draft-ietf-ccamp-gmpls-recovery-terminology-03.txt   draft-ietf-ccamp-gmpls-recovery-terminology-04.txt 
CCAMP Working Group CCAMP GMPLS P&R Design Team CCAMP Working Group CCAMP GMPLS P&R Design Team
Internet Draft Internet Draft
Category: Standard Track Eric Mannie (Editor) Category: Standards Track Eric Mannie (Editor)
Expiration Date: June 2004 Dimitri Papadimitriou (Editor) Expiration Date: October 2004 Dimitri Papadimitriou (Editor)
January 2004 April 2004
Recovery (Protection and Restoration) Terminology for GMPLS Recovery (Protection and Restoration) Terminology
for Generalized Multi-Protocol Label Switching (GMPLS)
draft-ietf-ccamp-gmpls-recovery-terminology-03.txt draft-ietf-ccamp-gmpls-recovery-terminology-04.txt
Status of this Memo Status of this Memo
This document is an Internet-Draft and is subject to all provisions This document is an Internet-Draft and is subject to all provisions
of Section 10 of RFC2026. of Section 10 of RFC2026.
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 other Task Force (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet-Drafts. groups may also distribute working documents as Internet-Drafts.
skipping to change at line 36 skipping to change at line 36
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html. http://www.ietf.org/1id-abstracts.html.
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.
For potential updates to the above required-text see: For potential updates to the above required-text see:
http://www.ietf.org/ietf/1id-guidelines.txt http://www.ietf.org/ietf/1id-guidelines.txt
1. Abstract Abstract
This document defines a common terminology for Generalized Multi- This document defines a common terminology for Generalized Multi-
Protocol Label Switching (GMPLS) based recovery mechanisms (i.e. Protocol Label Switching (GMPLS) based recovery mechanisms (i.e.
protection and restoration) that are under consideration by the protection and restoration). The terminology is independent of the
CCAMP Working Group. The proposed terminology is intended to be underlying transport technologies covered by GMPLS.
independent of the underlying transport technologies covered by
GMPLS.
E.Mannie, D.Papadimitriou et al. 1 E.Mannie, D.Papadimitriou et al. - Standards Track 1
2. Contributors Table of Contents
Status of this Memo .............................................. 1
Abstract ......................................................... 1
Table of Contents ................................................ 2
1. Contributors .................................................. 3
2. Introduction .................................................. 3
3. Conventions used in this document ............................. 4
4. Recovery Terminology Common to Protection and Restoration ..... 4
4.1 Working and Recovery LSP/Span ................................ 5
4.2 Traffic Types ................................................ 5
4.3 LSP/Span Protection and Restoration .......................... 6
4.4 Recovery Scope ............................................... 6
4.5 Recovery Domain .............................................. 7
4.6 Recovery Types ............................................... 7
4.7 Bridge Types ................................................. 9
4.8 Selector Types ............................................... 9
4.9 Recovery GMPLS Nodes ........................................ 10
4.10 Switch-over Mechanism ...................................... 10
4.11 Reversion operations ....................................... 10
4.12 Failure Reporting .......................................... 11
4.13 External commands .......................................... 11
4.14 Unidirectional versus Bi-Directional Recovery Switching .... 12
4.15 Full versus Partial Span Recovery Switching ................ 12
4.16 Recovery Schemes Related Time and Durations ................ 13
4.17 Impairment ................................................. 13
4.18 Recovery Ratio ............................................. 13
4.19 Hitless Protection Switch-over ............................. 14
4.20 Network Survivability ...................................... 14
4.21 Survivable Network ......................................... 14
4.22 Escalation ................................................. 14
5. Recovery Phases .............................................. 14
5.1 Entities Involved During Recovery ........................... 15
6. Protection Schemes ........................................... 16
6.1 1+1 Protection .............................................. 16
6.2 1:N (N >= 1) Protection ..................................... 16
6.3 M:N (M, N > 1, N >= M) Protection ........................... 16
6.4 Notes on Protection Schemes ................................. 16
7. Restoration Schemes .......................................... 17
7.1 Pre-planned LSP Restoration ................................. 17
7.1.1 Shared-Mesh Restoration ................................... 17
7.2 LSP Restoration ............................................. 17
7.2.1 Hard LSP Restoration ...................................... 18
7.2.2 Soft LSP Restoration ...................................... 18
8. Security Considerations ...................................... 18
9. Intellectual Property Consideration .......................... 18
9.1 IPR Disclosure Acknowledgement .............................. 18
10. References .................................................. 19
10.1 Normative References ....................................... 19
10.2 Informative References ..................................... 19
11. Acknowledgments ............................................. 20
12. Editor's Addresses .......................................... 20
E.Mannie, D.Papadimitriou et al.- Standards Track 2
1. Contributors
This document is the result of the CCAMP Working Group Protection This document is the result of the CCAMP Working Group Protection
and Restoration design team joint effort. The following are the and Restoration design team joint effort. The following are the
authors that contributed to the present memo: authors that contributed to the present memo:
Deborah Brungard (AT&T) Deborah Brungard (AT&T)
Rm. D1-3C22 - 200 S. Laurel Ave. Rm. D1-3C22 - 200 S. Laurel Ave.
