
The following fields are optional: The following field is optional:
Route.Dist Route.Dist
A metric indicating the distance traversed before reaching the A metric indicating the distance traversed before reaching the
Route.Address node. Route.Address node.
Route.Prefix
Indicates that the associated address is a network address, rather
than a host address. The value is the length of the netmask/
prefix. If an address block does not have an associated
PREFIX_LENGTH TLV [I-D.ietf-manet-packetbb], the prefix may be
considered to have a prefix length equal to the address length in
bits.
Not including optional information may cause performance degradation, Not including optional information may cause performance degradation,
but it will not cause the protocol to operate incorrectly. but it will not cause the protocol to operate incorrectly.
In addition to a route table data structure, each route table entry In addition to a route table data structure, each route table entry
may have several timers associated with the information. These may have several timers associated with the information. These
timers/timeouts are discussed in Section 5.2.3. timers/timeouts are discussed in Section 5.2.3.
4.2. DYMO Messages 4.2. DYMO Messages
When describing DYMO protocol messages, it is necessary to refer to When describing DYMO protocol messages, it is necessary to refer to
skipping to change at page 8, line 27 skipping to change at page 8, line 30
| IP header | IP. | | IP header | IP. |
| UDP header | UDP. | | UDP header | UDP. |
| packetbb message header | MsgHdr. | | packetbb message header | MsgHdr. |
| packetbb message TLV | MsgTLV. | | packetbb message TLV | MsgTLV. |
| packetbb address blocks | AddBlk. | | packetbb address blocks | AddBlk. |
| packetbb address block TLV | AddTLV. | | packetbb address block TLV | AddTLV. |
+----------------------------+-------------------+ +----------------------------+-------------------+
Table 1 Table 1
4.2.1. Generalized MANET Packet and Message Structure 4.2.1. Generalized Packet and Message Structure
DYMO messages conform to the generalized packet and message format as DYMO messages conform to the generalized packet and message format as
described in [I-D.ietf-manet-packetbb]. Here is a brief description described in [I-D.ietf-manet-packetbb]. Here is a brief description
of the format. A packet is made up of messages. A message is made of the format. A packet is made up of messages. A message is made
up of a message header, message TLV block, and zero or more address up of a message header, message TLV block, and zero or more address
blocks. Each of the address blocks may also have an associated blocks. Each of the address blocks may also have an associated
address TLV block. address TLV block.
All DYMO messages specified in this document are sent using UDP to All DYMO messages specified in this document are sent using UDP to
the destination port MANET [I-D.ietf-manet-iana]. the destination port MANET [I-D.ietf-manet-iana].
Most DYMO messages are sent with the IP destination address set to Most DYMO messages are sent with the IP destination address set to
the link-local multicast address LL MANET ROUTERS unless otherwise the link-local multicast address LL-MANET-ROUTERS
stated. Therefore, all DYMO routers SHOULD subscribe to LL MANET [I-D.ietf-manet-iana] unless otherwise stated. Therefore, all DYMO
ROUTERS for receiving control packets. routers SHOULD subscribe to LL-MANET-ROUTERS [I-D.ietf-manet-iana]
for receiving control packets.
Unicast DYMO messages specified in this document are sent with the IP Unicast DYMO messages specified in this document are sent with the IP
destination set to the Route.NextHopAddress of the route to the destination set to the Route.NextHopAddress of the route to the
TargetNode. TargetNode.
The IPv4 TTL (IPv6 Hop Limit) field for DYMO messages is set to one The IPv4 TTL (IPv6 Hop Limit) field for all packets containing DYMO
(1) for all messages specified in this document. messages is set to 255. If a packet is received with a value other
than 255, it is discarded. This mechanism helps to ensures packets
have not passed through any intermediate routers, and it is known as
GTSM [RFC5082].
The length of an IP address (32 bits for IPv4 and 128 bits for IPv6) The length of an IP address (32 bits for IPv4 and 128 bits for IPv6)
inside a DYMO message depends on the IP packet header containing the inside a DYMO message depends on the IP packet header containing the
DYMO message/packet. For example, if the IP header uses IPv6 DYMO message/packet. For example, if the IP header uses IPv6
addresses then all messages and addresses contained in the payload addresses then all addresses contained in the payload use IPv6
use IPv6 addresses. In the case of mixed IPv6 and IPv4 addresses, addresses of the same length. In the case of mixed IPv6 and IPv4
please see [I-D.ietf-manet-packetbb]. addresses, please use the methods specified in
[I-D.ietf-manet-packetbb].
If a packet contains only a single DYMO message and no packet TLVs, If a packet contains only a single DYMO message and no packet TLVs,
it need not include a packet-header [I-D.ietf-manet-packetbb]. it need not include a packet-header [I-D.ietf-manet-packetbb].
The aggregation of multiple messages into a packet is not specified The aggregation of multiple messages into a packet is not specified
in this document, but the IP.SourceAddress and IP.DestinationAddress in this document, but the IP.SourceAddress and IP.DestinationAddress
of all contained messages must be the same. of all contained messages MUST be the same.
Implementations may choose to temporarily delay transmission of Implementations MAY choose to temporarily delay transmission of
messages for the purpose of aggregation (into a single packet) or to messages for the purpose of aggregation (into a single packet) or to
improve performance by introducing jitter [I-D.ietf-manet-jitter]. improve performance by introducing jitter [I-D.ietf-manet-jitter].
DYMO control packets SHOULD be given priority queue and channel
access.
4.2.2. Routing Messages (RM) - RREQ & RREP 4.2.2. Routing Messages (RM) - RREQ & RREP
Routing Messages (RMs) are used to disseminate routing information. Routing Messages (RMs) are used to disseminate routing information.
There are two DYMO message types that are considered to be routing There are two DYMO message types that are considered to be routing
messages (RMs): RREQ and RREP. They contain very similar information messages (RMs): RREQ and RREP. They contain very similar information
and function, but have slightly different processing rules. The main and function, but have slightly different processing rules. The main
difference between the two messages is that RREQ messages generally difference between the two messages is that RREQ messages generally
solicit a RREP, whereas a RREP is the response to RREQ. solicit a RREP, whereas a RREP is the response to RREQ.
RM creation and processing are described in Section 5.3. RM creation and processing are described in Section 5.3.
A RM requires the following information: A RM requires the following information:
IP.SourceAddress IP.SourceAddress
The IP address of the node currently sending this packet. This The IP address of the node currently sending this packet. This
field is generally filled automatically by the operating system field is generally filled automatically by the operating system
and should not require special handling. and should not require special handling.
IP.DestinationAddress IP.DestinationAddress
The IP address of the packet destination. For RREQ the The IP address of the packet destination. For RREQ the
IP.DestinationAddress is set to LL MANET ROUTERS. For RREP the IP.DestinationAddress is set to LL-MANET ROUTERS
IP.DestinationAddress is set to the NextHopAddress toward the RREP [I-D.ietf-manet-iana]. For RREP the IP.DestinationAddress is set
TargetNode. to the NextHopAddress toward the RREP TargetNode.
UDP.DestinationPort UDP.DestinationPort
The UDP destination port is set to MANET [I-D.ietf-manet-iana]. By default, the UDP destination port is set to MANET
[I-D.ietf-manet-iana].
MsgHdr.HopLimit MsgHdr.HopLimit
The remaining number of hops this message is allowed to traverse. The remaining number of hops this message is allowed to traverse.
AddBlk.TargetNode.Address AddBlk.TargetNode.Address
The IP address of the message TargetNode. In a RREQ the The IP address of the message TargetNode. In a RREQ the
TargetNode is the destination for which a forwarding route does TargetNode is the destination for which a forwarding route does
not exist and route discovery is being performed. In a RREP the not exist and route discovery is being performed. In a RREP the
TargetNode is the RREQ OrigNode DYMO router. The TargetNode TargetNode is the RREQ OrigNode DYMO router. The TargetNode
address is the first address in a routing message. address is the first address in a routing message.
AddBlk.OrigNode.Address AddBlk.OrigNode.Address
The IP address of the originator. In a RREQ the OrigNode is the The IP address of the originator and its associated prefix length.
source's DYMO router for which a route discovery is being In a RREQ the OrigNode is the source's DYMO router for which a
performed. In a RREP the OrigNode is the RREQ TargetNode's DYMO route discovery is being performed. In a RREP the OrigNode is the
router for which a RREP is being generated. This address is the RREQ TargetNode's DYMO router for which a RREP is being generated.
second address in the message for RREQ. This address is the second address in the message for RREQ.
OrigNode.AddTLV.SeqNum OrigNode.AddTLV.SeqNum
The DYMO sequence number of the originator's DYMO router. The DYMO sequence number of the originator's DYMO router.
A RM may optionally include the following information: A RM may optionally include the following information:
TargetNode.AddTLV.SeqNum TargetNode.AddTLV.SeqNum
The last known DYMO sequence number of the TargetNode. The last known DYMO sequence number of the TargetNode.
TargetNode.AddTLV.Dist TargetNode.AddTLV.Dist
The last known distance to the TargetNode. The last known distance to the TargetNode.
AddBlk.AdditionalNode.Address AddBlk.AdditionalNode.Address
The IP address of an additional node that can be reached via the The IP address of an additional node that can be reached via the
DYMO router adding this information. Each AdditionalNode.Address DYMO router adding this information. Each AdditionalNode.Address
must have an associated Node.SeqNum in the address TLV block. MUST include its prefix length. Each AdditionalNode.Address MUST
also have an associated Node.SeqNum in the address TLV block.
AdditionalNode.AddTLV.SeqNum AdditionalNode.AddTLV.SeqNum
The DYMO sequence number associated with this routing information. The DYMO sequence number associated with this routing information.
OrigNode.AddTLV.Dist OrigNode.AddTLV.Dist
A metric of the distance to reach the associated OrigNode.Address. A metric of the distance to reach the associated OrigNode.Address.
This field is incremented by at least one at each intermediate This field is incremented by at least one at each intermediate
DYMO router. DYMO router.
AdditionalNode.AddTLV.Dist AdditionalNode.AddTLV.Dist
A metric of the distance to reach the associated A metric of the distance to reach the associated
AdditionalNode.Address. This field is incremented by at least one AdditionalNode.Address. This field is incremented by at least one
at each intermediate DYMO router. at each intermediate DYMO router.
OrigNode.AddTLV.Prefix
The OrigNode.Address is a network address with a particular prefix
length.
AdditionalNode.AddTLV.Prefix
The AdditionalNode.Address is a network address with a particular
prefix length.
Example IPv4 RREQ Example IPv4 RREQ
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
IP Header IP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP.SourceAddress | | IP.SourceAddress |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP.DestinationAddress = LL MANET ROUTERS | | IP.DestinationAddress = LL-MANET-ROUTERS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... | IP TTL/HopLimit = 255 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
UDP Header UDP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port = MANET | | Destination Port = MANET |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...
