draft-ietf-mpls-tp-requirements-01.txt   draft-ietf-mpls-tp-requirements-02.txt 
Network Working Group B. Niven-Jenkins, Ed. Network Working Group B. Niven-Jenkins, Ed.
Internet-Draft BT Internet-Draft BT
Intended status: Informational D. Brungard, Ed. Intended status: Informational D. Brungard, Ed.
Expires: June 15, 2009 AT&T Expires: July 7, 2009 AT&T
M. Betts, Ed. M. Betts, Ed.
Nortel Networks Nortel Networks
N. Sprecher N. Sprecher
Nokia Siemens Networks Nokia Siemens Networks
S. Ueno S. Ueno
NTT NTT
December 12, 2008 January 3, 2009
MPLS-TP Requirements MPLS-TP Requirements
draft-ietf-mpls-tp-requirements-01 draft-ietf-mpls-tp-requirements-02
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any This Internet-Draft is submitted to IETF in full conformance with the
applicable patent or other IPR claims of which he or she is aware provisions of BCP 78 and BCP 79.
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on June 15, 2009. This Internet-Draft will expire on July 7, 2009.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Abstract Abstract
This document specifies the requirements of an MPLS Transport Profile This document specifies the requirements of an MPLS Transport Profile
(MPLS-TP). This document is a product of a joint International (MPLS-TP). This document is a product of a joint International
Telecommunications Union (ITU)-IETF effort to include an MPLS Telecommunications Union (ITU)-IETF effort to include an MPLS
Transport Profile within the IETF MPLS architecture to support the Transport Profile within the IETF MPLS architecture to support the
capabilities and functionalities of a packet transport network as capabilities and functionalities of a packet transport network as
defined by International Telecommunications Union - defined by International Telecommunications Union -
Telecommunications Standardization Sector (ITU-T). Telecommunications Standardization Sector (ITU-T).
skipping to change at page 3, line 8 skipping to change at page 3, line 8
Requirements Language Requirements Language
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 [RFC2119]. document are to be interpreted as described in [RFC2119].
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6
1.2. Transport network overview . . . . . . . . . . . . . . . . 7 1.2. Transport network overview . . . . . . . . . . . . . . . . 7
2. MPLS-TP Requirements . . . . . . . . . . . . . . . . . . . . . 8 2. MPLS-TP Requirements . . . . . . . . . . . . . . . . . . . . . 8
2.1. General requirements . . . . . . . . . . . . . . . . . . . 8 2.1. General requirements . . . . . . . . . . . . . . . . . . . 9
2.2. Layering requirements . . . . . . . . . . . . . . . . . . 10 2.2. Layering requirements . . . . . . . . . . . . . . . . . . 11
2.3. Data plane requirements . . . . . . . . . . . . . . . . . 11 2.3. Data plane requirements . . . . . . . . . . . . . . . . . 11
2.4. Control plane requirements . . . . . . . . . . . . . . . . 12 2.4. Control plane requirements . . . . . . . . . . . . . . . . 12
2.5. Network Management (NM) requirements . . . . . . . . . . . 13 2.5. Network Management (NM) requirements . . . . . . . . . . . 13
2.6. Operation, Administration and Maintenance (OAM) 2.6. Operation, Administration and Maintenance (OAM)
requirements . . . . . . . . . . . . . . . . . . . . . . . 13 requirements . . . . . . . . . . . . . . . . . . . . . . . 14
2.7. Network performance management (PM) requirements . . . . . 13 2.7. Network performance management (PM) requirements . . . . . 14
2.8. Recovery & Survivability requirements . . . . . . . . . . 13 2.8. Recovery & Survivability requirements . . . . . . . . . . 14
2.8.1. Data plane behavior requirements . . . . . . . . . . . 14 2.8.1. Data plane behavior requirements . . . . . . . . . . . 15
2.8.2. Triggers for protection, restoration, and reversion . 16 2.8.2. Triggers for protection, restoration, and reversion . 17
2.8.3. Management plane operation of protection and 2.8.3. Management plane operation of protection and
restoration . . . . . . . . . . . . . . . . . . . . . 16 restoration . . . . . . . . . . . . . . . . . . . . . 17
2.8.4. Control plane and in-band OAM operation of recovery . 17 2.8.4. Control plane and in-band OAM operation of recovery . 18
2.8.5. Topology-specific recovery mechanisms . . . . . . . . 17 2.8.5. Topology-specific recovery mechanisms . . . . . . . . 18
2.9. QoS requirements . . . . . . . . . . . . . . . . . . . . . 21 2.9. QoS requirements . . . . . . . . . . . . . . . . . . . . . 22
2.10. Security requirements . . . . . . . . . . . . . . . . . . 22 2.10. Security requirements . . . . . . . . . . . . . . . . . . 22
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
4. Security Considerations . . . . . . . . . . . . . . . . . . . 22 4. Security Considerations . . . . . . . . . . . . . . . . . . . 23
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 22 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 23
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.1. Normative References . . . . . . . . . . . . . . . . . . . 23 6.1. Normative References . . . . . . . . . . . . . . . . . . . 23
6.2. Informative References . . . . . . . . . . . . . . . . . . 23 6.2. Informative References . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 25
Intellectual Property and Copyright Statements . . . . . . . . . . 26
1. Introduction 1. Introduction
For many years, Synchronous Optical Networking (SONET)/Synchronous For many years, Synchronous Optical Networking (SONET)/Synchronous
Digital hierarchy (SDH) has provided carriers with a high benchmark Digital hierarchy (SDH) has provided carriers with a high benchmark
for reliability and operational simplicity. With the accelerating for reliability and operational simplicity. With the accelerating
growth of packet-based services (such as Ethernet, Voice over IP growth and penetration of:
(VoIP), Layer 2 (L2)/Layer 3 (L3) Virtual Private Networks (VPNs), IP
Television (IPTV), Radio Access Network (RAN) backhauling, etc.), o Packet-based services such as Ethernet, Voice over IP (VoIP),
carriers are in need of capabilities to efficiently support packet- Layer 2 (L2)/Layer 3 (L3) Virtual Private Networks (VPNs), IP
based services on their transport networks. The need to increase Television (IPTV), Radio Access Network (RAN) backhauling, etc.
their revenue while remaining competitive forces operators to look
for the lowest network Total Cost of Ownership (TCO). Investment in o Applications with various bandwidth and QoS requirements.
equipment and facilities (Capital Expenditure (CAPEX)) and
Operational Expenditure (OPEX) should be minimized. Carriers are in need of technologies capable of efficiently
supporting packet-based services and applications on their transport
networks. The need to increase their revenue while remaining
competitive forces operators to look for the lowest network Total
Cost of Ownership (TCO). Investment in equipment and facilities
(Capital Expenditure (CAPEX)) and Operational Expenditure (OPEX)
should be minimized.