Middletown, NJ 07748, USA Middletown, NJ 07748, USA
E-mail: dbrungard@att.com EMail: dbrungard@att.com
Sudheer Dharanikota (Consult) Sudheer Dharanikota
E-mail: sudheer@ieee.org EMail: sudheer@ieee.org
Jonathan P. Lang (Rincon Networks) Jonathan P. Lang (Rincon Networks)
E-mail: jplang@ieee.org EMail: jplang@ieee.org
Guangzhi Li (AT&T) Guangzhi Li (AT&T)
180 Park Avenue, 180 Park Avenue,
Florham Park, NJ 07932, USA Florham Park, NJ 07932, USA
E-mail: gli@research.att.com EMail: gli@research.att.com
Eric Mannie (Consult) Eric Mannie
Email: eric_mannie@hotmail.com EMail: eric_mannie@hotmail.com
Dimitri Papadimitriou (Alcatel) Dimitri Papadimitriou (Alcatel)
Fr. Wellesplein, 1 Fr. Wellesplein, 1
B-2018, Antwerpen, Belgium B-2018, Antwerpen, Belgium
Email: dimitri.papadimitriou@alcatel.be EMail: dimitri.papadimitriou@alcatel.be
Bala Rajagopalan (Tellium) Bala Rajagopalan
2 Crescent Place - P.O. Box 901 EMail: braj@earthlink.net
Oceanport, NJ 07757-0901, USA
E-mail: braja@tellium.com
Yakov Rekhter (Juniper) Yakov Rekhter (Juniper)
1194 N. Mathilda Avenue 1194 N. Mathilda Avenue
Sunnyvale, CA 94089, USA Sunnyvale, CA 94089, USA
E-mail: yakov@juniper.net EMail: yakov@juniper.net
3. Introduction 2. Introduction
This document defines a common terminology for Generalized MPLS This document defines a common terminology for Generalized Multi-
(GMPLS) based recovery mechanisms (i.e. protection and restoration) Protocol Label Switching (GMPLS) based recovery mechanisms (i.e.
that are under consideration by the CCAMP Working Group. protection and restoration) that are under consideration by the
CCAMP Working Group.
The terminology proposed in this document is intended to be The terminology proposed in this document is independent of the
independent of the underlying transport technologies and borrows underlying transport technologies and borrows from the G.808.1 ITU-T
from an ITU-T ongoing effort, the Draft Recommendation [G.808.1] Recommendation [G.808.1] and from the G.841 ITU-T Recommendation
(ex. G.GPS - Generic Protection Switching) and from the G.841 ITU-T [G.841]. The restoration terminology and concepts have been gathered
Recommendation. The restoration terminology and concepts have been from numerous sources including IETF drafts.
gathered from numerous sources including IETF drafts.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 2 E.Mannie, D.Papadimitriou et al.- Standards Track 3
In the context of this document we will use the term "recovery" to In the context of this document, the term "recovery" denotes both
denote both protection and restoration. The specific terms protection and restoration. The specific terms "protection" and
"protection" and "restoration" will only be used when "restoration" will only be used when differentiation is required.
differentiation is required.