Message Header Message Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RREQ-type | Rsv |N|1|1|0|1| msg-size=23 | | RREQ-type |R|C|N|1|1|0|1|0| msg-size=23 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-hoplimit | | msg-hoplimit |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
... Message TLV Block
Message Body - Message TLV Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-tlv-block-size=0 | | msg-tlv-block-size=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message Body - Address Block Message Body - Address Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Number Addrs=2 | Resv |0|1|0| HeadLength=3 | Head : |Number Addrs=2 | Rsv |0|0|0|1|0| HeadLength=3 | Head :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: Head (cont) | Target.Tail | Orig.Tail | : Head (cont) | Target.Tail | Orig.Tail |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message Body - Address Block TLV Block Message Body - Address Block TLV Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| tlv-block-size=6 |DYMOSeqNum-type|Rsv|0|1|0|0|0|0| | tlv-block-size=6 |DYMOSeqNum-type|Rsv|0|1|0|0|0|0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Index-start=1 | tlv-length=2 | Orig.SeqNum | | Index-start=1 | tlv-length=2 | Orig.SeqNum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 13, line 20 skipping to change at page 13, line 13
RERR creation and processing are described in Section 5.5. RERR creation and processing are described in Section 5.5.
A RERR requires the following information: A RERR requires the following information:
IP.SourceAddress IP.SourceAddress
The IP address of the node currently sending this packet. This The IP address of the node currently sending this packet. This
field is generally filled automatically by the operating system field is generally filled automatically by the operating system
and should not require special handling. and should not require special handling.
IP.DestinationAddress IP.DestinationAddress
The IP address is set to LL MANET ROUTERS. The IP address is set to LL-MANET-ROUTERS [I-D.ietf-manet-iana].
UDP.DestinationPort UDP.DestinationPort
The UDP destination port is set to MANET [I-D.ietf-manet-iana]. By default, the UDP destination port is set to MANET
[I-D.ietf-manet-iana].
MsgHdr.HopLimit MsgHdr.HopLimit
The remaining number of hops this message is allowed to traverse. The remaining number of hops this message is allowed to traverse.
AddBlk.UnreachableNode.Address AddBlk.UnreachableNode.Address
The IP address of an UnreachableNode. Multiple unreachable The IP address of an UnreachableNode and its associated prefix
addresses may be included in a RERR. length. Multiple unreachable addresses may be included in a RERR.
A Route Error may optionally include the following information: A Route Error may optionally include the following information:
UnreachableNode.AddTLV.SeqNum UnreachableNode.AddTLV.SeqNum
The last known DYMO sequence number of the unreachable node. If a The last known DYMO sequence number of the unreachable node. If a
SeqNum for an address is not included, it is assumed to be SeqNum for an address is not included, it is assumed to be
unknown. This case occurs when a node receives a message to unknown. This case occurs when a node receives a message to
forward to a destination for which it does not have any forward to a destination for which it does not have any
information in its routing table. information in its routing table.
skipping to change at page 14, line 9 skipping to change at page 14, line 9
The last known DYMO sequence number of the unreachable node. If a The last known DYMO sequence number of the unreachable node. If a
SeqNum for an address is not included, it is assumed to be SeqNum for an address is not included, it is assumed to be
unknown. This case occurs when a node receives a message to unknown. This case occurs when a node receives a message to
forward to a destination for which it does not have any forward to a destination for which it does not have any
information in its routing table. information in its routing table.
Example IPv4 RERR Example IPv4 RERR
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
IP Header IP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP.SourceAddress | | IP.SourceAddress |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP.DestinationAddress = LL MANET ROUTERS | | IP.DestinationAddress = LL-MANET-ROUTERS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... | IP.TTL/HopLimit = 255 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
UDP Header UDP Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port = MANET | | Destination Port = MANET |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...
Message Header Message Header
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RERR-type |Resv |0|1|1|0|1| msg-size=15 | | RERR-type |R|C|N|1|1|0|1|0| msg-size=15 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-hoplimit | | msg-hoplimit |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
... Message TLV Block
Message Body +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | msg-tlv-block-size=0 |
| msg-tlv-block-size=0 |Number Addrs=1 | Resv |0|1|1| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message Body - Address Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Number Addrs=1 | Rsv |0|0|0|1|1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Unreachable.Address | | Unreachable.Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message Body - Address Block TLV Block
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TLV-blk-size=0 | | TLV-blk-size=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 Figure 2
5. Detailed Operation 5. Detailed Operation
5.1. DYMO Sequence Numbers 5.1. DYMO Sequence Numbers
DYMO sequence numbers allow nodes to judge the freshness of routing DYMO sequence numbers allow nodes to judge the freshness of routing
skipping to change at page 15, line 18 skipping to change at page 15, line 18
own DYMO sequence number (OwnSeqNum), a 16-bit unsigned integer. The own DYMO sequence number (OwnSeqNum), a 16-bit unsigned integer. The
circumstances for ThisNode to incrementing its OwnSeqNum are circumstances for ThisNode to incrementing its OwnSeqNum are
described in Section 5.3. described in Section 5.3.
5.1.2. Numerical Operations on OwnSeqNum 5.1.2. Numerical Operations on OwnSeqNum
When ThisNode increments its OwnSeqNum (as described in Section 5.3) When ThisNode increments its OwnSeqNum (as described in Section 5.3)
it MUST do so by treating the sequence number value as an unsigned it MUST do so by treating the sequence number value as an unsigned
number. number.
Note: The sequence number zero (0) is reserved.
5.1.3. OwnSeqNum Rollover 5.1.3. OwnSeqNum Rollover
If the sequence number has been assigned to be the largest possible If the sequence number has been assigned to be the largest possible
number representable as a 16-bit unsigned integer (i.e., 65,535), number representable as a 16-bit unsigned integer (i.e., 65,535),
then the sequence number is set to 256 when incremented. Setting the then the sequence number is set to 256 when incremented. Setting the
sequence number to 256 allows other nodes to detect that the number sequence number to 256 allows other nodes to detect that the number
has rolled over and the node has not lost its sequence number. has rolled over and the node has not lost its sequence number.
5.1.4. Actions After OwnSeqNum Loss 5.1.4. Actions After OwnSeqNum Loss
A node should maintain its sequence number in persistent storage, A DYMO router SHOULD maintain its sequence number in persistent
between reboots. storage.
If a node's OwnSeqNum is lost, it must take certain actions to avoid If a DYMO router's OwnSeqNum is lost, it MUST take certain actions to
creating routing loops. To prevent this possibility after OwnSeqNum avoid creating routing loops. To prevent this possibility after
loss a node MUST wait for at least ROUTE_DELETE_TIMEOUT before fully OwnSeqNum loss a DYMO router MUST wait for at least
participating in the DYMO routing protocol. If a DYMO control ROUTE_DELETE_TIMEOUT before fully participating in the DYMO routing
message is received during this waiting period, the node SHOULD protocol. If a DYMO control message is received during this waiting
process it normally but MUST NOT transmit or retransmit any DYMO period, the DYMO router SHOULD process it normally but MUST NOT
messages. If a data packet is received for forwarding to another transmit or retransmit any DYMO messages. If a data packet is
destination during this waiting period, the node MUST generate a RERR received for forwarding to another destination during this waiting
message indicating that this route is not available and reset its period, the DYMO router MUST generate a RERR message indicating that
waiting timeout. At the end of the waiting period a node sets its this route is not available and reset its waiting timeout. At the
OwnSeqNum to one (1). end of the waiting period the DYMO router sets its OwnSeqNum to one
(1) and begins participating.
The longest a node must wait is ROUTE_AGE_MAX_TIMEOUT. At the end of The longest a node need wait is ROUTE_AGE_MAX_TIMEOUT. At the end of
the maximum waiting period a node sets its OwnSeqNum to one (1) and the maximum waiting period a node sets its OwnSeqNum to one (1) and
begins participating. begins participating.
5.2. DYMO Routing Table Operations 5.2. DYMO Routing Table Operations
5.2.1. Judging Routing Information's Usefulness 5.2.1. Judging Routing Information's Usefulness
Given a route table entry (Route.SeqNum, Route.Dist, and Given a route table entry (Route.SeqNum, Route.Dist, and
Route.Broken) and new incoming routing information for a particular Route.Broken) and new incoming routing information for a particular
node in a RM (Node.SeqNum, Node.Dist, and RM message type - RREQ/ node in a RM (Node.SeqNum, Node.Dist, and RM message type - RREQ/
skipping to change at page 16, line 21 skipping to change at page 16, line 21
determine its usefulness. Incoming routing information is classified determine its usefulness. Incoming routing information is classified
as follows: as follows:
1. Stale 1. Stale
If Node.SeqNum - Route.SeqNum < 0 (using signed 16-bit arithmetic) If Node.SeqNum - Route.SeqNum < 0 (using signed 16-bit arithmetic)
the incoming information is stale. Using stale routing the incoming information is stale. Using stale routing
information is not allowed, since doing so might result in routing information is not allowed, since doing so might result in routing
loops. loops.
(Node.SeqNum - Route.SeqNum < 0) (Node.SeqNum - Route.SeqNum < 0)
using 16-bit arithmetic
2. Loop-possible 2. Loop-possible
If Node.SeqNum == Route.SeqNum the incoming information may cause If Node.SeqNum == Route.SeqNum the incoming information may cause
loops if used; in this case additional information must be loops if used; in this case additional information MUST be
examined. If Route.Dist or Node.Dist is unknown or zero (0), then examined. If Route.Dist or Node.Dist is unknown or zero (0), then
the routing information is loop-possible. If Node.Dist > the routing information is loop-possible. If Node.Dist >
Route.Dist + 1, then the routing information is loop-possible. Route.Dist + 1, then the routing information is loop-possible.
Using loop-possible routing information is not allowed, otherwise Using loop-possible routing information is not allowed, otherwise
routing loops may be formed. routing loops may be formed.
(Node.SeqNum == Route.SeqNum) AND (Node.SeqNum == Route.SeqNum) AND
((Node.Dist is unknown) OR ((Node.Dist is unknown) OR
(Route.Dist is unknown) OR (Route.Dist is unknown) OR
(Node.Dist > Route.Dist + 1)) (Node.Dist > Route.Dist + 1))
skipping to change at page 17, line 18 skipping to change at page 17, line 18
- Route.SeqNum > 0 (using 16-bit signed arithmetic). In the case - Route.SeqNum > 0 (using 16-bit signed arithmetic). In the case
of equal sequence numbers, the information is superior in multiple of equal sequence numbers, the information is superior in multiple
cases: (case i) if Node.Dist < Route.Dist; (case ii) if Node.Dist cases: (case i) if Node.Dist < Route.Dist; (case ii) if Node.Dist
== Route.Dist + 1 AND Route.Broken == true (a broken route is == Route.Dist + 1 AND Route.Broken == true (a broken route is
being repaired); (case iii) if Node.Dist == Route.Dist AND it is a being repaired); (case iii) if Node.Dist == Route.Dist AND it is a
RREP (RREP with equal distance are forwarded) OR Route.Broken == RREP (RREP with equal distance are forwarded) OR Route.Broken ==
true (a broken route is being repaired). For completeness, we true (a broken route is being repaired). For completeness, we
provide the following (optimized) pseudo-code. provide the following (optimized) pseudo-code.
