draft-ietf-ospf-manet-single-hop-or-01.txt   draft-ietf-ospf-manet-single-hop-or-02.txt 
Network Working Group A. Retana Network Working Group A. Retana
Internet-Draft S. Ratliff Internet-Draft S. Ratliff
Updates: 5820 (if approved) Cisco Systems, Inc. Updates: 5820 (if approved) Cisco Systems, Inc.
Intended status: Experimental February 25, 2013 Intended status: Experimental May 13, 2013
Expires: August 29, 2013 Expires: November 14, 2013
Use of the OSPF-MANET Interface in Single-Hop Broadcast Networks Use of the OSPF-MANET Interface in Single-Hop Broadcast Networks
draft-ietf-ospf-manet-single-hop-or-01 draft-ietf-ospf-manet-single-hop-or-02
Abstract Abstract
This document describes the use of the OSPF-MANET interface in This document describes the use of the OSPF-MANET interface in
single-hop broadcast networks. It includes a mechanism to single-hop broadcast networks. It includes a mechanism to
dynamically determine the presence of such a network and specific dynamically determine the presence of such a network and specific
operational considerations due to its nature. operational considerations due to its nature.
Status of this Memo This document updates [RFC5820].
Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 29, 2013. This Internet-Draft will expire on November 14, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Single-Hop Broadcast Networks . . . . . . . . . . . . . . . 3 1.1. Single-Hop Broadcast Networks . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . . 4 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Single-Hop Network Operation . . . . . . . . . . . . . . . . . 4 3. Single-Hop Network Operation . . . . . . . . . . . . . . . . 3
3.1. Use of Router Priority . . . . . . . . . . . . . . . . . . 4 3.1. Use of Router Priority . . . . . . . . . . . . . . . . . 4
3.2. Unsynchronized Adjacencies . . . . . . . . . . . . . . . . 5 3.2. Unsynchronized Adjacencies . . . . . . . . . . . . . . . 5
4. Single-Hop Network Detection . . . . . . . . . . . . . . . . . 6 4. Single-Hop Network Detection . . . . . . . . . . . . . . . . 5
4.1. Transition from multi-hop to single-hop mode . . . . . . . 6 4.1. Transition from multi-hop to single-hop mode . . . . . . 6
4.2. Transition from single-hop to multi-hop mode . . . . . . . 7 4.2. Transition from single-hop to multi-hop mode . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 8 8.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . . 8 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 8
A.1. Changes between the -00 and -01 versions. . . . . . . . . . 8 A.1. Changes between the -00 and -01 versions. . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 A.2. Changes between the -01 and -02 versions. . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
The OSPF-MANET interface [RFC5820] uses the point-to-multipoint The OSPF-MANET interface [RFC5820] uses the point-to-multipoint
adjacency model over a broadcast media to allow the following: adjacency model over a broadcast media to allow the following:
o all router-to-router connections are treated as if they were o all router-to-router connections are treated as if they were
point-to-point links. point-to-point links.
o Link metric can be set on a per-neighbor basis. o Link metric can be set on a per-neighbor basis.
o Broadcast and multicast can be accomplished through the Layer 2 o Broadcast and multicast can be accomplished through the Layer 2
broadcast capabilities of the media. broadcast capabilities of the media.
It is clear that the characteristics of the MANET interface can also It is clear that the characteristics of the MANET interface can also
be beneficial in other types of network deployments; specifically in be beneficial in other types of network deployments; specifically in
single-hop broadcast capable networks which may have a different cost single-hop broadcast capable networks which may have a different cost
associated with any pair of nodes. associated with any pair of nodes.
This document describes the use of the MANET interface in single-hop This document updates [RFC5820] by describing the use of the MANET
broadcast networks. interface in single-hop broadcast networks.
1.1. Single-Hop Broadcast Networks 1.1. Single-Hop Broadcast Networks
The OSPF extensions for MANET networks assume the ad-hoc formation of The OSPF extensions for MANET networks assume the ad-hoc formation of
a network over bandwidth-constrained wireless links, where packets a network over bandwidth-constrained wireless links, where packets
may traverse several intermediate nodes before reaching their may traverse several intermediate nodes before reaching their
destination (multi-hop paths on the interface). By contrast, a destination (multi-hop paths on the interface). By contrast, a
single-hop broadcast network (as considered in this document) is one single-hop broadcast network (as considered in this document) is one
that is structured in such a way that all the nodes in it are that is structured in such a way that all the nodes in it are
directly connected to each other. An Ethernet interface is a good directly connected to each other. An Ethernet interface is a good
example of the connectivity model. example of the connectivity model.