Carriers are considering migrating or evolving to packet transport Carriers are considering migrating or evolving to packet transport
networks in order to reduce their costs and to improve their ability networks in order to reduce their costs and to improve their ability
to support services with guaranteed Service Level Agreements (SLAs). to support services with guaranteed Service Level Agreements (SLAs).
For carriers it is important that migrating from SONET/SDH to packet For carriers it is important that migrating from SONET/SDH to packet
transport networks should not involve dramatic changes in network transport networks should not involve dramatic changes in network
operation, should not necessitate extensive retraining, and should operation, should not necessitate extensive retraining, and should
not require major changes to existing work practices. The aim is to not require major changes to existing work practices. The aim is to
preserve the look-and-feel to which carriers have become accustomed preserve the look-and-feel to which carriers have become accustomed
in deploying their SONET/SDH networks, while providing common, multi- in deploying their SONET/SDH networks, while providing common, multi-
layer operations, resiliency, control and management for packet, layer operations, resiliency, control and management for packet,
circuit and lambda transport networks. circuit and lambda transport networks.
Transport carriers require control and deterministic usage of network Transport carriers require control and deterministic usage of network
resources. They need end-to-end control to engineer network paths resources. They need end-to-end control to engineer network paths
and to efficiently utilize network resources. They require and to efficiently utilize network resources. They require
capabilities to support static (Operational Support System (OSS) capabilities to support static (Operations Support System (OSS)
based) or dynamic (control plane) provisioning of deterministic, based) or dynamic (control plane) provisioning of deterministic,
protected and secured services and their associated resources. protected and secured services and their associated resources.
Carriers will still need to cope with legacy networks (which are Carriers will still need to cope with legacy networks (which are
composed of many layers and technologies), thus the packet transport composed of many layers and technologies), thus the packet transport
network should interwork with other packet and transport networks network should interwork with other packet and transport networks
(both horizontally and vertically). Vertical interworking is also (both horizontally and vertically). Vertical interworking is also
known as client/server or network interworking. Horizontal known as client/server or network interworking. Horizontal
interworking is also known as peer-partition or service interworking. interworking is also known as peer-partition or service interworking.
For more details on each type of interworking and some of the issues For more details on each type of interworking and some of the issues
skipping to change at page 6, line 12 skipping to change at page 6, line 22
etc. Examples of such domains include IGP areas and Autonomous etc. Examples of such domains include IGP areas and Autonomous
Systems. Systems.
Layer network: A layer network as defined in G.805 [ITU.G805.2000] Layer network: A layer network as defined in G.805 [ITU.G805.2000]
provides for the transfer of client information and independent provides for the transfer of client information and independent
operations (OAM) of the client OAM. For an explanation of how a operations (OAM) of the client OAM. For an explanation of how a
layer network as described by G.805 relates to the OSI concept of layer network as described by G.805 relates to the OSI concept of
layering see Appendix I of Y.2611 [ITU.Y2611.2006]. layering see Appendix I of Y.2611 [ITU.Y2611.2006].
Link: A link as defined in G.805 [ITU.G805.2000] is used to describe Link: A link as defined in G.805 [ITU.G805.2000] is used to describe
a fixed relationship between two ports. a fixed relationship between two ports within a layer network. A
link is not necessarily a physical link but can also be supported by
a transport path in the server layer (e.g. SONET/SDH, OTN or
MPLS-TP).
Logical Ring: An MPLS-TP logical ring is constructed from a set of Logical Ring: An MPLS-TP logical ring is constructed from a set of
LSRs and logical data links (such as MPLS-TP LSP tunnels or MSPL-TP LSRs and logical data links (such as MPLS-TP LSP tunnels or MSPL-TP
pseudowires) and physical data links that form a ring topology. pseudowires) and physical data links that form a ring topology.
Path: See Transport path. Path: See Transport path.
Physical Ring: An MPLS-TP physical ring is constructed from a set of Physical Ring: An MPLS-TP physical ring is constructed from a set of
LSRs and physical data links that form a ring topology. LSRs and physical data links that form a ring topology.
Ring Topology: In an MPLS-TP ring topology each LSR is connected to Ring Topology: In an MPLS-TP ring topology each LSR is connected to
exactly two other LSRs, each via a single point-to-point exactly two other LSRs, each via a single point-to-point
bidirectional MPLS-TP capable data link. A ring may also be bidirectional MPLS-TP capable data link. A ring may also be
constructed from only two LSRs where there are also exactly two constructed from only two LSRs where there are also exactly two
links. Rings may be connected to other LSRs to form a larger links. Rings may be connected to other LSRs to form a larger
network. Traffic originating or terminating outside the ring may be network. Traffic originating or terminating outside the ring may be
carried over the ring. Client network nodes (such as CEs) may be carried over the ring. Client network nodes (such as CEs) may be
connected directly to an LSR in the ring. connected directly to an LSR in the ring.
Section: A section is a MPLS-TP network server layer which provides Section: A section is a server layer (which may be MPLS-TP or a
for encapsulation and OAM of a MPLS-TP transport path client layer. different technology) which provides for encapsulation and OAM of a
A section layer may provide for aggregation of multiple MPLS-TP MPLS-TP transport path client layer. A section layer may provide for
clients. aggregation of multiple MPLS-TP clients.
Segment: A segment corresponds to part of a path. A segment may be a
single link (hop) within a path, a series of adjacent links (hops)
within a path, or the entire end-to-end-path.
Service layer: A layer network in which transport paths are used to
carry a customer's (individual or bundled) service (may be point-to-
point, point-to-multipoint or multipoint-to-multipoint services).
Span: A span is synonymous with a link. Segment: A segment is a single resource or a set of cross-connected
resources that constitutes part of a path. A segment may be a single
link (hop) within a path, a series of adjacent links (hops) within a
path, or the entire end-to-end-path.
Tandem Connection: A tandem connection corresponds to a segment of a Tandem Connection: A tandem connection is an arbitrary part of a
path. This may be either a segment of an LSP (i.e. a sub-path), or transport path that can be monitored (via OAM) independently from the
one or more segment(s) of a PW. end-to-end monitoring (OAM). It may be a segment or any other
ordered sequence of contiguous links and/or segments of a transport
path.
Transport path: A connection as defined in G.805 [ITU.G805.2000]. A Transport path: A network connection as defined in G.805
Transport path corresponds to an MPLS-TP LSP or to an MPLS-TP LSP and [ITU.G805.2000]. A Transport path corresponds to an MPLS-TP LSP or
its associated PW or PWs (Single Segment or Multi-Segment). to an MPLS-TP LSP and its associated PW or PWs (Single Segment or
Multi-Segment).