(Node.SeqNum - Route.SeqNum > 0) OR (Node.SeqNum - Route.SeqNum > 0) OR
using 16-bit arithmetic
((Node.SeqNum == Route.SeqNum) AND ((Node.SeqNum == Route.SeqNum) AND
((Node.Dist < Route.Dist) OR ((Node.Dist < Route.Dist) OR
((Node.Dist == Route.Dist + 1) AND (Route.Broken == true)) OR ((Node.Dist == Route.Dist + 1) AND (Route.Broken == true)) OR
((Node.Dist == Route.Dist) AND ((Node.Dist == Route.Dist) AND
((RM is RREP) OR (Route.Broken == true))))) ((RM is RREP) OR (Route.Broken == true)))))
5.2.2. Creating or Updating a Route Table Entry with New Routing 5.2.2. Creating or Updating a Route Table Entry with Received Superior
Information Routing Information
The route table entry is populated with the following information: The route table entry is populated with the following information:
1. the Route.Address is set to Node.Address, 1. the Route.Address is set to Node.Address,
2. the Route.SeqNum is set to the Node.SeqNum, 2. the Route.Prefix is set to the Node.Prefix.
3. the Route.NextHopAddress is set to the node that transmitted this 3. the Route.SeqNum is set to the Node.SeqNum,
4. the Route.NextHopAddress is set to the node that transmitted this
DYMO RM packet (i.e., the IP.SourceAddress), DYMO RM packet (i.e., the IP.SourceAddress),
4. the Route.NextHopInterface is set to the interface that this DYMO 5. the Route.NextHopInterface is set to the interface that this DYMO
packet was received on, packet was received on,
5. if known, the Route.Dist is set to the Node.Dist, 6. if known, the Route.Dist is set to the Node.Dist,
6. if known, the Route.Prefix is set to the Node.Prefix.
Fields without known values are not populated with any value. Fields without known values are not populated with any value.
Previous timers for this route table entry are removed. A timer for Previous timers for this route table entry are removed. A timer for
the minimum delete timeout (ROUTE_AGE_MIN) is set to the minimum delete timeout (ROUTE_AGE_MIN) is set to
ROUTE_AGE_MIN_TIMEOUT. A timer to indicate a recently learned route ROUTE_AGE_MIN_TIMEOUT. A timer for the maximum delete timeout
(ROUTE_NEW) is set to ROUTE_NEW_TIMEOUT. A timer for the maximum (ROUTE_AGE_MAX). ROUTE_AGE_MAX is set to Node.AddTLV.VALIDITY_TIME
delete timeout (ROUTE_AGE_MAX). ROUTE_AGE_MAX is set to [I-D.ietf-manet-timetlv] if included; otherwise, ROUTE_AGE_MAX is set
Node.AddTLV.MaxAge if included; otherwise, ROUTE_AGE_MAX is set to to ROUTE_AGE_MAX_TIMEOUT. The usage of these timers and others are
ROUTE_AGE_MAX_TIMEOUT. The usage of these timers and others are
described in Section 5.2.3. described in Section 5.2.3.
At this point, a forwarding route should be installed. Afterward, At this point, a forwarding route should be created. Afterward, the
the route can be used to send any queued data packets and forward any route can be used to send any queued data packets and forward any
incoming data packets for Route.Address. This route also fulfills incoming data packets for Route.Address. This route also fulfills
any outstanding route discovery attempts for Node.Address. any outstanding route discovery attempts for Node.Address.
5.2.3. Route Table Entry Timeouts 5.2.3. Route Table Entry Timeouts
5.2.3.1. Minimum Delete Timeout (ROUTE_AGE_MIN) 5.2.3.1. Minimum Delete Timeout (ROUTE_AGE_MIN)
When a DYMO router transmits a RM, other DYMO routers expect the When a DYMO router transmits a RM, other DYMO routers expect the
transmitting DYMO router to have a forwarding route to the RM transmitting DYMO router to have a forwarding route to the RM
originator. After updating a route table entry, it should be originator. After updating a route table entry, it should be
maintained for at least ROUTE_AGE_MIN. Failure to maintain the maintained for at least ROUTE_AGE_MIN. Failure to maintain the
information might result in lost messages/packets, or in the worst information might result in lost messages/packets, or in the worst
case scenario several duplicate messages. case scenario several duplicate messages.
After the ROUTE_AGE_MIN timeout a route can safely be deleted. After the ROUTE_AGE_MIN timeout a route can safely be deleted.
5.2.3.2. Maximum Delete Timeout (ROUTE_AGE_MAX) 5.2.3.2. Maximum Delete Timeout (ROUTE_AGE_MAX)
Sequence number information is time sensitive, and must be deleted Sequence number information is time sensitive, and MUST be deleted
after a time in order to avoid conflicts due to reboots and after a time in order to ensure loop-free routing.
rollovers. When a DYMO router has lost its sequence number (e.g, due
to daemon reboot or node replacement) the DYMO router must wait until
routing information associated with that IP address and sequence
number are no longer maintained by other DYMO routers in the network
to ensure loop-free routing.
After the ROUTE_AGE_MAX timeout a route must be deleted. All After the ROUTE_AGE_MAX timeout a route MUST be deleted. All
information about the route is deleted upon ROUTE_AGE_MAX timeout. information about the route is deleted upon ROUTE_AGE_MAX timeout.
If a forwarding route exists it is also removed. If a forwarding route exists it is also removed.
5.2.3.3. New Information Timeout (ROUTE_NEW) 5.2.3.3. Recently Used Timeout (ROUTE_USED)
As time progresses the likelihood that a route remains intact
decreases, if the network nodes are mobile. Maintaining and using
old routing information can lead to many DYMO messages and excess
route discovery delay.
After the ROUTE_NEW timeout if the route has not been used, a timer
for deleting the route (ROUTE_DELETE) is set to ROUTE_DELETE_TIMEOUT.
5.2.3.4. Recently Used Timeout (ROUTE_USED)
When a route is used to forward data packets, this timer is set to When a route is used to forward data packets, this timer is set to
expire after ROUTE_USED_TIMEOUT. This operation is also discussed in expire after ROUTE_USED_TIMEOUT. This operation is also discussed in
Section 5.5.2. Section 5.5.2.
If a route has not been used recently, then a timer for ROUTE_DELETE If a route has not been used recently, then a timer for ROUTE_DELETE
is set to ROUTE_DELETE_TIMEOUT. is set to ROUTE_DELETE_TIMEOUT.
5.2.3.5. Delete Information Timeout (ROUTE_DELETE) 5.2.3.4. Delete Information Timeout (ROUTE_DELETE)
As time progresses the likelihood that old routing information is As time progresses the likelihood that old routing information is
useful decreases, especially if the network nodes are mobile. useful decreases, especially if the network nodes are mobile.
Therefore, old information should be deleted. Therefore, old information should be deleted.
After the ROUTE_DELETE timeout, the routing table entry should be After the ROUTE_DELETE timeout, the routing table entry should be
deleted. If a forwarding route exists, it should also be removed. deleted. If a forwarding route exists, it should also be removed.
5.3. Routing Messages 5.3. Routing Messages
5.3.1. RREQ Creation 5.3.1. RREQ Creation
When a DYMO router creates a RREQ it SHOULD increment its OwnSeqNum When a DYMO router creates a RREQ it SHOULD increment its OwnSeqNum
by one (1) according to the rules specified in Section 5.1.2. by one (1) according to the rules specified in Section 5.1.2.
Incrementing OwnSeqNum will ensure that all nodes with existing Incrementing OwnSeqNum will ensure that all nodes with existing
routing information to consider this new information fresh. If the routing information will consider this new information superior to
sequence number is not incremented, certain DYMO routers might not existing routing table information. If the sequence number is not
consider this information useful if they have superior information incremented, certain DYMO routers might not consider this information
already. superior, if they have existing better routing information already.
First, ThisNode adds the AddBlk.TargetNode.Address to the RREQ; the First, ThisNode adds the AddBlk.TargetNode.Address to the RREQ; the
IP.DestinationAddress for which a forwarding route does not exist. unicast IP Destination Address for which a forwarding route does not
exist.
If a previous value of the TargetNode.SeqNum is known (from a routing If a previous value of the TargetNode.SeqNum is known (from a routing
table entry using longest-prefix matching), it SHOULD be placed in table entry using longest-prefix matching), it SHOULD be placed in
TargetNode.AddTLV.SeqNum in all but the last RREQ attempt. If a TargetNode.AddTLV.SeqNum in all but the last RREQ attempt. If a
TargetNode.SeqNum is not included, it is assumed to be unknown by TargetNode.SeqNum is not included, it is assumed to be unknown by
processing nodes. This operation ensures that no intermediate DYMO processing nodes. This operation ensures that no intermediate DYMO
routers reply, and ensures that the TargetNode's DYMO router routers reply, and ensures that the TargetNode's DYMO router
increments its sequence number. increments its sequence number.
Similarly, if a previous value of the TargetNode.Dist is known, it Next, the node adds AddBlk.OrigNode.Address, its prefix, and the
SHOULD be placed in TargetNode.AddTLV.Dist. Otherwise, the OrigNode.AddTLV.SeqNum (OwnSeqNum) to the RM.
TargetNode.AddTLV.Dist is not included and assumed unknown by
processing nodes.
Next, the node adds AddBlk.OrigNode.Address to the RM and the
OrigNode.AddTLV.SeqNum (OwnSeqNum) in an address block TLV.
The OrigNode.Address is the address of the DYMO router that is The OrigNode.Address is the address of the DYMO router that is
initiating this route discovery. The OrigNode.Address must be a initiating this route discovery. The OrigNode.Address MUST be a
routable IP address. If this DYMO router is performing route unicast IP address. If this DYMO router is performing route
discovery on behalf of an attached node (i.e. the source of the data discovery on behalf of an attached node (i.e. the source of the data
packet causing this route discovery), the DYMO router MUST advertise packet causing this route discovery), the DYMO router MUST advertise
it's address and prefix that contain the source's address. This an address and prefix that contain the source's address. This
information will be used by nodes to create a route toward the information will be used by nodes to create a route toward the
OrigNode, enable delivery of a RREP, and eventually for data packets. OrigNode, enabling delivery of a RREP, and eventually used for proper
forwarding of data packets.
If OrigNode.Dist is included it is set to a number greater than zero If OrigNode.Dist is included it is set to a number greater than zero
(0). (0).