Note that this document focuses on the terminology for the recovery Note that this document focuses on the terminology for the recovery
of LSPs controlled by a GMPLS control plane. We focus on end-to-end, of LSPs controlled by a GMPLS control plane. We focus on end-to-end,
segment and span (i.e. link) LSP recovery. Terminology for control segment, and span (i.e. link) Label Switched Path (LSP) recovery.
plane recovery is not in the scope of this document. Terminology for control plane recovery is not in the scope of this
document.
Protection and restoration of switched LSPs under tight time Protection and restoration of switched LSPs under tight time
constraints is a challenging problem. This is particularly relevant constraints is a challenging problem. This is particularly relevant
to optical networks that consist of TDM and/or all-optical to optical networks that consist of Time Division Multiplex (TDM)
(photonic) cross-connects referred to as GMPLS nodes (or simply and/or all-optical (photonic) cross-connects referred to as GMPLS
nodes, or even sometimes "LSRs") connected in a general topology nodes (or simply nodes, or even sometimes "Label Switching Routers,
[GMPLS-ARCH]. or LSRs") connected in a general topology [GMPLS-ARCH].
Recovery typically involves the activation of a recovery (or Recovery typically involves the activation of a recovery (or
alternate) LSP when a failure is encountered in the working (or alternate) LSP when a failure is encountered in the working (or
primary) LSP. primary) LSP.
A working or recovery LSP is characterized by an ingress interface, A working or recovery LSP is characterized by an ingress interface,
an egress interface, and a set of intermediate nodes and spans an egress interface, and a set of intermediate nodes and spans
through which the LSP is routed. The working and recovery LSPs are through which the LSP is routed. The working and recovery LSPs are
typically resource disjoint (e.g. node and/or span disjoint). This typically resource disjoint (e.g. node and/or span disjoint). This
ensures that a single failure will not affect both the working and ensures that a single failure will not affect both the working and
recovery LSPs. recovery LSPs.
A bi-directional span between neighboring nodes is usually realized A bi-directional span between neighboring nodes is usually realized
as a pair of unidirectional spans. The end-to-end path for a bi- as a pair of unidirectional spans. The end-to-end path for a bi-
directional LSP therefore consists of a series of bi-directional directional LSP therefore consists of a series of bi-directional
segments (i.e. Sub-Network Connections, or SNCs, in the ITU-T segments (i.e. Sub-Network Connections, or SNCs, in the ITU-T
terminology) between the source and destination nodes, traversing terminology) between the source and destination nodes, traversing
intermediate nodes. intermediate nodes.
Conventions used in this document: 3. Conventions used in this document:
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 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC-2119 [1]. this document are to be interpreted as described in [RFC2119].
4. Recovery Terminology Common to Protection and Restoration 4. Recovery Terminology Common to Protection and Restoration
This section defines the following general terms common to both This section defines the following general terms common to both
protection and restoration (i.e. recovery). In addition, most of protection and restoration (i.e. recovery). In addition, most of
these terms apply to end-to-end, segment and span LSP recovery. Note these terms apply to end-to-end, segment and span LSP recovery. Note
that span recovery does not protect the nodes at each end of the that span recovery does not protect the nodes at each end of the
span, otherwise end-to-end or segment LSP recovery should be used. span, otherwise end-to-end or segment LSP recovery should be used.
The terminology and the definitions have been originally taken from The terminology and the definitions have been originally taken from
G.808.1. However, for generalization, the following language that is [G.808.1]. However, for generalization, the following language that
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 3 E.Mannie, D.Papadimitriou et al.- Standards Track 4
not directly related to recovery has been adapted to GMPLS and the is not directly related to recovery has been adapted to GMPLS and
common IETF terminology: the common IETF terminology:
An LSP is used as a generic term to designate either an SNC (Sub- An LSP is used as a generic term to designate either an SNC (Sub-
Network Connection) or an NC (Network Connection) in ITU-T Network Connection) or an NC (Network Connection) in ITU-T
terminology. The ITU-T uses the term transport entity to designate terminology. The ITU-T uses the term transport entity to designate
either a link, an SNC or an NC. The term "Traffic" is used instead either a link, an SNC or an NC. The term "Traffic" is used instead
of "Traffic Signal". The term protection or restoration "scheme" is of "Traffic Signal". The term protection or restoration "scheme" is
used instead of protection or restoration "architecture". used instead of protection or restoration "architecture".