Transport path layer: A layer network which provides point-to-point Transport path layer: A layer network which provides point-to-point
or point-to-multipoint transport paths which are used to carry a or point-to-multipoint transport paths which are used to carry a
higher (client) layer network or aggregates of higher (client) layer higher (client) layer network or aggregates of higher (client) layer
networks, for example the network service layer. It provides for networks, for example the transport service layer. It provides for
independent OAM (of the client OAM) in the transport of the clients. independent OAM (of the client OAM) in the transport of the clients.
Transport service layer: A layer network in which transport paths are
used to carry a customer's (individual or bundled) service (may be
point-to-point, point-to-multipoint or multipoint-to-multipoint
services).
Transmission media layer: A layer network which provides sections Transmission media layer: A layer network which provides sections
(two-port point-to-point connections) to carry the aggregate of (two-port point-to-point connections) to carry the aggregate of
network transport path or network service layers on various physical network transport path or network service layers on various physical
media. media.
1.2. Transport network overview 1.2. Transport network overview
The connection (or transport path) service is the basic service The connection (or transport path) service is the basic service
provided by a transport network. The purpose of a transport network provided by a transport network. The purpose of a transport network
is to carry its clients (i.e. the stream of client PDUs or client is to carry its clients (i.e. the stream of client PDUs or client
skipping to change at page 8, line 21 skipping to change at page 8, line 38
may then be aggregated into a connection for transport through the may then be aggregated into a connection for transport through the
network in order to optimize network management. Server layer OAM is network in order to optimize network management. Server layer OAM is
used to monitor the transport integrity of the client layer or client used to monitor the transport integrity of the client layer or client
aggregate. At any hop, the aggregated signals may be further aggregate. At any hop, the aggregated signals may be further
aggregated in lower layer transport network paths for transport aggregated in lower layer transport network paths for transport
across intermediate shared links. The encapsulated client signals across intermediate shared links. The encapsulated client signals
are extracted at the edges of aggregation domains, and are either are extracted at the edges of aggregation domains, and are either
delivered to the client or forwarded to another domain. In the core delivered to the client or forwarded to another domain. In the core
of the network, only the server layer aggregated signals are of the network, only the server layer aggregated signals are
monitored; individual client signals are monitored at the network monitored; individual client signals are monitored at the network
boundary in the client layer network. boundary in the client layer network. Although the connectivity of
the client of the transport path layer may be point-to-point, point-
to-multipoint or multipoint-to-multipoint, the transport path layer
itself only provides point-to-point or point-to-multipoint transport
paths which are used to carry the client.
Quality-of-service mechanisms are required in the packet transport Quality-of-service mechanisms are required in the packet transport
network to ensure the prioritization of critical services, to network to ensure the prioritization of critical services, to
guarantee BW and to control jitter and delay. guarantee BW and to control jitter and delay.
2. MPLS-TP Requirements 2. MPLS-TP Requirements
2.1. General requirements 2.1. General requirements
1 The MPLS-TP data plane MUST be a subset of the MPLS data plane as 1 The MPLS-TP data plane MUST be a subset of the MPLS data plane as
skipping to change at page 9, line 14 skipping to change at page 9, line 34
5 MPLS-TP MUST support traffic engineered point to point (P2P) and 5 MPLS-TP MUST support traffic engineered point to point (P2P) and
point to multipoint (P2MP) transport paths. point to multipoint (P2MP) transport paths.
6 MPLS-TP MUST support the logical separation of the control and 6 MPLS-TP MUST support the logical separation of the control and
management planes from the data plane. management planes from the data plane.
7 MPLS-TP MUST allow the physical separation of the control and 7 MPLS-TP MUST allow the physical separation of the control and
management planes from the data plane. management planes from the data plane.
8 MPLS-TP MUST support static provisioning of transport paths via a 8 MPLS-TP MUST support static provisioning of transport paths via
Network Management System (NMS) or Operational Support Syste an OSS, i.e. via the management plane.
(OSS), i.e. via the management plane.
9 Mechanisms in an MPLS-TP network that satisfy functional 9 Mechanisms in an MPLS-TP network that satisfy functional
requirements that are common to general transport networks (i.e., requirements that are common to general transport networks (i.e.,
independent of technology) SHOULD be manageable in a way that is independent of technology) SHOULD be manageable in a way that is
coherent with the way the equivalent mechanisms are managed in coherent with the way the equivalent mechanisms are managed in
other transport networks. other transport networks.
10 Static provisioning MUST NOT depend on the presence of any 10 Static provisioning MUST NOT depend on the presence of any
element of a control plane. element of a control plane.
11 MPLS-TP MUST support the capability for network operation 11 MPLS-TP MUST support the capability for network operation
(including OAM) via the management plane (without the use of any (including OAM and recovery) via the management plane (without
control plane protocols). the use of any control plane protocols).
12 A solution MUST be provided to support dynamic provisioning of 12 A solution MUST be provided to support dynamic provisioning of
MPLS-TP transport paths via a control plane. MPLS-TP transport paths via a control plane.
13 The MPLS-TP data plane MUST be capable of forwarding data and 13 The MPLS-TP data plane MUST be capable of forwarding data and
taken recovery actions independently of the control or management taken recovery actions independently of the control or management
plane used to operate the MPLS-TP layer network. That is, the plane used to operate the MPLS-TP layer network. That is, the
MPLS-TP data plane MUST continue to operate normally if the MPLS-TP data plane MUST continue to operate normally if the
management plane or control plane that configured the transport management plane or control plane that configured the transport
paths fails. paths fails.
14 MPLS-TP MUST support transport paths through multiple homogeneous 14 MPLS-TP SHOULD support mechanisms to avoid or minimize traffic
impact (e.g. packet delay, reordering and loss) during network
reconfiguration.
15 MPLS-TP MUST support transport paths through multiple homogeneous
domains. domains.
15 MPLS-TP MUST NOT dictate the deployment of any particular network 16 MPLS-TP MUST NOT dictate the deployment of any particular network
topology either physical or logical, however: topology either physical or logical, however:
A. It MUST be possible to deploy MPLS-TP in rings. A. It MUST be possible to deploy MPLS-TP in rings.
B. It MUST be possible to deploy MPLS-TP in arbitrarily B. It MUST be possible to deploy MPLS-TP in arbitrarily
interconnected rings with one or two points of interconnected rings with one or two points of
interconnection. interconnection.
C. MPLS-TP MUST support rings of at least 16 nodes in order to C. MPLS-TP MUST support rings of at least 16 nodes in order to
support the upgrade of existing TDM rings to MPLS-TP. support the upgrade of existing TDM rings to MPLS-TP.
skipping to change at page 10, line 18 skipping to change at page 10, line 44
D. It MUST be possible to construct rings from equipment D. It MUST be possible to construct rings from equipment
supplied by different vendors and to interconnect rings made supplied by different vendors and to interconnect rings made
wholly from equipment from different vendors. [Editor's wholly from equipment from different vendors. [Editor's
note: This requirement comes from work provided by ITU-T note: This requirement comes from work provided by ITU-T
Q9/15. Unless someone can provide a reason why this would Q9/15. Unless someone can provide a reason why this would
not be the case we should remove this requirement. It is not be the case we should remove this requirement. It is
equivalent to saying that all correct implementations of equivalent to saying that all correct implementations of
MPLS-TP MUST interwork.] MPLS-TP MUST interwork.]