The MsgHdr.HopLimit should be set to MAX_HOPLIMIT, but may be set The MsgHdr.HopLimit SHOULD be set to MAX_HOPLIMIT.
smaller.
For RREQ, the MsgHdr.HopLimit may be set in accordance with an For RREQ, the MsgHdr.HopLimit MAY be set in accordance with an
expanding ring search as described in [RFC3561] to limit the RREQ expanding ring search as described in [RFC3561] to limit the RREQ
propagation to a subset of the network and possibly reduce route propagation to a subset of the local network and possibly reduce
discovery overhead. route discovery overhead.
The IP.DestinationAddress for RREQ is set to LL MANET ROUTERS. The IP.DestinationAddress for RREQ is set to LL-MANET-ROUTERS.
5.3.2. RREP Creation 5.3.2. RREP Creation
First, the AddBlk.TargetNode.Address is added to the RREP. The
TargetNode is the ultimate destination of this RREP; the RREQ
OrigNode.Address.
Next, AddBlk.OrigNode.Address and prefix is added to the RREP. The
AddBlk.OrigNode.Address MUST be a unicast IP address. If the RREQ
TargetNode is this DYMO router, its address is added to the RREP as
the OrigNode.Address. If the RREQ TargetNode is attached to this
DYMO router, ThisNode MUST advertise an address and prefix that
contain the RREQ TargetNode.Address.
When the TargetNode's DYMO router creates a RREP, if the When the TargetNode's DYMO router creates a RREP, if the
TargetNode.SeqNum was not included in the RREQ it MUST increment its TargetNode.SeqNum was not included in the RREQ, ThisNode MUST
OwnSeqNum by one (1) according to the rules specified in increment its OwnSeqNum by one (1) according to the rules specified
Section 5.1.2. in Section 5.1.2.
If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum - If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum -
OwnSeqNum < 0 (using signed 16-bit arithmetic), OwnSeqNum SHOULD be OwnSeqNum < 0 (using signed 16-bit arithmetic), OwnSeqNum SHOULD be
incremented by one (1) according to the rules specified in incremented by one (1) according to the rules specified in
Section 5.1.2. Section 5.1.2.
If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum == If TargetNode.SeqNum is included in the RM and TargetNode.SeqNum ==
OwnSeqNum (using signed 16-bit arithmetic) and Dist will not be OwnSeqNum (using signed 16-bit arithmetic) and Dist will not be
included in the RREP being generated, OwnSeqNum SHOULD be incremented included in the RREP being generated, OwnSeqNum SHOULD be incremented
by one (1) according to the rules specified in Section 5.1.2. by one (1) according to the rules specified in Section 5.1.2.
If OwnSeqNum is not incremented the routing information might be If OwnSeqNum is not incremented the routing information might be
considered stale. In this case, the RREP would not reach the RREP considered stale. In this case, the RREP might not reach the RREP
Target. Target.
First, the AddBlk.TargetNode.Address is added to the RREP. The After any of the sequence number operations above, the RREP
TargetNode is the ultimate destination of this RREP; the RREQ OrigNode.AddTLV.SeqNum (OwnSeqNum) MUST also added to the RREP.
OrigNode.Address.
Next, AddBlk.OrigNode.Address is added to the RREP. The
AddBlk.OrigNode.Address must be a routable IP address. If the RREQ
TargetNode is this DYMO router, its address added to the RREP as the
OrigNode.Address. If the RREQ TargetNode is attached to this DYMO
router, it MUST advertise its address and prefix that contain the
RREQ TargetNode.Address. The RREP OrigNode.AddTLV.SeqNum (OwnSeqNum)
must also added to the RREP.
Other AddTLVs in the RREP for the OrigNode and TargetNode SHOULD be Other AddTLVs in the RREP for the OrigNode and TargetNode SHOULD be
included and set accordingly. If OrigNode.Dist is included it is set included and set accordingly. If OrigNode.Dist is included it is set
to a number greater than zero (0). to a number greater than zero (0).
The MsgHdr.HopLimit is set to MAX_HOPLIMIT. The MsgHdr.HopLimit is set to MAX_HOPLIMIT.
The IP.DestinationAddress for RREP is set to the IP address of the The IP.DestinationAddress for RREP is set to the IP address of the
Route.NextHopAddress for the route to the RREP TargetNode. Route.NextHopAddress for the route to the RREP TargetNode.
skipping to change at page 21, line 29 skipping to change at page 21, line 12
Sometimes a DYMO router other than the TargetNode's DYMO router (call Sometimes a DYMO router other than the TargetNode's DYMO router (call
it an "intermediate DYMO router") has routing information that can it an "intermediate DYMO router") has routing information that can
satisfy an incoming RREQ. An intermediate DYMO router can issue a satisfy an incoming RREQ. An intermediate DYMO router can issue a
intermediate DYMO router RREP on behalf of the TargetNode's DYMO intermediate DYMO router RREP on behalf of the TargetNode's DYMO
router. router.
Before creating a intermediate DYMO router RREP, OwnSeqNum SHOULD be Before creating a intermediate DYMO router RREP, OwnSeqNum SHOULD be
incremented by one (1) according to the rules specified in incremented by one (1) according to the rules specified in
Section 5.1.2. Section 5.1.2.
If OwnSeqNum is not incremented the routing information might be If OwnSeqNum is not incremented the routing information about
considered stale by a processing DYMO router. In this case, the RREP ThisNode might be considered stale by a processing DYMO router. In
would not reach the RREP Target. this case, the RREP would not reach the RREP TargetNode.
When an intermediate DYMO router originates a RREP in response to a When an intermediate DYMO router originates a RREP in response to a
RREQ on behalf of the TargetNode's DYMO router, it sends the RREP to RREQ on behalf of the TargetNode's DYMO router, it sends the RREP to
the RREQ OrigNode with additional routing information (Address, the RREQ OrigNode with additional routing information (Address,
SeqNum, Prefix, Dist, etc.) about the RREQ TargetNode. Appending Prefix, SeqNum, Dist, etc.) about the RREQ TargetNode. Appending
additional routing information is described in Section 5.3.5. additional routing information is described in Section 5.3.5.
The Intermediate DYMO router SHOULD also issue a RREP to the RREQ The Intermediate DYMO router SHOULD also issue a RREP to the RREQ
TargetNode, so that the RREQ TargetNode receives routing information TargetNode, so that the RREQ TargetNode receives routing information
on how to reach the RREQ OrigNode. on how to reach the RREQ OrigNode.
When an intermediate DYMO router creates this RREP, it sends a RREP When an intermediate DYMO router creates this RREP, it sends a RREP
to the RREQ TargetNode with additional routing information (Address, to the RREQ TargetNode with additional routing information (Address,
SeqNum, Dist, Prefix, etc.) about the RREQ OrigNode. Prefix, SeqNum, Dist, etc.) about the RREQ OrigNode.
5.3.4. RM Processing 5.3.4. RM Processing
Before processing a RM, the DYMO router checks the IP.Destination to ThisNode first checks whether AddBlk.OrigNode.Address is an address
ensure that it was sent to LL MANET ROUTERS.
When a RM is received the MsgHdr.HopLimit is decremented by one (1).
For each address (except the TargetNode) in the RM that includes
AddTLV.Dist information, the AddTLV.Dist information is incremented
by at lease one (1).
Next, ThisNode checks whether AddBlk.OrigNode.Address is an address
handled by this DYMO router. If this node is the originating DYMO handled by this DYMO router. If this node is the originating DYMO
router, the RM is dropped. router, the RM is dropped.
Before processing a RREQ, the DYMO router checks the IP.Destination
to ensure that it was sent to LL-MANET-ROUTERS [I-D.ietf-manet-iana].
If the RREQ was not sent to LL-MANET-ROUTERS, it SHOULD be discarded
and further processing stopped.
Next, ThisNode checks if the AddBlk.OrigNode.Address is a valid
unicast IP address. If the address is not a valid unicast IP
address, the messages MUST be discarded and further processing
stopped.
Next, ThisNode checks whether its routing table has an entry to the Next, ThisNode checks whether its routing table has an entry to the
AddBlk.OrigNode.Address using longest-prefix matching [RFC1812]. If AddBlk.OrigNode.Address using longest-prefix matching [RFC1812]. If
a route does not exist and the address is a unicast address, then the a route does not exist, then the new routing information is
new routing information is considered fresh and a new route table considered fresh and a new route table entry is created and updated
entry is created and updated as described in Section 5.2.2. If a as described in Section 5.2.2. If a route table entry does exists,
route table entry does exists, the incoming routing information is the incoming routing information is compared with the route table
compared with the route table entry following the procedure described entry following the procedure described in Section 5.2.1. If the
in Section 5.2.1. If the incoming routing information is considered incoming routing information is considered superior, the route table
superior, the route table entry is updated as described in entry is updated as described in Section 5.2.2.
Section 5.2.2.
After processing the OrigNode's routing information, then each After processing the OrigNode's routing information, then each
address that is not the TargetNode should be considered for creating address that is not the TargetNode should be considered for creating
and updating routes. Creating and updating routes to other nodes can and updating routes. Creating and updating routes to other nodes can
eliminate RREQ for those IP destinations, in the event that data eliminate RREQ for those IP destinations, in the event that data
needs to be forwarded to the IP destination(s) in the near future. needs to be forwarded to the IP destination(s) now or in the near
future.
For each of the additional addresses considered, if the address is a For each of the additional addresses considered, ThisNode first
unicast address and the routing table does not have a matching route checks the that the address is a unicast IP address. If the address
using longest-prefix matching, then a route is created and updated as is not a unicast IP address, the address and all related information
described in Section 5.2.2. If a route table entry exists, the MUST be removed. If the routing table does not have a matching route
incoming routing information is compared with the route table entry for this additional address using longest-prefix matching, then a
following the procedure described in Section 5.2.1. If the incoming route is created and updated as described in Section 5.2.2. If a
routing information is considered superior, the route table entry is route table entry exists, the incoming routing information is
updated as described in Section 5.2.2. compared with the route table entry following the procedure described
in Section 5.2.1. If the incoming routing information is considered
superior, the route table entry is updated as described in
Section 5.2.2.
If the routing information for an AdditionalNode.Address is not a If the routing information for an AdditionalNode.Address is not
unicast address and considered superior, then it is removed from the considered superior, then it is removed from the RM. Removing this
RM. Removing this information ensures that the information is not information ensures that the information is not propagated.
propagated.
At this point, if the routing information for the OrigNode was not At this point, if the routing information for the OrigNode was not
superior then this RM should be discarded and no further processing superior then this RM SHOULD be discarded and no further processing
of this message is performed. of this message SHOULD be performed.