The reader is invited to read G.841 and G.808.1 for references to The reader is invited to read [G.841] and [G.808.1] for references
SDH protection and ITU-T generic protection terminology. Note that to SDH protection and Generic Protection Switching terminology,
restoration is not in the scope of G.808.1. respectively. Note that restoration is not in the scope of
[G.808.1].
4.1 Working and Recovery LSP/Span 4.1 Working and Recovery LSP/Span
A working LSP/span is an LSP/span transporting "normal" user A working LSP/span is an LSP/span transporting "normal" user
traffic. A recovery LSP/span is an LSP/span used to transport traffic. A recovery LSP/span is an LSP/span used to transport
"normal" user traffic when the working LSP/span fails. Additionally, "normal" user traffic when the working LSP/span fails. Additionally,
the recovery LSP/span may transport "extra" user traffic (i.e. pre- the recovery LSP/span may transport "extra" user traffic (i.e. pre-
emptable traffic) when normal traffic is carried over the working emptable traffic) when normal traffic is carried over the working
LSP/span. LSP/span.
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(the working and recovery LSPs/spans). (the working and recovery LSPs/spans).
B. Extra traffic: B. Extra traffic:
User traffic carried over recovery resources (e.g. a recovery User traffic carried over recovery resources (e.g. a recovery
LSP/span) when these resources are not being used for the recovery LSP/span) when these resources are not being used for the recovery
of normal traffic; i.e. when the recovery resources are in standby of normal traffic; i.e. when the recovery resources are in standby
mode. When the recovery resources are required to recover normal mode. When the recovery resources are required to recover normal
traffic from the failed working LSP/span, the extra traffic is pre- traffic from the failed working LSP/span, the extra traffic is pre-
empted. Extra traffic is not protected by definition, but may be empted. Extra traffic is not protected by definition, but may be
restored. restored. Moreover, extra traffic does not need to commence or be
terminated at the ends of the LSPs/spans that it uses.
C. Null traffic: C. Null traffic:
Traffic carried over the recovery LSP/span if it is not used to Traffic carried over the recovery LSP/span if it is not used to
carry normal or extra traffic. Null traffic can be any kind of carry normal or extra traffic. Null traffic can be any kind of
traffic that conforms to the signal structure of the specific layer, traffic that conforms to the signal structure of the specific layer,
and it is ignored (not selected) at the egress of the recovery and it is ignored (not selected) at the egress of the recovery
LSP/span. LSP/span.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 4 E.Mannie, D.Papadimitriou et al.- Standards Track 5
4.3 LSP/Span Protection and Restoration 4.3 LSP/Span Protection and Restoration
The following subtle distinction is generally made between the terms The following subtle distinction is generally made between the terms
"protection" and "restoration", even though these terms are often "protection" and "restoration", even though these terms are often
used interchangeably [TEWG]. used interchangeably [RFC3386].
The distinction between protection and restoration is made based on The distinction between protection and restoration is made based on
the resource allocation done during the recovery LSP/span the resource allocation done during the recovery LSP/span
establishment. The distinction between different types of establishment. The distinction between different types of
restoration is made based on the level of route computation, restoration is made based on the level of route computation,
signaling and resource allocation done during the restoration signaling and resource allocation done during the restoration
LSP/span establishment. LSP/span establishment.
A. LSP/Span Protection A. LSP/Span Protection
LSP/span protection denotes the paradigm whereby one or more LSP/span protection denotes the paradigm whereby one or more
dedicated protection LSP(s)/span(s) is/are fully established to dedicated protection LSP(s)/span(s) is/are fully established to
protect one ore more working LSP(s)/span(s). protect one or more working LSP(s)/span(s).