Furthermore, the single-hop networks considered may have different Furthermore, the single-hop networks considered may have different
skipping to change at page 4, line 29 skipping to change at page 4, line 11
This document describes the use of already defined mechanisms and This document describes the use of already defined mechanisms and
requires no additional on-the-wire changes. requires no additional on-the-wire changes.
3.1. Use of Router Priority 3.1. Use of Router Priority
Smart Peering [RFC5820] can be used to reduce the burden of requiring Smart Peering [RFC5820] can be used to reduce the burden of requiring
a full mesh of adjacencies. In short, a new adjacency is not a full mesh of adjacencies. In short, a new adjacency is not
required if reachability to the node is already available through the required if reachability to the node is already available through the
existing SPT. In general, the reachability is verified on a first- existing SPT. In general, the reachability is verified on a first-
come-first-served basis; i.e. in a typical network, the neighbors come-first-served basis; i.e. in a typical network, the neighbors
with which a FULL adjacency is set up depend on the order of with which a FULL adjacency is set up depend on the order of
discovery. discovery.
The Smart Peering state machine allows for the definition of The Smart Peering state machine allows for the definition of
heuristics, beyond the SPT reachability, to decide whether or not it heuristics, beyond the SPT reachability, to decide whether or not it
considers a new adjacency to be of value. This section describes one considers a new adjacency to be of value. This section describes one
such heuristic to be used in Step (3) of the state machine, in place such heuristic to be used in Step (3) of the state machine, in place
of the original one. of the original one.
The Router Priority (as defined in OSPFv2 [RFC2328] and OSPFv3 The Router Priority (as defined in OSPFv2 [RFC2328] and OSPFv3
skipping to change at page 5, line 9 skipping to change at page 5, line 5
Router Priority Router Priority
An 8-bit unsigned integer. Used to determine the precedence of An 8-bit unsigned integer. Used to determine the precedence of
which router(s) to establish a FULL adjacency with during the which router(s) to establish a FULL adjacency with during the
Smart Peering selection process. When more than one router Smart Peering selection process. When more than one router
attached to a network is present, the one with the highest attached to a network is present, the one with the highest
Router Priority takes precedence. If there is still a tie, the Router Priority takes precedence. If there is still a tie, the
router with the highest Router ID takes precedence. router with the highest Router ID takes precedence.
The heuristic for the smart peering state machine is described as: The heuristic for the smart peering state machine is described as:
(3) | (3) |
,'''''''''''''''''''''''''''''''''''''''''''''''''''''''''| ,'''''''''''''''''''''''''''''''''''''''''''''''''''''''''|
| ............................ | | ............................ |
| |Determine if the number of| | | |Determine if the number of| |
| |existing adjacencies is < | | | |existing adjacencies is < | |
| |the maximum configured | | | |the maximum configured | |
| |value | | | |value | |
| '`'''''''\'''''''''''''''/'' | | '`'''''''\'''''''''''''''/'' |
| \ / | | \ / |
| ................\.........../.............. | | ................\.........../.............. |
| |Determine if the neighbor has the highest| | | |Determine if the neighbor has the highest| |
| |(Router Priority, Router ID) combination | | | |(Router Priority, Router ID) combination | |
| ''''''''''''`'''/'''''''\'''''''''''''''''' | | ''''''''''''`'''/'''''''\'''''''''''''''''' |
| / \ | | / \ |
'`'''''''''''''''''''''/'''''''''''\''''''''''''''''''''''' '`'''''''''''''''''''''/'''''''''''\'''''''''''''''''''''''
Smart Peering Algorithm Smart Peering Algorithm
In order to avoid churn in the selection and establishment of the In order to avoid churn in the selection and establishment of the
adjacencies, every router SHOULD wait until the ModeChange timer adjacencies, every router SHOULD wait until the ModeChange timer
(Section 4) expires before running the Smart Peering state machine. (Section 4) expires before running the Smart Peering state machine.
Note that this wait should cause the selection process to consider Note that this wait should cause the selection process to consider
all the nodes on the link, instead of being triggered based on all the nodes on the link, instead of being triggered based on
receiving a Hello message from a potential neighbor. The nodes receiving a Hello message from a potential neighbor. The nodes
selected using this process are referred to simply as Smart Peers. selected using this process are referred to simply as Smart Peers.
skipping to change at page 6, line 7 skipping to change at page 6, line 4
advertized as FULL by at least one Smart Peer. advertized as FULL by at least one Smart Peer.
The single-hop nature of the interface allows then the advertisement The single-hop nature of the interface allows then the advertisement
of the reachable adjacencies as FULL without additional signaling. of the reachable adjacencies as FULL without additional signaling.