If the ThisNode is the DYMO router for the TargetNode and this RM is If the ThisNode is the DYMO router responsible for the TargetNode and
a RREQ, then ThisNode responds with a RREP to the RREQ OrigNode (the this RM is a RREQ, then ThisNode responds with a RREP to the RREQ
new RREP's TargetNode). Alternatively, to distribute routing OrigNode (the new RREP's TargetNode). The procedure for issuing a
information about ThisNode (the RREQ TargetNode) more widely, new RREP is described in Section 5.3.2. Note: it is important that
ThisNode may optionally perform a RREQ; by issuing a RREQ with when creating the RREP, the RREP OrigNode.Address for ThisNode be
ThisNode listed as the TargetNode, using the procedure in within the same prefix as the RREQ TargetNode.Address. At this
Section 5.3.1. The procedure for issuing a new RREP is described in point, ThisNode need not perform any more operations for this RM.
Section 5.3.2. Note: it is important that when creating the RREP,
the RREP OrigNode.Address be the same as the RREQ TargetNode.Address, Alternatively ThisNode MAY choose to distribute routing information
if ThisNode is responsible for several addresses. At this point, about ThisNode (the RREQ TargetNode) more widely, ThisNode MAY
ThisNode need not perform any more operations for this RM. optionally perform a route discovery; by issuing a RREQ with ThisNode
listed as the TargetNode, using the procedure in Section 5.3.1.
Note: it is important that when creating the RREQ, the RREQ
OrigNode.Address for ThisNode be within the same prefix as the RREQ
TargetNode.Address. At this point, ThisNode need not perform any
more operations for the original RM.
If ThisNode is not the TargetNode, this RM is a RREQ, the RREQ If ThisNode is not the TargetNode, this RM is a RREQ, the RREQ
contains the TargetNode.AddTLV.SeqNum, and ThisNode has a forwarding contains the TargetNode.AddTLV.SeqNum, and ThisNode has a forwarding
route to the TargetNode with a SeqNum where Route.TargetNode.SeqNum - route to the TargetNode with a SeqNum where Route.TargetNode.SeqNum -
RREQ.TargetNode.AddTLV.SeqNum >= 0 (using signed 16-bit arithmetic); RREQ.TargetNode.AddTLV.SeqNum >= 0 (using signed 16-bit arithmetic);
then this node MAY respond with an intermediate DYMO router RREP. then this node MAY respond with an intermediate DYMO router RREP.
The procedure for performing intermediate DYMO router RREP is The procedure for performing intermediate DYMO router RREP is
described in Section 5.3.3. At this point, ThisNode need not perform described in Section 5.3.3. If an intermediate DYMO router RREP is
any more operations for this RM. sent, ThisNode need not perform any more operations for the original
RM.
After processing a RM or creating a new RM, a node can append After processing a RM or creating a new RM, a node can append
additional routing information to the RM, according to the procedure additional routing information to the RM, according to the procedure
described in Section 5.3.5. The additional routing information can described in Section 5.3.5. The additional routing information can
help reduce route discoveries at the expense of increased message help reduce route discoveries at the expense of increased message
size. size.
For each address (except the TargetNode) in the RM that includes For each address (except the TargetNode) in the RM that includes
AddTLV.Dist information, the AddTLV.Dist information is incremented AddTLV.Dist information, the AddTLV.Dist information is incremented
by a cost value. Advice regarding the cost value is not included in by at least one (1). The updated distance value will influence
this specification, it is left up to the implementation. judgment of the routing information (Section 5.2.1) against known
information at other DYMO routers that process this RM.
The updated distance value will be an measure in determining whether
the routing information is inferior or superior to known information
at other DYMO routers that process this RM.
If the resulting distance value for the OrigNode is greater than If the resulting distance value for the OrigNode is greater than
65,535, the message is discarded. If the resulting distance value 65,535, the message is discarded. If the resulting distance value
for another node is greater than 65,535, the associated address and for another node is greater than 65,535, the associated address and
its information are removed from the RM. its information are removed from the RM.
If this RM's MsgHdr.HopLimit is greater than or equal to one (1), Next, the MsgHdr.HopLimit is decremented by one (1). If this RM's
ThisNode is not the TargetNode, AND this RM is a RREQ, then the MsgHdr.HopLimit is greater than or equal to one (1), ThisNode is not
current RM (altered by the procedure defined above) SHOULD be sent to the TargetNode, AND this RM is a RREQ, then the current RM (altered
the LL MANET ROUTERS IP.DestinationAddress. by the procedure defined above) SHOULD be sent to the
IP.DestinationAddress LL-MANET-ROUTERS [I-D.ietf-manet-iana].
By sending the RM ThisNode is advertising that it will provide
routing for IP addresses contained in the outgoing RM based on the
information enclosed. ThisNode MAY choose not to send the RM, though
not resending this RM could decrease connectivity in the network or
result in a non-shortest distance path.
Some examples of why ThisNode might choose to not send the RM are: if
ThisNode does not want to advertise routing for the contained IP
addresses because it is already congested; if ThisNode has already
issued nearly identical routing information (e.g. ThisNode had
recently issued a RM with nearly the same distance); or if ThisNode
is low on energy and does not want to expend energy for control
message sending or packet forwarding. This type of advanced behavior
is not defined in this specification.
If this RM's MsgHdr.HopLimit is greater than or equal to one (1), If this RM's MsgHdr.HopLimit is greater than or equal to one (1),
ThisNode is not the TargetNode, AND this RM is a RREP, then the ThisNode is not the TargetNode, AND this RM is a RREP, then the
current RM is sent to the Route.NextHopAddress for the RREP's current RM is sent to the Route.NextHopAddress for the RREP's
TargetNode.Address. If no forwarding route exists to Target.Address, TargetNode.Address. If no forwarding route exists to Target.Address,
then a RERR is issued to the OrigNode of the RREP. then a RERR is issued to the OrigNode of the RREP.
By sending the updated RM ThisNode is advertising that it will
provide routing for IP addresses contained in the outgoing RM based
on the information enclosed. ThisNode MAY choose not to send the RM,
though not resending this RM could decrease connectivity in the
network or result in a non-shortest distance path.
Some examples of why ThisNode might choose to not re-issue a RM are:
if ThisNode does not want to advertise routing for the contained IP
addresses because it is already heavily loaded; if ThisNode has
already issued nearly identical routing information (e.g. ThisNode
had recently issued a RM with nearly the same distance); or if
ThisNode is low on energy and does not want to expend energy for
control message sending or packet forwarding. This type of advanced
behavior is not defined in this specification.
5.3.5. Adding Additional Routing Information to a RM 5.3.5. Adding Additional Routing Information to a RM
Appending routing information can alleviate route discovery attempts Appending routing information can alleviate route discovery attempts
to the nodes whose information is included, if other DYMO routers use to the nodes whose information is included, if other DYMO routers use
this information to update their routing tables. this information to update their routing tables.
DYMO routers can append routing information to a RM. This option DYMO routers can append routing information to a RM. This option
should be administratively configurable. should be administratively configurable or intelligently controlled.
Prior to appending an address controlled by this DYMO router to a RM, Prior to appending an address controlled by this DYMO router to a RM,
ThisNode MAY increment its OwnSeqNum as defined in Section 5.1.2. If ThisNode MAY increment its OwnSeqNum as defined in Section 5.1.2. If
OwnSeqNum is not incremented the appended routing information might OwnSeqNum is not incremented the appended routing information might
not be considered fresh, when received by nodes with existing routing not be considered superior, when received by nodes with existing
information. Incrementation of the sequence number when appending routing information. Incrementation of the sequence number when
information to an RM in transit should be administratively appending information to an RM in transit should be administratively
configurable. configurable or intelligently controlled.
If an address controlled by this DYMO router includes ThisNode.Dist, If an address controlled by this DYMO router includes ThisNode.Dist,
it is set to a number greater than zero (0). it is set to a number greater than zero (0).
For added addresses not controlled by this DYMO router, Route.Dist For added addresses (and their prefixes) not controlled by this DYMO
can be included if known. If Route.Dist is not known, it cannot be router, Route.Dist can be included if known. If Route.Dist is not
included. known, it MUST NOT be included.
Additional information about the appended address(es) can also be MaxAge information about the appended address(es) MUST be included.
included (e.g. Prefix).
Additional information (e.g. SeqNum and Dist) about any appended
address(es) SHOULD be included.
Note that, the routing information about the TargetNode MUST NOT be
added. Also, duplicate address entries SHOULD NOT be added.
Instead, only the best routing information (Section 5.2.1) for a
particular address SHOULD be included.
5.4. Route Discovery 5.4. Route Discovery
When a source's DYMO router needs to forward a data packet and it When a source's DYMO router needs to forward a data packet on behalf
does not have a forwarding route to the IP.DestinationAddress, it of an attached node and it does not have a forwarding route to the
sends a RREQ (described in Section 5.3.1) to discover a route to the data packet's unicast IP destination address, ThisNode sends a RREQ
particular destination (TargetNode). (described in Section 5.3.1) to discover a route to the particular
destination (TargetNode).
After issuing a RREQ, the OrigNode DYMO router waits for a route to After issuing a RREQ, the OrigNode DYMO router waits for a route to
be created to the TargetNode. If a route is not created within be created to the TargetNode. If a route is not created within
RREQ_WAIT_TIME, ThisNode may again try to discover a route by issuing RREQ_WAIT_TIME, ThisNode may again try to discover a route by issuing
another RREQ using the procedure defined in Section 5.3.1. another RREQ using the procedure defined in Section 5.3.1 again.
To reduce congestion in a network, repeated attempts at route To reduce congestion in a network, repeated attempts at route
discovery for a particular TargetNode should utilize an exponential discovery for a particular TargetNode SHOULD utilize an exponential
backoff. backoff.
For example, the first time a DYMO router issues a RREQ, it waits For example, the first time a DYMO router issues a RREQ, it waits
RREQ_WAIT_TIME for a route to the TargetNode. If a route is not RREQ_WAIT_TIME for a route to the TargetNode. If a route is not
found within that time, the DYMO router MAY send another RREQ. If a found within that time, the DYMO router MAY send another RREQ. If a
route is not found within two (2) times the current waiting time, route is not found within two (2) times the current waiting time,
another RREQ may be sent, up to a total of RREQ_TRIES. For each another RREQ may be sent, up to a total of RREQ_TRIES. For each
additional attempt, the waiting time for the previous RREQ is additional attempt, the waiting time for the previous RREQ is
multiplied by two (2) so that the waiting time conforms to a binary multiplied by two (2) so that the waiting time conforms to a binary
exponential backoff. exponential backoff.
Data packets awaiting a route should be buffered by the source's DYMO Data packets awaiting a route SHOULD be buffered by the source's DYMO
router. This buffer should have a fixed limited size router. This buffer SHOULD have a fixed limited size
(BUFFER_SIZE_PACKETS or BUFFER_SIZE_BYTES) and older data packets (BUFFER_SIZE_PACKETS or BUFFER_SIZE_BYTES) and older data packets
SHOULD be discarded first. SHOULD be discarded first.