16 MPLS-TP MUST be able to scale gracefully with growing and 17 MPLS-TP MUST be able to scale gracefully with growing and
increasingly complex network topologies as well as with increasingly complex network topologies as well as with
increasing bandwidth demands, number of customers, and number of increasing bandwidth demands, number of customers, and number of
services. services.
17 MPLS-TP SHOULD support mechanisms to safeguard against the 18 MPLS-TP SHOULD support mechanisms to safeguard against the
provisioning of transport paths which contain forwarding loops. provisioning of transport paths which contain forwarding loops.
2.2. Layering requirements 2.2. Layering requirements
18 An MPLS-TP network MUST be able to support one or more client 19 An MPLS-TP network MUST be able to support one or more client
network layers, and MUST be able to use one or more server network layers, and MUST be able to use one or more server
network layers. network layers.
19 A solution MUST be provided to support the transport of MPLS-TP 20 A solution MUST be provided to support the transport of MPLS-TP
and non MPLS-TP client layer networks over an MPLS-TP layer transport paths over MPLS-TP (MPLS-TP as a client of MPLS-TP)
network.
20 A solution MUST be provided to support the transport of an 21 A generic and extensible solution MUST be provided to support the
MPLS-TP layer network over MPLS-TP and non MPLS-TP server layer transport of any client layer network (e.g. Ethernet, ATM, FR,
networks (such as Ethernet, OTN, etc.) etc.) over an MPLS-TP layer network.
21 In an environment where an MPLS-TP layer network is supporting a 22 A solution MUST be provided to support the transport of MPLS-TP
transport paths over any server layer network (such as Ethernet,
SONET/SDH, OTN, etc.).
23 In an environment where an MPLS-TP layer network is supporting a
client network, and the MPLS-TP layer network is supported by a client network, and the MPLS-TP layer network is supported by a
server layer network then operation of the MPLS-TP layer network server layer network then operation of the MPLS-TP layer network
MUST be possible without any dependencies on the server or client MUST be possible without any dependencies on the server or client
network. network.
22 It MUST be possible to operate the layers of a multi-layer 24 It MUST be possible to operate the layers of a multi-layer
network that includes an MPLS-TP layer autonomously. network that includes an MPLS-TP layer autonomously.
The above are not only technology requirements, but also operational. The above are not only technology requirements, but also operational.
Different administrative groups may be responsible for the same layer Different administrative groups may be responsible for the same layer
network or different layer networks. network or different layer networks.
23 It MUST be possible to hide MPLS-TP layer network addressing and 25 It MUST be possible to hide MPLS-TP layer network addressing and
other information (e.g. topology) from client layers. other information (e.g. topology) from client layers.
2.3. Data plane requirements 2.3. Data plane requirements
24 The identification of each transport path within its aggregate 26 The identification of each transport path within its aggregate
MUST be supported. MUST be supported.
25 A label in a particular section MUST uniquely identify the 27 A label in a particular link MUST uniquely identify the transport
transport path. path within that link.
26 A transport path's source MUST be identifiable at its 28 A transport path's source MUST be identifiable at its destination
destination. within its layer network.
27 MPLS-TP MUST support MPLS labels that are assigned by the 29 MPLS-TP MUST support MPLS labels that are assigned by the
downstream (with respect to data flow) node per [RFC3031] and downstream (with respect to data flow) node per [RFC3031] and
[RFC3473] and MAY support context-specific MPLS labels as defined [RFC3473] and MAY support context-specific MPLS labels as defined
in [RFC5331]. in [RFC5331].
28 It MUST be possible to operate and configure the MPLS-TP data 30 It MUST be possible to operate and configure the MPLS-TP data
(transport) plane without any IP forwarding capability in the (transport) plane without any IP forwarding capability in the
MPLS-TP data plane. MPLS-TP data plane.
29 MPLS-TP MUST support both unidirectional and bidirectional point- 31 MPLS-TP MUST support both unidirectional and bidirectional point-
to-point transport paths. to-point transport paths.
30 An MPLS-TP network MUST require the forward and backward 32 An MPLS-TP network MUST require the forward and backward
directions of a bidirectional transport path to follow the same directions of a bidirectional transport path to follow the same
path at each layer. path at each layer.
31 The intermediate nodes at each layer MUST be aware about the 33 The intermediate nodes at each layer MUST be aware about the
pairing relationship of the forward and the backward directions pairing relationship of the forward and the backward directions
belonging to the same bi-directional transport path. belonging to the same bi-directional transport path.
32 MPLS-TP MAY support transport paths with asymmetric bandwidth 34 MPLS-TP MAY support transport paths with asymmetric bandwidth
requirements, i.e. the amount of reserved bandwidth differs requirements, i.e. the amount of reserved bandwidth differs
between the forward and backward directions. between the forward and backward directions.
33 MPLS-TP MUST support unidirectional point-to-multipoint transport 35 MPLS-TP MUST support unidirectional point-to-multipoint transport
paths. paths.
34 MPLS-TP MUST be able to accommodate new types of client networks 36 MPLS-TP MUST be extensible in order to accommodate new types of
and services. client networks and services.
35 MPLS-TP SHOULD support mechanisms to minimize traffic impact
during network reconfiguration.
36 MPLS-TP SHOULD support mechanisms to enable the reserved 37 MPLS-TP SHOULD support mechanisms to enable the reserved
bandwidth associated with a transport path to be increased bandwidth associated with a transport path to be increased
without impacting the > existing traffic on that transport path without impacting the > existing traffic on that transport path
37 MPLS-TP SHOULD support mechanisms to enable the reserved 38 MPLS-TP SHOULD support mechanisms to enable the reserved
bandwidth of a transport path to be decreased without impacting bandwidth of a transport path to be decreased without impacting
the existing traffic on that transport path, provided that the the existing traffic on that transport path, provided that the
level of existing traffic is smaller than the reserved bandwidth level of existing traffic is smaller than the reserved bandwidth
following the decrease. following the decrease.
38 MPLS-TP SHOULD support mechanisms which ensure the integrity of 39 MPLS-TP MUST support mechanisms which ensure the integrity of the
the transported customer's service traffic. transported customer's service traffic.
39 MPLS-TP MUST support an unambiguous and reliable means of 40 MPLS-TP MUST support an unambiguous and reliable means of
distinguishing users' (client) packets from MPLS-TP control distinguishing users' (client) packets from MPLS-TP control
packets (e.g. control plane, management plane, OAM and protection packets (e.g. control plane, management plane, OAM and protection
switching packets). switching packets).