For a protection LSP, this implies that route computation took For a protection LSP, this implies that route computation took
place, that the LSP was fully signaled all the way and that its place, that the LSP was fully signaled all the way and that its
resources were fully selected (i.e. allocated) and cross-connected resources were fully selected (i.e. allocated) and cross-connected
between the ingress and egress nodes. between the ingress and egress nodes.
For a protection span, this implies that the span has been selected For a protection span, this implies that the span has been selected
and reserved for protection. and reserved for protection.
Indeed, it means that no signaling takes place to establish the Indeed, it means that no signaling takes place to establish the
protecting LSP/span when a failure occurs. However, various other protection LSP/span when a failure occurs. However, various other
kinds of signaling may take place between the ingress and egress kinds of signaling may take place between the ingress and egress
nodes for fault notification, to synchronize their use of the nodes for fault notification, to synchronize their use of the
protecting LSP/span, for reversion, etc. protection LSP/span, for reversion, etc.
B. LSP/Span Restoration B. LSP/Span Restoration
LSP/span restoration denotes the paradigm whereby some restoration LSP/span restoration denotes the paradigm whereby some restoration
resources may be pre-computed, signaled and selected a priori, but resources may be pre-computed, signaled and selected a priori, but
not cross-connected to restore a working LSP/span. The complete not cross-connected to restore a working LSP/span. The complete
establishment of the restoration LSP/span occurs only after a establishment of the restoration LSP/span occurs only after a
failure of the working LSP/span, and requires some additional failure of the working LSP/span, and requires some additional
signaling. signaling.
Both protection and restoration require signaling. Signaling to Both protection and restoration require signaling. Signaling to
establish the recovery resources and signaling associated with the establish the recovery resources and signaling associated with the
use of the recovery LSP(s)/span(s) are needed. use of the recovery LSP(s)/span(s) are needed.
4.4 Recovery Scope 4.4 Recovery Scope
Recovery can be applied at various levels throughout the network. An Recovery can be applied at various levels throughout the network. An
LSP may be subject to local (span), segment, and/or end-to-end LSP may be subject to local (span), segment, and/or end-to-end
recovery. recovery.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 5 E.Mannie, D.Papadimitriou et al.- Standards Track 6
Local (span) recovery refers to the recovery of an LSP over a link Local (span) recovery refers to the recovery of an LSP over a link
between two nodes. between two nodes.
End-to-end recovery refers to the recovery of an entire LSP from its End-to-end recovery refers to the recovery of an entire LSP from its
source (ingress node end-point) to its destination (egress node end- source (ingress node end-point) to its destination (egress node end-
point). point).
Segment recovery refers to the recovery over a portion of the Segment recovery refers to the recovery over a portion of the
network of a segment LSP (i.e. an SNC in the ITU-T terminology) of network of a segment LSP (i.e. an SNC in the ITU-T terminology) of
an end-to-end LSP. Such recovery protects against span and/or node an end-to-end LSP. Such recovery protects against span and/or node
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4.5 Recovery Domain 4.5 Recovery Domain
A recovery domain is defined as a set of nodes and spans over which A recovery domain is defined as a set of nodes and spans over which
one or more recovery schemes are provided. A recovery domain served one or more recovery schemes are provided. A recovery domain served
by one single recovery scheme is referred to as a "single recovery by one single recovery scheme is referred to as a "single recovery
domain", while a recovery domain served by multiple recovery schemes domain", while a recovery domain served by multiple recovery schemes
is referred to as a "multi recovery domain". is referred to as a "multi recovery domain".
The recovery operation is contained within the recovery domain. A The recovery operation is contained within the recovery domain. A
GMPLS recovery domain must be entirely contained within a GMPLS GMPLS recovery domain must be entirely contained within a GMPLS
domain. A GMPLS domain may contain multiple recovery domains. domain. A GMPLS domain (defined as a set of nodes and spans
controlled by GMPLS) may contain multiple recovery domains.
4.6 Recovery Types 4.6 Recovery Types
The different recovery types can be classified depending on the The different recovery types can be classified depending on the
number of recovery LSPs/spans that are protecting a given number of number of recovery LSPs/spans that are protecting a given number of
working LSPs/spans. The definitions given hereafter are from the working LSPs/spans. The definitions given hereafter are from the
point of view of a working LSP/span that needs to be protected by a point of view of a working LSP/span that needs to be protected by a
recovery scheme. recovery scheme.