Buffering of data packets may have positive or negative impact, and Buffering of data packets can have both positive and negative
therefore must be administratively configurable. effects, and therefore buffer settings SHOULD be administratively
configurable or intelligently controlled.
If a route discovery has been attempted RREQ_TRIES times without If a route discovery has been attempted RREQ_TRIES times without
receiving a route to the TargetNode, all data packets destined for receiving a route to the TargetNode, all data packets destined for
the corresponding TargetNode are dropped from the buffer and a the corresponding TargetNode are dropped from the buffer and a
Destination Unreachable ICMP message should be delivered to the Destination Unreachable ICMP message should be delivered to the
source. source.
5.5. Route Maintenance 5.5. Route Maintenance
A RERR MUST be issued if a data packet is to be forwarded and it A RERR SHOULD be issued if a data packet is to be forwarded and it
cannot be delivered to the next hop because no forwarding route for cannot be delivered to the next hop because no forwarding route for
the IP.Destination exists; RERR generation is described in the IP.DestinationAddress exists; RERR generation is described in
Section 5.5.3. Section 5.5.3.
Upon this condition, an ICMP Destination Unreachable message SHOULD Upon this condition, an ICMP Destination Unreachable message SHOULD
NOT be generated unless this router is responsible for the NOT be generated unless this router is responsible for the
IP.Destination and that IP.Destination is known to be unreachable. IP.DestinationAddress and that IP.DestinationAddress is known to be
unreachable.
In addition to inability to forward a data packet, a RERR SHOULD be In addition to inability to forward a data packet, a RERR SHOULD be
issued immediately after detecting a broken link of an forwarding issued immediately after detecting a broken link of an forwarding
route to quickly notify DYMO routers that a link break occurred and route to quickly notify DYMO routers that a link break occurred and
that certain routes are no longer available. If the route with the that certain routes are no longer available. If the route with the
broken link has not been used recently (indicated by ROUTE_USED), the broken link has not been used recently (indicated by ROUTE_USED), the
RERR SHOULD NOT be generated. RERR SHOULD NOT be generated.
5.5.1. Active Link Monitoring 5.5.1. Active Link Monitoring
skipping to change at page 26, line 20 skipping to change at page 26, line 22
including: including:
o Link layer feedback o Link layer feedback
o Neighborhood discovery [I-D.ietf-manet-nhdp] o Neighborhood discovery [I-D.ietf-manet-nhdp]
o Route timeout o Route timeout
o Other monitoring mechanisms or heuristics o Other monitoring mechanisms or heuristics
Upon detecting a link break (or an unreachable next hop) ThisNode Upon determining that a link is broken (or the next hop is
must remove the affected forwarding routes (those with an unreachable unreachable), ThisNode MUST remove the affected forwarding routes
next hop). ThisNode also flags these routes as Broken. For each (those with an unreachable next hop). ThisNode also flags these
broken route a timer for ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT. routes as Broken. For each broken route a timer for ROUTE_DELETE is
set to ROUTE_DELETE_TIMEOUT.
5.5.2. Updating Route Lifetimes During Packet Forwarding 5.5.2. Updating Route Lifetimes During Packet Forwarding
To avoid removing the forwarding route to reach the IP.SourceAddress, To avoid removing the forwarding route to reach the IP.SourceAddress,
a node SHOULD set a timeout (ROUTE_USED) to ROUTE_USED_TIMEOUT for ThisNode SHOULD set a timeout (ROUTE_USED) to ROUTE_USED_TIMEOUT for
the route to the IP.SourceAddress upon receiving a data packet. If a the route to the IP.SourceAddress upon receiving a data packet. If a
timer for ROUTE_DELETE is set, it is removed. timer for ROUTE_DELETE is set, it is removed.
To avoid removing the forwarding route to the IP.DestinationAddress To avoid removing the forwarding route to the IP.DestinationAddress
that is being used, a node SHOULD set a timeout (ROUTE_USED) to that is being used, ThisNode SHOULD set a timeout (ROUTE_USED) to
ROUTE_USED_TIMEOUT for the route to the IP.DestinationAddress upon ROUTE_USED_TIMEOUT for the route to the IP.DestinationAddress upon
sending a data packet. If a timer for ROUTE_DELETE is set, it is sending a data packet. If a timer for ROUTE_DELETE is set, it is
removed. removed.
5.5.3. Route Error Generation 5.5.3. Route Error Generation
A RERR informs DYMO routers that a route to certain destinations is A RERR informs DYMO routers that a route to certain destinations is
not available through this node. not available through ThisNode.
When creating a new RERR, the address of first UnreachableNode When creating a new RERR, the address of first UnreachableNode
(IP.DestinationAddress from a data packet or RREP.TargetNode.Address) (IP.DestinationAddress from a data packet or RREP.TargetNode.Address)
is inserted into an Address Block AddBlk.UnreachableNode.Address. If is inserted into an Address Block AddBlk.UnreachableNode.Address. If
a value for the UnreachableNode's SeqNum a prefix is known for the UnreachableNode.Address, it SHOULD be
(UnreachableNode.AddTLV.SeqNum) is known, it SHOULD be placed in the included. Otherwise, the UnreachableNode.Address assumed to be a
RERR. The MsgHdr.HopLimit is set to MAX_HOPLIMIT. host address with a full length prefix. If a value for the
UnreachableNode's SeqNum (UnreachableNode.AddTLV.SeqNum) is known, it
SHOULD be placed in the RERR. The MsgHdr.HopLimit is set to
MAX_HOPLIMIT.
Additional UnreachableNodes that require the same unavailable link Additional UnreachableNodes that require the same unavailable link
(routes with the same Route.NextHopAddress and (routes with the same Route.NextHopAddress and
Route.NextHopInterface) SHOULD be added to the RERR, as additional Route.NextHopInterface) SHOULD be added to the RERR, as additional
AddBlk.UnreachableNode.Address. The SeqNum if known SHOULD also be AddBlk.UnreachableNode.Address entries with their associated prefix.
included. Appending UnreachableNode information notifies each The SeqNum if known SHOULD also be included. Appending
processing node of additional routes that are no longer available. UnreachableNode information notifies each processing node of
This option SHOULD be administratively configurable. additional routes that are no longer available. This option SHOULD
be administratively configurable or intelligently controlled.
If SeqNum information is not known or not included in the RERR, all If SeqNum information is not known or not included in the RERR, all
nodes processing the RERR will assume their routing information nodes processing the RERR will assume their routing information
associated with the UnreachableNode is no longer valid and flags associated with the UnreachableNode is no longer valid and flag those
those routes as broken. routes as broken.
The RERR is sent to the IP.DestinationAddress LL MANET ROUTERS. The RERR is sent to the IP.DestinationAddress LL-MANET-ROUTERS
Sending the RERR to the LL MANET ROUTERS address notifies nearby [I-D.ietf-manet-iana]. Sending the RERR to the LL-MANET-ROUTERS
nodes that might depend on the now broken link. address notifies nearby nodes that might depend on the now broken
link.
The packet or message that forced generation of this RERR is At this point, the packet or message that forced generation of this
discarded. RERR SHOULD be discarded.
5.5.4. RERR Processing 5.5.4. RERR Processing
Before processing a RERR, the DYMO router checks the IP.Destination Before processing a RERR, the DYMO router checks the
to ensure that it is addressed to LL MANET ROUTERS. IP.DestinationAddress to ensure that it is addressed to LL-MANET-
ROUTERS [I-D.ietf-manet-iana].
Upon reception of a RERR the MsgHdr.HopLimit is decremented by one
(1).
When a DYMO router processes a RERR, it processes each When a DYMO router processes a RERR, it processes each
UnreachableNode's information. The processing DYMO router removes UnreachableNode's information. The processing DYMO router removes
the forwarding route, sets the broken flag, and a timer for the forwarding route, sets the broken flag, and a timer for
ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT for each ROUTE_DELETE is set to ROUTE_DELETE_TIMEOUT for each
UnreachableNode.Address found using longest prefix matching that meet UnreachableNode.Address found using longest prefix matching that meet
all of the following conditions: all of the following conditions:
1. The UnreachableNode.Address is a unicast address. 1. The UnreachableNode.Address is a unicast address.
skipping to change at page 27, line 50 skipping to change at page 28, line 10
IP.SourceAddress. IP.SourceAddress.
3. The Route.NextHopInterface is the same as the interface on which 3. The Route.NextHopInterface is the same as the interface on which
the RERR was received. the RERR was received.
4. The Route.SeqNum is zero (0), unknown, OR the 4. The Route.SeqNum is zero (0), unknown, OR the
UnreachableNode.SeqNum is zero (0), unknown, OR Route.SeqNum - UnreachableNode.SeqNum is zero (0), unknown, OR Route.SeqNum -
UnreachableNode.SeqNum <= 0 (using signed 16-bit arithmetic). UnreachableNode.SeqNum <= 0 (using signed 16-bit arithmetic).
During processing if Route.SeqNum is zero (0) or unknown and During processing if Route.SeqNum is zero (0) or unknown and
Unreachable.SeqNum exists in the RERR, then Route.SeqNum can be set Unreachable.SeqNum exists in the RERR, then Route.SeqNum MAY be set
to Unreachable.SeqNum. Setting Route.SeqNum can reduce future RRER to Unreachable.SeqNum. Setting Route.SeqNum can reduce future RRER
processing and forwarding. processing and forwarding.
Each UnreachableNode that did not result in a broken route is removed Each UnreachableNode that did not result in a broken route is removed
from the RERR, since propagation of this information will not result from the RERR, since propagation of this information will not result
in any benefit. Any other information (AddTLVs) associated with the in any benefit. Any other information (AddTLVs) associated with the
removed address(es) is also removed. removed address(es) is also removed.
After processing if Route.SeqNum is known and an Unreachable.SeqNum After processing if Route.SeqNum is known and an Unreachable.SeqNum
is not included in the RERR, then Route.SeqNum (i.e. is not included in the RERR, then Route.SeqNum (i.e.
Unreachable.SeqNum) can be added to the RERR. Including Unreachable.SeqNum) MAY be added to the RERR. Including
Unreachable.SeqNum can reduce future RRER processing and forwarding. Unreachable.SeqNum can reduce future RRER processing and forwarding.
If no UnreachableNode addresses remain in the RERR, no other If no UnreachableNode addresses remain in the RERR, no other
processing is required and the RERR is discarded. processing is required and the RERR is discarded.
If this RERR's MsgHdr.HopLimit is greater than one (1) and at least If processing continues, the MsgHdr.HopLimit is decremented by one
one unreachable node address remains in the RERR, then the updated (1). Further, if this RERR's new MsgHdr.HopLimit is greater than one
RERR is sent to the IP.DestinationAddress LL MANET ROUTERS. (1) and at least one unreachable node address remains in the RERR,
then the updated RERR is sent to the IP.DestinationAddress LL-MANET-
ROUTERS [I-D.ietf-manet-iana].