2.4. Control plane requirements 2.4. Control plane requirements
This section defines the requirements that apply to MPLS-TP when a
control plane is deployed.
The requirements for ASON signalling and routing and the requirements The requirements for ASON signalling and routing and the requirements
for multi-region and multi-layer networks as specified in [RFC4139], for multi-region and multi-layer networks as specified in [RFC4139],
[RFC4258] and [RFC5212] respectively apply to MPLS-TP. [RFC4258] and [RFC5212] respectively apply to MPLS-TP.
[ITU-T Comment: the MPLS-TP control plane should meet the
requirements for ASON architecture (G.8080, ...) unless explicitly
excluded as well as the additional MPLS-TP specific requirements
explicitly added.]
[Editors' Note: Following other comments on above references, need to
produce consolidated text that references correct documents &
requirements.]
Additionally: Additionally:
40 MPLS-TP SHOULD support control plane topologies that are 41 The MPLS-TP control pane SHOULD support control plane topology
independent of the data plane topology. and data plane topology independence.
41 The MPLS-TP control plane MUST be able to be operated independent 42 The MPLS-TP control plane MUST be able to be operated independent
of any particular client or server layer control plane. of any particular client or server layer control plane.
42 The MPLS-TP control plane MUST support establishing all the 43 The MPLS-TP control plane MUST support establishing all the
connectivity patterns defined for the MPLS-TP data plane (e.g., connectivity patterns defined for the MPLS-TP data plane (e.g.,
unidirectional and bidirectional P2P, unidirectional P2MP, etc.) unidirectional and bidirectional P2P, unidirectional P2MP, etc.)
including configuration of protection functions and any including configuration of protection functions and any
associated maintenance functions. associated maintenance functions.
43 The MPLS-TP control pane MUST support the configuration and 44 The MPLS-TP control pane MUST support the configuration and
modification of OAM maintenance points as well as the activation/ modification of OAM maintenance points as well as the activation/
deactivation of OAM when the transport path is established or deactivation of OAM when the transport path is established or
modified. modified.
44 An MPLS-TP control plane MUST support operation of the recovery 45 An MPLS-TP control plane MUST support operation of the recovery
functions described in Section 2.8. functions described in Section 2.8.
45 An MPLS-TP control plane MUST scale gracefully to support a large 46 An MPLS-TP control plane MUST scale gracefully to support a large
number of transport paths. number of transport paths, nodes and links.
46 An MPLS-TP control plane SHOULD provide a common control 47 An MPLS-TP control plane SHOULD provide a common control
mechanism for architecturally similar operations. mechanism for architecturally similar operations.
2.5. Network Management (NM) requirements 2.5. Network Management (NM) requirements
For requirements related to NM functionality for MPLS-TP, see the For requirements related to NM functionality (Management Plane in
MPLS-TP NM requirements document [I-D.gray-mpls-tp-nm-req]. ITU-T terminology) for MPLS-TP, see the MPLS-TP NM requirements
document [I-D.gray-mpls-tp-nm-req].
2.6. Operation, Administration and Maintenance (OAM) requirements 2.6. Operation, Administration and Maintenance (OAM) requirements
For requirements related to OAM functionality for MPLS-TP, see the For requirements related to OAM functionality for MPLS-TP, see the
MPLS-TP OAM requirements document MPLS-TP OAM requirements document
[I-D.vigoureux-mpls-tp-oam-requirements]. [I-D.vigoureux-mpls-tp-oam-requirements].
2.7. Network performance management (PM) requirements 2.7. Network performance management (PM) requirements
For requirements related to PM functionality for MPLS-TP, see the For requirements related to PM functionality for MPLS-TP, see the
skipping to change at page 13, line 40 skipping to change at page 14, line 29
Network survivability plays a critical role in the delivery of Network survivability plays a critical role in the delivery of
reliable services. Network availability is a significant contributor reliable services. Network availability is a significant contributor
to revenue and profit. Service guarantees in the form of SLAs to revenue and profit. Service guarantees in the form of SLAs
require a resilient network that rapidly detects facility or node require a resilient network that rapidly detects facility or node
failures and restores network operation in accordance with the terms failures and restores network operation in accordance with the terms
of the SLA. of the SLA.
The requirements in this section use the recovery terminology defined The requirements in this section use the recovery terminology defined
in RFC 4427 [RFC4427]. in RFC 4427 [RFC4427].
47 MPLS-TP MUST provide protection and restoration mechanisms. 48 MPLS-TP MUST provide protection and restoration mechanisms.
A. Recovery techniques used for P2P and P2MP SHOULD be identical A. Recovery techniques used for P2P and P2MP SHOULD be identical
to simplify implementation and operation. However, this MUST to simplify implementation and operation. However, this MUST
NOT override any other requirement. NOT override any other requirement.
48 MPLS-TP recovery mechanisms MUST be applicable at various levels 49 MPLS-TP recovery mechanisms MUST be applicable at various levels
throughout the network including support for span, path segment throughout the network including support for link, path segment
and end-to-end path, and pseudowire segment, and end-to-end and end-to-end path, and pseudowire segment, and end-to-end
pseudowire recovery. pseudowire recovery.
49 MPLS-TP recovery paths MUST meet the SLA protection objectives of 50 MPLS-TP recovery paths MUST meet the SLA protection objectives of
the service. the service.
A. MPLS-TP MUST provide mechanisms to guarantee 50ms recovery A. MPLS-TP MUST provide mechanisms to guarantee 50ms recovery
times from the moment of fault detection in networks with times from the moment of fault detection in networks with
spans less than 1200 km. spans less than 1200 km.
B. For protection it MUST be possible to require protection of B. For protection it MUST be possible to require protection of
100% of the traffic on the protected path. 100% of the traffic on the protected path.
C. Recovery objectives SHOULD be configurable per transport C. Recovery objectives SHOULD be configurable per transport
path, and SHOULD include bandwidth and QoS. path, and SHOULD include bandwidth and QoS.
50 The recovery mechanisms MUST all be applicable to any topology. 51 The recovery mechanisms MUST all be applicable to any topology.
51 The recovery mechanisms MUST operate in synergy with (including 52 The recovery mechanisms MUST operate in synergy with (including
coordination of timing) the recovery mechanisms present in any coordination of timing) the recovery mechanisms present in any
underlying server transport network (for example, Ethernet, SDH, underlying server transport network (for example, Ethernet, SDH,
OTN, WDM) to avoid race conditions between the layers. OTN, WDM) to avoid race conditions between the layers.
52 MPLS-TP protection mechanisms MUST support priority logic to 53 MPLS-TP protection mechanisms MUST support priority logic to
negotiate and accommodate coexisting requests (i.e., multiple negotiate and accommodate coexisting requests (i.e., multiple
requests) for protection switching (e.g., administrative requests requests) for protection switching (e.g., administrative requests
and requests due to link/node failures). and requests due to link/node failures).