Flooding SHOULD be enabled for all the unsynchronized adjacencies to Flooding SHOULD be enabled for all the unsynchronized adjacencies to
take advantage of the broadcast nature of the media. As a result, take advantage of the broadcast nature of the media. As a result,
all the nodes in the interface will be able to use all the LSAs all the nodes in the interface will be able to use all the LSAs
received. received.
4. Single-Hop Network Detection 4. Single-Hop Network Detection
A single-hop network is one in which all the nodes are directly A single-hop network is one in which all the nodes are directly
connected. Detection of such an interface can be easily done at connected. Detection of such an interface can be easily done at
every node by comparing the speaker's 1-hop neighbors with its 2-hop every node by comparing the speaker's 1-hop neighbors with its 2-hop
neighborhood. If for every 1-hop neighbor, the set of 2-hop neighborhood. If for every 1-hop neighbor, the set of 2-hop
neighbors corresponds to the set of the remaining 1-hop neighbors, neighbors contains the whole set of the remaining 1-hop neighbors,
then the interface is a single-hop network; this condition is called then the interface is a single-hop network; this condition is called
the Single-Hop Condition. the Single-Hop Condition.
A new field is introduced in the MANET interface data structure. The A new field is introduced in the MANET interface data structure. The
name of the field is SingleHop, and it is a flag indicating that the name of the field is SingleHop, and it is a flag indicating whether
interface MAY operate in single-hop mode (as described in Section 3). the interface is operating in single-hop mode (as described in
The SingleHop flag is set when the node meets the Single-Hop Section 3). The SingleHop flag is set when the node meets the
Condition on the interface. If the Single-Hop Condition is no longer Single-Hop Condition on the interface. If the Single-Hop Condition
met then the SingleHop flag MUST be cleared. is no longer met then the SingleHop flag MUST be cleared.
A new timer is introduced to guide the transition of the interface A new timer is introduced to guide the transition of the interface
from/to multi-hop mode (which is the default mode described in from/to multi-hop mode (which is the default mode described in
[RFC5820]) to/from single-hop mode: [RFC5820]) to/from single-hop mode:
o ModeChange: Every time a node changes the state of the SingleHop o ModeChange: Every time a node changes the state of the SingleHop
flag for the interface, the corresponding ModeChange timer MUST be flag for the interface, the corresponding ModeChange timer MUST be
set. The ModeChange timer represents the length of time in set. The ModeChange timer represents the length of time in
seconds that an interface SHOULD wait before changing between seconds that an interface SHOULD wait before changing between
multi-hop and single-hop modes. It is RECOMMENDED that this timer multi-hop and single-hop modes. It is RECOMMENDED that this timer
skipping to change at page 8, line 4 skipping to change at page 7, line 39
No new security concerns beyond the ones expressed in [RFC5820] are No new security concerns beyond the ones expressed in [RFC5820] are
introduced in this document. introduced in this document.
7. Acknowledgements 7. Acknowledgements
The authors would like to thank Anton Smirnov, Jeffrey Zhang, Alia The authors would like to thank Anton Smirnov, Jeffrey Zhang, Alia
Atlas, Juan Antonio Cordero and Richard Ogier for their comments. Atlas, Juan Antonio Cordero and Richard Ogier for their comments.
8. References 8. References
8.1. Normative References 8.1. Normative References
[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.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC5820] Roy, A. and M. Chandra, "Extensions to OSPF to Support
Mobile Ad Hoc Networking", RFC 5820, March 2010.
8.2. Informative References 8.2. Informative References
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, July 2008. for IPv6", RFC 5340, July 2008.
[RFC5820] Roy, A. and M. Chandra, "Extensions to OSPF to Support
Mobile Ad Hoc Networking", RFC 5820, March 2010.
Appendix A. Change Log Appendix A. Change Log
A.1. Changes between the -00 and -01 versions. A.1. Changes between the -00 and -01 versions.
o Updated contact information. o Updated contact information.
A.2. Changes between the -01 and -02 versions.
o Indicated the nature of the RFC5820 update.
o Clarified the Single-Hop Condition and the SingleHop flag.
o Reshuffled the references.
Authors' Addresses Authors' Addresses
Alvaro Retana Alvaro Retana
Cisco Systems, Inc. Cisco Systems, Inc.
7025 Kit Creek Rd. 7025 Kit Creek Rd.
Research Triangle Park, NC 27709 Research Triangle Park, NC 27709
USA USA
Email: aretana@cisco.com Email: aretana@cisco.com
 End of changes. 16 change blocks. 
52 lines changed or deleted 62 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/