5.6. Unknown Message & TLV Types 5.6. Unknown Message & TLV Types
If a message with an unknown type is received, the message is If a message with an unknown type is received, the message is
discarded. discarded.
If a message contains TLVs of an unknown type, a node ignores these For processing of messages that contain unknown TLV types, operation
during processing. The processing node can remove these TLVs from should be administratively controlled.
any resulting transmitted messages. The behavior for unknown TLV
types should be administratively configurable.
5.7. Advertising Network Addresses 5.7. Advertising Network Addresses
Any DYMO router advertises a network address by using a PREFIX_LENGTH DYMO routers advertise specify the prefix length for each advertised
TLV [I-D.ietf-manet-packetbb]. Any nodes (other than the advertising address. Any nodes (other than the advertising DYMO router) within
DYMO router) within the advertised prefix SHOULD NOT participate in the advertised prefix MUST NOT participate in the DYMO protocol
the DYMO protocol directly and these nodes MUST be reachable by directly. For example, A.B.C.1 with a prefix length of 24 indicates
forwarding packets to the DYMO router advertising connectivity.
Nodes other than the advertising DYMO router that do participate in
DYMO must forward the DYMO control packets to the advertising DYMO
router. For example, A.B.C.1 with a prefix length of 24 indicates
all nodes with the matching A.B.C.X are reachable through the DYMO all nodes with the matching A.B.C.X are reachable through the DYMO
router with address A.B.C.1. router with address A.B.C.1.
5.8. Simple Internet Attachment and Gatewaying 5.8. Simple Internet Attachment
Simple Internet attachment consists of a stub network of MANET Simple Internet attachment consists of a stub network of MANET
routers connected to the Internet via a single Internet gateway node. routers connected to the Internet via a single Internet DYMO router
DYMO can operate with multiple gateways, but such behavior is not (IDR). The Internet may be connected via multiple DYMO routers, but
specified in this document. such behavior is not specified in this document.
The gateway is responsible for responding to RREQs for TargetNodes The IDR is responsible for responding to RREQs for DYMO routers on
outside its configured DYMO prefix, as well as delivering packets to behalf of TargetNodes on the Internet, as well as delivering packets
destinations outside the MANET. to destinations on the Internet.
/--------------------------\ /--------------------------\
/ Internet \ / Internet \
\ / \ /
\------------+-------------/ \------------+-------------/
Gateway's | |
Advertised | A.B.C.X/24 Routable & |
Topologically | A.B.C.X/24
Correct |
Prefix | Prefix |
+-----+-----+ +-----+-----+
| DYMO | | Internet |
/------| Internet |--------\ /------| DYMO |--------\
/ | Gateway | \ / | Router | \
/ | A.B.C.1 | \ / | A.B.C.1 | \
| +-----------+ | | +-----------+ |
| DYMO Region | | DYMO Region |
| | | |
| +--------------+ | | +--------------+ |
| | DYMO Router | | | | DYMO Router | |
| | A.B.C.2 | | | | A.B.C.2 | |
| +--------------+ | | +--------------+ |
| +--------------+ | | +--------------+ |
| | DYMO Router | | | | DYMO Router | |
| | A.B.C.3 | | | | A.B.C.3 | |
\ +--------------+ / \ +--------------+ /
\ / \ /
\---------------------------/ \---------------------------/
Figure 7: Simple Internet Attachment Example Figure 7: Simple Internet Attachment Example
DYMO routers wishing to be reachable from nodes in the Internet MUST DYMO routers wishing to be reachable from nodes in the Internet MUST
have IP addresses within the gateway's configured and advertised have IP addresses within the IDR's routable and topologically correct
prefix. Given a node with a globally routeable address or care-of prefix. Given a node with a routeable address or care-of address
address handled by the gateway, the gateway is responsible for handled by the IDR, the IDR is responsible for routing and forwarding
routing and forwarding packets received from the Internet destined packets received from the Internet destined for nodes inside its
for nodes inside its MANET. MANET.
When DYMO router within the MANET want to send messages to nodes in When DYMO router within the MANET want to send packets to a node on
the Internet, they simply issue RREQ for those the Internet, they simply issue RREQ for those IP Destination
IP.DestinationAddresses. The gateway is responsible for responding Addresses; using normal DYMO route discovery. The IDR is responsible
to RREQ on behalf of the Internet destinations and maintaining their for properly responding to RREQ on behalf of the Internet
associated sequence number. destinations, and maintaining their associated sequence number(s).
For an Internet gateway and other DYMO routers that maintain the For an IDR and other DYMO routers that maintain the sequence number
sequence number on behalf of other nodes, these routers must be on behalf of other nodes, these routers MUST know the IP addresses
administratively configurable to know the IP addresses for which they for which they MUST generate DYMO messages and maintain OwnSeqNum.
must generate DYMO messages and maintain OwnSeqNum. Likewise, they MUST be capable of advertising an address within the
same prefix as these IP addresses. Alternatively, they may behave as
a proxy on behalf of Internet destinations.
5.9. Multiple Interfaces 5.9. Multiple Interfaces
DYMO may be used with multiple interfaces; therefore, the particular DYMO may be used with multiple interfaces; therefore, the particular
interface over which packets arrive must be known whenever a packet interface over which packets arrive MUST be known whenever a packet
is received. Whenever a new route is created, the interface through is received. Whenever a new route is created, the interface through
which the Route.Address can be reached is also recorded in the route which the Route.Address can be reached is also recorded in the route
table entry. table entry.
When multiple interfaces are available, a node transmitting a packet When multiple interfaces are available, a node transmitting a packet
with IP.DestinationAddress set to LL MANET ROUTERS SHOULD send the with IP.DestinationAddress set to LL-MANET-ROUTERS SHOULD send the
packet on all interfaces that have been configured for DYMO packet on all interfaces that have been configured for DYMO
operation. operation.
Similarly, DYMO routers should subscribe to LL MANET ROUTERS on all Similarly, DYMO routers should subscribe to LL-MANET-ROUTERS on all
their DYMO interfaces. their DYMO interfaces.
5.10. Packet/Message Generation Limits 5.10. DYMO Control Packet/Message Generation Limits
To avoid congestion, a node's rate of packet/message generation To ensure predictable control overhead, DYMO router's rate of packet/
should be limited. The rate and algorithm for limiting messages is message generation SHOULD be limited. The rate and algorithm for
left to the implementor and should be administratively configurable. limiting messages is left to the implementor and should be
Messages should be discarded in the following order of preferences administratively configurable or intelligently controlled. DYMO
RREQ, RREP, and finally RERR. control messages SHOULD be discarded in the following order of
preferences RREQ, RREP, and finally RERR.
6. Configuration Parameters and Other Administrative Options 6. Configuration Parameters and Other Administrative Options
Suggested Parameter Values Suggested Parameter Values
+------------------------------+------------------------+ +------------------------------+-------------------+
| Name | Value | | Name | Value |
+------------------------------+------------------------+ +------------------------------+-------------------+
| MAX_HOPLIMIT | 10 hops | | MAX_HOPLIMIT | 10 hops |
| NET_TRAVERSAL_TIME | 1000 milliseconds |
| ROUTE_TIMEOUT | 5 seconds | | ROUTE_TIMEOUT | 5 seconds |
| ROUTE_AGE_MIN_TIMEOUT | NET_TRAVERSAL_TIME | | ROUTE_AGE_MIN_TIMEOUT | 1 second |
| ROUTE_AGE_MAX_TIMEOUT | 60 seconds | | ROUTE_AGE_MAX_TIMEOUT | 60 seconds |
| ROUTE_NEW_TIMEOUT | ROUTE_TIMEOUT |
| ROUTE_USED_TIMEOUT | ROUTE_TIMEOUT | | ROUTE_USED_TIMEOUT | ROUTE_TIMEOUT |
| ROUTE_DELETE_TIMEOUT | 2 * ROUTE_TIMEOUT | | ROUTE_DELETE_TIMEOUT | 2 * ROUTE_TIMEOUT |
| ROUTE_RREQ_WAIT_TIME | 2 * NET_TRAVERSAL_TIME | | ROUTE_RREQ_WAIT_TIME | 2 seconds |
| RREQ_TRIES | 3 tries | | RREQ_TRIES | 3 tries |
| UNICAST_MESSAGE_SENT_TIMEOUT | 1 second | | UNICAST_MESSAGE_SENT_TIMEOUT | 1 second |
+------------------------------+------------------------+ +------------------------------+-------------------+
Table 2 Table 2
These suggested values work well for small and medium well connected These suggested values work well for small and medium well connected
networks with infrequent topology changes. These parameters should networks with infrequent topology changes. These parameters SHOULD
be administratively configurable for the network where DYMO is used. be administratively configurable for the network where DYMO is used.
Ideally, for networks with frequent topology changes the DYMO Ideally, for networks with frequent topology changes the DYMO
parameters should be adjusted using either experimentally determined parameters should be adjusted using either experimentally determined
values or dynamic adaptation. For example, in networks with values or dynamic adaptation. For example, in networks with
infrequent topology changes ROUTE_USED_TIMEOUT may be set to a much infrequent topology changes ROUTE_USED_TIMEOUT may be set to a much
larger value. larger value.
In addition to the parameters above several administrative options In addition to the parameters above several administrative options
exist. The following table enumerates several of the options and exist. Many of these options can be administratively controlled, but
suggested values. they may be better served by intelligent control. The following
table enumerates several of the options.
Suggested Options Settings Important Settings
+-------------------------------------+----------------------------+ +-----------------------------------------+
| Name | Value | | Name |
+-------------------------------------+----------------------------+ +-----------------------------------------+
| RESPONSIBLE_ADDRESSES | Self or Prefix | | RESPONSIBLE_ADDRESSES |
| DYMO_INTERFACES | User Specified | | DYMO_INTERFACES |
| INCLUDE_INFORMATION | Yes-SeqNum,Dist,Prefix | | UNKNOWN_TLV_TYPE_HANDLING |
| APPEND_ADDRESS | Yes - RREQ & RREP | | ROUTE_DISCOVERY_DATA_PACKET_BUFFER_SIZE |
| APPEND_OWN_ADDRESS_INCREMENT_SEQNUM | Yes for RREQ | +-----------------------------------------+
| GENERATE_RERR_IMMEDIATELY | No |
| RERR_INCLUDE_ALL_UNREACHABLES | Yes |
| UNKNOWN_TYPE_HANDLING | Ignore |
| BUFFER_SIZE_PACKETS | 50 packets |
| BUFFER_SIZE_BYTES | 1500 * BUFFER_SIZE_PACKETS |
+-------------------------------------+----------------------------+
Table 3 Table 3
7. IANA Considerations 7. IANA Considerations
DYMO requires a UDP port number to carry protocol packets - MANET In its default mode of operation, DYMO uses the UDP port MANET
[I-D.ietf-manet-iana]. DYMO also requires the link-local multicast [I-D.ietf-manet-iana] to carry protocol packets. DYMO also uses the
address LL MANET ROUTERS [I-D.ietf-manet-iana]. link-local multicast address LL-MANET-ROUTERS [I-D.ietf-manet-iana].