53 MPLS-TP recovery and reversion mechanisms MUST prevent frequent 54 MPLS-TP recovery and reversion mechanisms MUST prevent frequent
operation of recovery in the event of an intermittent defect. operation of recovery in the event of an intermittent defect.
[Editors' Note: ITU-T Q9/15 and Q12/15 will provide by <TBD> a
requirement for protection switching time in case of linear
protection (e.g. within 50 ms) together with a reference network.]
2.8.1. Data plane behavior requirements 2.8.1. Data plane behavior requirements
General protection and survivability requirements are expressed in General protection and survivability requirements are expressed in
terms of the behavior in the data plane. terms of the behavior in the data plane.
2.8.1.1. Protection 2.8.1.1. Protection
54 MPLS-TP MUST support 1+1 Protection. 55 MPLS-TP MUST support 1+1 Protection.
A. MPLS-TP 1+1 support MUST include bidirectional protection A. MPLS-TP 1+1 support MUST include bidirectional protection
switching for P2P connectivity, and this SHOULD be the switching for P2P connectivity, and this SHOULD be the
default behavior. default behavior.
B. Unidirectional 1+1 protection for P2MP connectivity MUST be B. Unidirectional 1+1 protection for P2MP connectivity MUST be
supported. supported.
C. Unidirectional 1+1 protection for P2P connectivity is NOT C. Unidirectional 1+1 protection for P2P connectivity is NOT
REQUIRED. REQUIRED.
55 MPLS-TP MUST support 1:n Protection (including 1:1 protection). 56 MPLS-TP MUST support 1:n Protection (including 1:1 protection).
A. MPLS-TP 1:n support MUST include bidirectional protection A. MPLS-TP 1:n support MUST include bidirectional protection
switching for P2P connectivity, and this SHOULD be the switching for P2P connectivity, and this SHOULD be the
default behavior. default behavior.
B. Unidirectional 1:n protection for P2MP connectivity MUST be B. Unidirectional 1:n protection for P2MP connectivity MUST be
supported. supported.
C. Unidirectional 1:n protection for P2P connectivity is NOT C. Unidirectional 1:n protection for P2P connectivity is NOT
REQUIRED. REQUIRED.
D. The action of protection switching MUST NOT cause user data D. The action of protection switching MUST NOT cause user data
to loop. Backtracking is allowed. to loop. Backtracking is allowed.
56 MPLS-TP SHOULD support extra traffic carried on 1:n protection 57 MPLS-TP SHOULD support extra traffic carried on 1:n protection
resources when protection is not in use. resources when protection is not in use.
2.8.1.2. Restoration 2.8.1.2. Restoration
57 The restoration LSP MUST be able to share resources with the LSP 58 The restoration LSP MUST be able to share resources with the LSP
being replaced (sometimes known as soft rerouting). being replaced (sometimes known as soft rerouting).
58 Restoration priority MUST be supported so that an implementation 59 Restoration priority MUST be supported so that an implementation
can determine the order in which transport paths should be can determine the order in which transport paths should be
restored (to minimize service restoration time as well as to gain restored (to minimize service restoration time as well as to gain
access to available spare capacity on the best paths). access to available spare capacity on the best paths).
59 Preemption priority MUST be supported to allow restoration to 60 Preemption priority MUST be supported to allow restoration to
displace other transport paths in the event of resource displace other transport paths in the event of resource
constraint. constraint.
60 Recovery mechanisms MUST be bidirectional. 61 Recovery mechanisms MUST be bidirectional.
2.8.1.3. Sharing of protection resources 2.8.1.3. Sharing of protection resources
61 MPLS-TP SHOULD support 1:n (including 1:1) shared mesh 62 MPLS-TP SHOULD support 1:n (including 1:1) shared mesh
restoration. restoration.
62 MPLS-TP MUST support the sharing of protection bandwidth by 63 MPLS-TP MUST support the sharing of protection bandwidth by
allowing best effort traffic. allowing best effort traffic.
63 MPLS-TP MUST support the definition of shared protection groups 64 MPLS-TP MUST support the definition of shared protection groups
to allow the coordination of protection actions resulting from to allow the coordination of protection actions resulting from
triggers caused by events at different locations in the network. triggers caused by events at different locations in the network.
64 MPLS-TP MUST support sharing of protection resources such that 65 MPLS-TP MUST support sharing of protection resources such that
protection paths that are known not to be required concurrently protection paths that are known not to be required concurrently
can share the same resources. can share the same resources.
2.8.1.4. Reversion 2.8.1.4. Reversion
65 MPLS-TP protection mechanisms MUST support revertive and non- 66 MPLS-TP protection mechanisms MUST support revertive and non-
revertive behavior. Reversion MUST be the default behavior. revertive behavior. Reversion MUST be the default behavior.
66 MPLS-TP restoration mechanisms MAY support revertive and non- 67 MPLS-TP restoration mechanisms MAY support revertive and non-
revertive behavior. revertive behavior.
2.8.2. Triggers for protection, restoration, and reversion 2.8.2. Triggers for protection, restoration, and reversion
Recovery actions may be triggered from different places as follows: Recovery actions may be triggered from different places as follows:
67 MPLS-TP MUST support physical layer fault indication triggers. 68 MPLS-TP MUST support physical layer fault indication triggers.
68 MPLS-TP MUST support OAM-based triggers. 69 MPLS-TP MUST support OAM-based triggers.
69 MPLS-TP MUST support management plane triggers (e.g., forced 70 MPLS-TP MUST support management plane triggers (e.g., forced
switch, etc.). switch, etc.).
70 There MUST be a mechanism to allow administrative recovery 71 There MUST be a mechanism to allow administrative recovery
actions to be distinguished from recovery actions initiated by actions to be distinguished from recovery actions initiated by
other triggers. other triggers.
71 Where a control plane is present, MPLS-TP SHOULD support control 72 Where a control plane is present, MPLS-TP SHOULD support control
plane triggers. plane triggers.
2.8.3. Management plane operation of protection and restoration 2.8.3. Management plane operation of protection and restoration
All functions described here are for control by the operator. All functions described here are for control by the operator.
72 It MUST be possible to configure of protection paths and 73 It MUST be possible to configure of protection paths and
protection-to-working path relationships (sometimes known as protection-to-working path relationships (sometimes known as
protection groups). protection groups).
73 There MUST be support for pre-calculation of recovery paths. 74 There MUST be support for pre-calculation of recovery paths.
74 There MUST be support for pre-provisioning of recovery paths. 75 There MUST be support for pre-provisioning of recovery paths.
75 The following administrative control MUST be supported: 76 The following administrative control MUST be supported:
A. lockout A. lockout
B. forced switchover B. forced switchover
C. manual switchover C. manual switchover
D. simulated fault D. simulated fault
76 There MUST be support for the configuration of timers used for 77 There MUST be support for the configuration of timers used for
recovery operation. recovery operation.
77 Restoration resources MAY be pre-planned and selected a priori, 78 Restoration resources MAY be pre-planned and selected a priori,
or computed after failure occurrence. or computed after failure occurrence.
78 When preemption is supported for recovery purposes, it MUST be 79 When preemption is supported for recovery purposes, it MUST be
possible for the operator to configure it. possible for the operator to configure it.
79 The management plane MUST provide indications of protection 80 The management plane MUST provide indications of protection
events and triggers. events and triggers.
80 The management plane MUST allow the current protection status of 81 The management plane MUST allow the current protection status of
all transport paths to be determined. all transport paths to be determined.
2.8.4. Control plane and in-band OAM operation of recovery 2.8.4. Control plane and in-band OAM operation of recovery
81 The MPLS-TP control plane (which is not mandatory in an MPLS-TP 82 The MPLS-TP control plane (which is not mandatory in an MPLS-TP
implementation) MUST support: implementation) MUST support:
A. establishment and maintenance of all recovery entities and A. establishment and maintenance of all recovery entities and
functions functions
B. signaling of administrative control B. signaling of administrative control
C. protection state coordination (PSC) C. protection state coordination (PSC)
82 In-band OAM MAY be used for: 83 In-band OAM MAY be used for:
A. signaling of administrative control A. signaling of administrative control
B. protection state coordination B. protection state coordination
2.8.5. Topology-specific recovery mechanisms 2.8.5. Topology-specific recovery mechanisms
83 MPLS-TP MAY support recovery mechanisms that are optimized for 84 MPLS-TP MAY support recovery mechanisms that are optimized for
specific network topologies. These mechanisms MUST be specific network topologies. These mechanisms MUST be
interoperable with the mechanisms defined for arbitrary topology interoperable with the mechanisms defined for arbitrary topology
(mesh) networks to enable protection of end-to-end transport (mesh) networks to enable protection of end-to-end transport
paths. paths.
Note that topology-specific recovery mechanisms are subject to the Note that topology-specific recovery mechanisms are subject to the
development of requirements using the normal IETF process. development of requirements using the normal IETF process.
2.8.5.1. Ring protection 2.8.5.1. Ring protection
skipping to change at page 19, line 4 skipping to change at page 19, line 42
It may be observed that this list is fully compatible with the It may be observed that this list is fully compatible with the
generic requirements expressed above, and that no requirements that generic requirements expressed above, and that no requirements that
are specific to ring topologies have been identified. [Editors' are specific to ring topologies have been identified. [Editors'
Note: This statement is to be confirmed at the end of the work and Note: This statement is to be confirmed at the end of the work and
may be removed if it does not hold.] may be removed if it does not hold.]
In the list of requirements below, those requirements that are In the list of requirements below, those requirements that are
generic are marked "[G]"; those that are Ring-specific are marked generic are marked "[G]"; those that are Ring-specific are marked
"[R]". [Editors' Note: Still need to mark up the requirements below "[R]". [Editors' Note: Still need to mark up the requirements below
as [R] and [G].] as [R] and [G].]
84 MPLS-TP MUST include recovery mechanisms that operate in any
85 MPLS-TP MUST include recovery mechanisms that operate in any
single ring supported in MPLS-TP, and continue to operate within single ring supported in MPLS-TP, and continue to operate within
the single rings even when the rings are interconnected. the single rings even when the rings are interconnected.
85 When a network is constructed from interconnected rings, MPLS-TP 86 When a network is constructed from interconnected rings, MPLS-TP
MUST support recovery mechanisms that protect user data that MUST support recovery mechanisms that protect user data that
traverses more than one ring. This includes the possibility of traverses more than one ring. This includes the possibility of
failure of the ring-interconnect nodes and links. failure of the ring-interconnect nodes and links.
86 MPLS-TP recovery in a ring MUST protect unidirectional and 87 MPLS-TP recovery in a ring MUST protect unidirectional and
bidirectional P2P transport paths. bidirectional P2P transport paths.
87 MPLS-TP recovery in a ring MUST protect unidirectional P2MP 88 MPLS-TP recovery in a ring MUST protect unidirectional P2MP
transport paths. transport paths.
88 MPLS-TP 1+1 and 1:1 protection in a ring MUST support switching 89 MPLS-TP 1+1 and 1:1 protection in a ring MUST support switching
time within 50 ms from the moment of fault detection in a network time within 50 ms from the moment of fault detection in a network
with a 16 nodes ring with less than 1200 km of fiber. This is with a 16 nodes ring with less than 1200 km of fiber. This is
NOT REQUIRED when extra traffic is present. NOT REQUIRED when extra traffic is present.
[Editor note: the opinion of some people in the T103 room in Geneva [Editor note: the opinion of some people in the T103 room in Geneva
is that support for extra traffic is NOT REQUIRED in ring topologies. is that support for extra traffic is NOT REQUIRED in ring topologies.
It may be further NOT REQUIRED in any topology. This is for further It may be further NOT REQUIRED in any topology. This is for further
discussion especially with respect to G.8131.] discussion especially with respect to G.8131.]
89 The protection switching time in a ring MUST be independent of 90 The protection switching time in a ring MUST be independent of
the number of LSPs crossing the ring. the number of LSPs crossing the ring.
90 Recovery actions in a ring MUST be data plane functions 91 Recovery actions in a ring MUST be data plane functions
triggered by different elements of control. The triggers are triggered by different elements of control. The triggers are
configured by management or control planes and are subject to configured by management or control planes and are subject to
configurable policy. configurable policy.
91 The configuration and operation of recovery mechanisms in a ring 92 The configuration and operation of recovery mechanisms in a ring
MUST scale well with: MUST scale well with:
A. the number of transport paths (must be better than linear A. the number of transport paths (must be better than linear
scaling) scaling)
B. the number of nodes on the ring (must be at least as good as B. the number of nodes on the ring (must be at least as good as
linear scaling) linear scaling)
C. the number of ring interconnects (must be at least as good C. the number of ring interconnects (must be at least as good
as linear scaling) as linear scaling)
92 MPLS-TP recovery in ring topologies MAY support multiple
93 MPLS-TP recovery in ring topologies MAY support multiple
failures without reconfiguring the protection actions. failures without reconfiguring the protection actions.
93 Recovery techniques used in a ring MUST NOT prevent the ring 94 Recovery techniques used in a ring MUST NOT prevent the ring
from being connected to a general MPLS-TP network in any from being connected to a general MPLS-TP network in any
arbitrary way, and MUST NOT prevent the operation of recovery arbitrary way, and MUST NOT prevent the operation of recovery
techniques in the rest of the network. techniques in the rest of the network.