This section specifies several messages types, message tlv-types, and This section specifies several messages types, message tlv-types, and
address tlv-types. address tlv-types.
Future types will be allocated using standard actions as described in
[RFC2434].
7.1. DYMO Message Type Specification 7.1. DYMO Message Type Specification
DYMO Message Types DYMO Message Types
+------------------------+----------+ +------------------------+----------+
| Name | Type | | Name | Type |
+------------------------+----------+ +------------------------+----------+
| Route Request (RREQ) | 10 - TBD | | Route Request (RREQ) | 10 - TBD |
| Route Reply (RREP) | 11 - TBD | | Route Reply (RREP) | 11 - TBD |
| Route Error (RERR) | 12 - TBD | | Route Error (RERR) | 12 - TBD |
skipping to change at page 32, line 27 skipping to change at page 32, line 36
Table 4 Table 4
7.2. Packet and Message TLV Type Specification 7.2. Packet and Message TLV Type Specification
Packet TLV Types Packet TLV Types
+-------------------+------+--------+-------------------------------+ +-------------------+------+--------+-------------------------------+
| Name | Type | Length | Value | | Name | Type | Length | Value |
+-------------------+------+--------+-------------------------------+ +-------------------+------+--------+-------------------------------+
| Unicast Response | 10 - | 0 | Indicates to the processing | | Unicast Response | 10 - | 0 | Indicates to the processing |
| Request | TBD | | node that the previous hop | | Request | TBD | octets | node that the previous hop |
| | | | (IP.SourceAddress) expects a | | | | | (IP.SourceAddress) expects a |
| | | | unicast message within | | | | | unicast message within |
| | | | UNICAST_MESSAGE_SENT_TIMEOUT. | | | | | UNICAST_MESSAGE_SENT_TIMEOUT. |
| | | | Any unicast packet will serve | | | | | Any unicast packet will serve |
| | | | this purpose, and it MAY be | | | | | this purpose, and it MAY be |
| | | | an ICMP REPLY message. If a | | | | | an ICMP REPLY message. If a |
| | | | message is not sent, then the | | | | | message is not sent, then the |
| | | | previous hop may assume that | | | | | previous hop can assume that |
| | | | the link is unidirectional | | | | | the link is unidirectional |
| | | | and may blacklist the link to | | | | | and MAY blacklist the link to |
| | | | this node. | | | | | this node. |
+-------------------+------+--------+-------------------------------+ +-------------------+------+--------+-------------------------------+
Table 5 Table 5
7.3. Address Block TLV Specification 7.3. Address Block TLV Specification
Address Block TLV Types Address Block TLV Types
+----------------+------+---------+---------------------------------+ +---------------+--------------+--------+---------------------------+
| Name | Type | Length | Value | | Name | Type | Length | Value |
+----------------+------+---------+---------------------------------+ +---------------+--------------+--------+---------------------------+
| DYMOSeqNum | 10 - | 16 bits | The DYMO sequence num | | DYMOSeqNum | 10 - TBD | up to | The DYMO sequence num |
| | TBD | (2 | associated with this address. | | | | 2 | associated with this |
| | | bytes) | The sequence number may be the | | | | octets | address. The sequence |
| | | | last known sequence number. | | | | | number may be the last |
| Distance | 11 - | up to | A metric of the distance | | | | | known sequence number. |
| | TBD | 16 bits | traversed by the information | | Distance | 11 - TBD | up to | A metric of the distance |
| | | (2 | associated with this address. | | | | 2 | traversed by the |
| | | bytes) | | | | | octets | information associated |
| MaxAge | 12 - | | The maximum amount of time that | | | | | with this address. |
| | TBD | | information can be maintained | | VALIDITY_TIME | TBD | | The maximum amount of |
| | | | before being deleted. This TLV | | - AKA MaxAge | [I-D.ietf-ma | | time that information can |
| | | | conforms to | | | n et-timetlv | | be maintained before |
| | | | [I-D.ietf-manet-timetlv] | | | ] | | being deleted. The |
| | | | VALIDITY_TIME TLV, except that | | | | | VALIDITY_TIME TLV is |
| | | | the TLV is attached to | | | | | defined in |
| | | | addresses. | | | | | [I-D.ietf-manet-timetlv]. |
+----------------+------+---------+---------------------------------+ +---------------+--------------+--------+---------------------------+
Table 6 Table 6
8. Security Considerations 8. Security Considerations
Currently, DYMO does not specify any special security measures. Currently, DYMO does not specify any special security measures.
In situations where confidentiality o DYMO messages is important, In situations where confidentiality of DYMO messages is important,
traditional cryptographic techniques can be applied. traditional cryptographic techniques can be applied.
Securing routing information integrity will likely require DYMO Securing routing information integrity will likely require DYMO
routers to authenticate DYMO messages upon reception. Also, since routers to authenticate DYMO messages upon reception. Also, since
routing information is distributed hop-by-hop, DYMO routers will also routing information is distributed hop-by-hop, DYMO routers will also
likely need to authenticate the source of the routing information, likely need to authenticate the source of the routing information,
the source's DYMO router. the source's DYMO router.
Note that is important that any confidentiality and integrity Note that is important that any confidentiality and integrity
algorithms used permit multiple receivers to process the message, algorithms used permit multiple receivers to process the message,
since all DYMO messaging is multicast. since much of DYMO's messaging is multicast.
9. Acknowledgments 9. Acknowledgments
DYMO is a descendant of the design of previous MANET reactive DYMO is a descendant of the design of previous MANET reactive
protocols, especially AODV [RFC3561] and DSR [RFC4728]. Changes to protocols, especially AODV [RFC3561] and DSR [RFC4728]. Changes to
previous MANET reactive protocols stem from research and previous MANET reactive protocols stem from research and
implementation experiences. Thanks to Elizabeth Belding-Royer for implementation experiences. Thanks to Elizabeth Belding-Royer for
her long time authorship of DYMO. Additional thanks to Luke Klein- her long time authorship of DYMO. Additional thanks to Luke Klein-
Berndt, Pedro Ruiz, Fransisco Ros, Koojana Kuladinithi, Ramon Berndt, Pedro Ruiz, Fransisco Ros, Koojana Kuladinithi, Ramon
Caceres, Thomas Clausen, Christopher Dearlove, Seung Yi, Romain Caceres, Thomas Clausen, Christopher Dearlove, Seung Yi, Romain
Thouvenin, Tronje Krop, Henner Jakob, Alexandru Petrescu, Christoph Thouvenin, Tronje Krop, Henner Jakob, Alexandru Petrescu, Christoph
Sommer, Cong Yuan, and Lars Kristensen for reviewing of DYMO, as well Sommer, Cong Yuan, and Lars Kristensen for reviewing of DYMO, as well
as several specification suggestions. as several specification suggestions.
10. References 10. References
10.1. Normative References 10.1. Normative References
[I-D.ietf-manet-iana] [I-D.ietf-manet-iana]
Chakeres, I., "IANA Allocations for Mobile Ad hoc Network Chakeres, I., "IANA Allocations for MANET Protocols",
(MANET) Protocols", draft-ietf-manet-iana-06 (work in draft-ietf-manet-iana-07 (work in progress),
progress), October 2007. November 2007.
[I-D.ietf-manet-packetbb] [I-D.ietf-manet-packetbb]
Clausen, T., "Generalized MANET Packet/Message Format", Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
draft-ietf-manet-packetbb-10 (work in progress), "Generalized MANET Packet/Message Format",
October 2007. draft-ietf-manet-packetbb-11 (work in progress),
November 2007.
[I-D.ietf-manet-timetlv] [I-D.ietf-manet-timetlv]
Clausen, T. and C. Dearlove, "Representing multi-value Clausen, T. and C. Dearlove, "Representing multi-value
time in MANETs", draft-ietf-manet-timetlv-02 (work in time in MANETs", draft-ietf-manet-timetlv-04 (work in
progress), August 2007. progress), November 2007.
[RFC1812] Baker, F., "Requirements for IP Version 4 Routers", [RFC1812] Baker, F., "Requirements for IP Version 4 Routers",
RFC 1812, June 1995. RFC 1812, June 1995.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., and C.
IANA Considerations Section in RFCs", BCP 26, RFC 2434, Pignataro, "The Generalized TTL Security Mechanism
October 1998. (GTSM)", RFC 5082, October 2007.
10.2. Informative References 10.2. Informative References
[I-D.ietf-manet-jitter] [I-D.ietf-manet-jitter]
Clausen, T., "Jitter considerations in MANETs", Clausen, T., Dearlove, C., and B. Adamson, "Jitter
draft-ietf-manet-jitter-02 (work in progress), considerations in Mobile Ad Hoc Networks (MANETs)",
August 2007. draft-ietf-manet-jitter-04 (work in progress),
December 2007.
[I-D.ietf-manet-nhdp] [I-D.ietf-manet-nhdp]
Clausen, T., "MANET Neighborhood Discovery Protocol Clausen, T., Dearlove, C., and J. Dean, "MANET
(NHDP)", draft-ietf-manet-nhdp-04 (work in progress), Neighborhood Discovery Protocol (NHDP)",
July 2007. draft-ietf-manet-nhdp-05 (work in progress),
December 2007.
[Perkins99] [Perkins99]
Perkins, C. and E. Belding-Royer, "Ad hoc On-Demand Perkins, C. and E. Belding-Royer, "Ad hoc On-Demand
Distance Vector (AODV) Routing", Proceedings of the 2nd Distance Vector (AODV) Routing", Proceedings of the 2nd
IEEE Workshop on Mobile Computing Systems and IEEE Workshop on Mobile Computing Systems and
Applications, New Orleans, LA, pp. 90-100, Applications, New Orleans, LA, pp. 90-100,
February 1999. February 1999.
[RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On- [RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On-
Demand Distance Vector (AODV) Routing", RFC 3561, Demand Distance Vector (AODV) Routing", RFC 3561,
skipping to change at page 35, line 37 skipping to change at page 35, line 40
Ian D Chakeres Ian D Chakeres
Motorola Motorola
Bangalore Bangalore
India India
Email: ian.chakeres@gmail.com Email: ian.chakeres@gmail.com
URI: http://www.ianchak.com/ URI: http://www.ianchak.com/
Charles E. Perkins Charles E. Perkins
Palo Alto Systems Research Center Palo Alto, CA
975 Page Mill Road, Suite 200
Palo Alto, CA 94304-1003
USA USA
Phone: +1-650-496-4402 Email: charliep@computer.org
Fax: +1-650-739-0779
Email: charles.perkins@nokia.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
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