94 MPLS-TP Recovery mechanisms applicable to a ring MUST be equally 95 MPLS-TP Recovery mechanisms applicable to a ring MUST be equally
applicable in physical and logical rings. applicable in physical and logical rings.
95 Recovery techniques in a ring SHOULD be identical to those in 96 Recovery techniques in a ring SHOULD be identical to those in
general networks to simplify implementation. However, this MUST general networks to simplify implementation. However, this MUST
NOT override any other requirement. NOT override any other requirement.
96 Recovery techniques in logical and physical rings SHOULD be 97 Recovery techniques in logical and physical rings SHOULD be
identical to simplify implementation and operation. However, identical to simplify implementation and operation. However,
this MUST NOT override any other requirement. this MUST NOT override any other requirement.
97 The default recovery scheme in a ring MUST be bidirectional 98 The default recovery scheme in a ring MUST be bidirectional
recovery in order to simplify the recovery operation. recovery in order to simplify the recovery operation.
98 The recovery mechanism in a ring MUST support revertive 99 The recovery mechanism in a ring MUST support revertive
switching, which MUST be the default behaviour. This allows switching, which MUST be the default behaviour. This allows
optimization of the use of the ring resources, and restores the optimization of the use of the ring resources, and restores the
preferred quality conditions for normal traffic (e.g., delay) preferred quality conditions for normal traffic (e.g., delay)
when the recovery mechanism is no longer needed. when the recovery mechanism is no longer needed.
99 The recovery mechanisms in a ring MUST support ways to allow 100 The recovery mechanisms in a ring MUST support ways to allow
administrative protection switching, to be distinguished from administrative protection switching, to be distinguished from
protection switching initiated by other triggers. protection switching initiated by other triggers.
100 It MUST be possible to disable protection mechanisms on selected 101 It MUST be possible to disable protection mechanisms on selected
links in a ring (depending on operator's need). links in a ring (depending on operator's need).
[Editor note: This requirement was originated from ITU-T Q9/15 and [Editor note: This requirement was originated from ITU-T Q9/15 and
needs further clarification. If it means that a lockout is required needs further clarification. If it means that a lockout is required
for use on specific spans, then this is already covered by a general for use on specific spans, then this is already covered by a general
requirement, and this requirement could be deleted or rewritten for requirement, and this requirement could be deleted or rewritten for
clarity. On the other hand, there may be another meaning in which clarity. On the other hand, there may be another meaning in which
case the requirement needs to be rewritten.] case the requirement needs to be rewritten.]
101 MPLS-TP recovery mechanisms in a ring MUST include a mechanism 102 MPLS-TP recovery mechanisms in a ring MUST include a mechanism
to allow an implementation to handle coexisting requests (i.e., to allow an implementation to handle coexisting requests (i.e.,
multiple requests - not necessarily arriving simultaneously) for multiple requests - not necessarily arriving simultaneously) for
protection switching based on priority. protection switching based on priority.
102 MPLS-TP recovery and reversion mechanisms in a ring MUST offer a 103 MPLS-TP recovery and reversion mechanisms in a ring MUST offer a
way to prevent frequent operation of recovery in the event of an way to prevent frequent operation of recovery in the event of an
intermittent defect. intermittent defect.
103 MPLS-TP MUST support the sharing of protection bandwidth in a 104 MPLS-TP MUST support the sharing of protection bandwidth in a
ring by allowing best effort traffic. ring by allowing best effort traffic.
104 MPLS-TP MUST support sharing of ring protection resources such 105 MPLS-TP MUST support sharing of ring protection resources such
that protection paths that are known not to be required that protection paths that are known not to be required
concurrently can share the same resources. concurrently can share the same resources.
105 MUST support the coordination of triggers caused by events at 106 MUST support the coordination of triggers caused by events at
different locations in a ring. Note that this is the ring different locations in a ring. Note that this is the ring
equivalent of the definition of shared protection groups. equivalent of the definition of shared protection groups.
2.9. QoS requirements 2.9. QoS requirements
Carriers require advanced traffic management capabilities to enforce Carriers require advanced traffic management capabilities to enforce
and guarantee the QoS parameters of customers' SLAs. and guarantee the QoS parameters of customers' SLAs.
Quality of service mechanisms are REQUIRED in an MPLS-TP network to Quality of service mechanisms are REQUIRED in an MPLS-TP network to
ensure: ensure:
106 Support for differentiated services and different traffic types 107 Support for differentiated services and different traffic types
with traffic class separation associated with different traffic. with traffic class separation associated with different traffic.
107 Prioritization of critical services. 108 Prioritization of critical services.
108 Enabling the provisioning and the guarantee of Service Level 109 Enabling the provisioning and the guarantee of Service Level
Specifications (SLS), with support for hard and relative end-to- Specifications (SLS), with support for hard and relative end-to-
end bandwidth guaranteed. end bandwidth guaranteed.
109 Controlled jitter and delay. 110 Support of services, which are sensitive to jitter and delay.
110 Guarantee of fair access to shared resources. 111 Guarantee of fair access, within a particular class, to shared
resources.
111 Resources for control and management plane packets so that data 112 Guaranteed resources for in-band control and management plane
plane traffic, regardless of the amount, will not cause control traffic regardless of the amount of data plane traffic.
and management functions to become inoperative.
112 Carriers are provided with the capability to efficiently support 113 Carriers are provided with the capability to efficiently support
service demands over the MPLS-TP network. This MUST include service demands over the MPLS-TP network. This MUST include
support for a flexible bandwidth allocation scheme. support for a flexible bandwidth allocation scheme.
[Editors' Note: Should we refer here to the requirements specified in [Editors' Note: Should we refer here to the requirements specified in
RFC 2702?] RFC 2702?]
2.10. Security requirements 2.10. Security requirements
For a description of the security threats relevant in the context of For a description of the security threats relevant in the context of
MPLS and GMPLS and the defensive techniques to combat those threats MPLS and GMPLS and the defensive techniques to combat those threats
skipping to change at page 25, line 19 skipping to change at page 26, line 4
Email: betts01@nortel.com Email: betts01@nortel.com
Nurit Sprecher Nurit Sprecher
Nokia Siemens Networks Nokia Siemens Networks
3 Hanagar St. Neve Ne'eman B 3 Hanagar St. Neve Ne'eman B
Hod Hasharon, 45241 Hod Hasharon, 45241
Israel Israel
Email: nurit.sprecher@nsn.com Email: nurit.sprecher@nsn.com
Satoshi Ueno Satoshi Ueno
NTT NTT
Email: satoshi.ueno@ntt.com Email: satoshi.ueno@ntt.com
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
 End of changes. 128 change blocks. 
179 lines changed or deleted 226 lines changed or added

This html diff was produced by rfcdiff 1.35. The latest version is available from http://tools.ietf.org/tools/rfcdiff/