A. 1+1 type: dedicated protection A. 1+1 type: dedicated protection
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restoration. restoration.
B. 0:1 type: unprotected B. 0:1 type: unprotected
No specific recovery LSP/span protects the working LSP/span. No specific recovery LSP/span protects the working LSP/span.
However, the working LSP/span can potentially be restored through However, the working LSP/span can potentially be restored through
any alternate available route/span, with or without any pre-computed any alternate available route/span, with or without any pre-computed
restoration route. Note that there are no resources pre-established restoration route. Note that there are no resources pre-established
for this recovery type. for this recovery type.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 6 E.Mannie, D.Papadimitriou et al.- Standards Track 7
This type is applicable to LSP/span restoration, but not to LSP/span This type is applicable to LSP/span restoration, but not to LSP/span
protection. Span restoration can be for instance achieved by moving protection. Span restoration can be for instance achieved by moving
all the LSPs transported over of a failed span to a dynamically all the LSPs transported over of a failed span to a dynamically
selected span. selected span.
C. 1:1 type: dedicated recovery with extra traffic C. 1:1 type: dedicated recovery with extra traffic
One specific recovery LSP/span protects exactly one specific working One specific recovery LSP/span protects exactly one specific working
LSP/span but the normal traffic is transmitted only over one LSP LSP/span but the normal traffic is transmitted only over one LSP
(working or recovery) at a time. Extra traffic can be transported (working or recovery) at a time. Extra traffic can be transported
skipping to change at line 351 skipping to change at line 405
decision. decision.
This type is applicable to LSP/span protection and LSP restoration, This type is applicable to LSP/span protection and LSP restoration,
but not to span restoration. but not to span restoration.
Note: a shared recovery where each recovery resource can be shared Note: a shared recovery where each recovery resource can be shared
by a maximum of X LSPs/spans is not defined as a recovery type but by a maximum of X LSPs/spans is not defined as a recovery type but
as a recovery scheme. The choice of X is a network resource as a recovery scheme. The choice of X is a network resource
management policy decision. management policy decision.
E. M:N (M, N > 1; M =< N) type: E. M:N (M, N > 1, N >= M) type:
A set of M specific recovery LSPs/spans protects a set of up to N A set of M specific recovery LSPs/spans protects a set of up to N
specific working LSPs/spans. The two sets are explicitly identified. specific working LSPs/spans. The two sets are explicitly identified.
Extra traffic can be transported over the M recovery LSPs/spans when Extra traffic can be transported over the M recovery LSPs/spans when
available. All the LSPs/spans must start and end at the same nodes. available. All the LSPs/spans must start and end at the same nodes.
Sometimes, the working LSPs/spans are assumed to be resource Sometimes, the working LSPs/spans are assumed to be resource
disjoint in the network so that they do not share any failure disjoint in the network so that they do not share any failure
probability, but this is not mandatory. Obviously, if several probability, but this is not mandatory. Obviously, if several
working LSPs/spans in the set of N are concurrently affected by some working LSPs/spans in the set of N are concurrently affected by some
failure(s), the traffic on only M of these failed LSPs/spans may be failure(s), the traffic on only M of these failed LSPs/spans may be
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 7 E.Mannie, D.Papadimitriou et al.- Standards Track 8
recovered. Note that N can be arbitrarily large (i.e. infinite). The recovered. Note that N can be arbitrarily large (i.e. infinite). The
choice of N and M is a policy decision. choice of N and M is a policy decision.
This type is applicable to LSP/span protection and LSP restoration, This type is applicable to LSP/span protection and LSP restoration,
but not to span restoration. but not to span restoration.
4.7 Bridge Types 4.7 Bridge Types
A bridge is the function that connects the normal traffic and extra A bridge is the function that connects the normal traffic and extra
traffic to the working and recovery LSP/span. traffic to the working and recovery LSP/span.
skipping to change at line 415 skipping to change at line 469
Is a selector that extracts the normal traffic from either the Is a selector that extracts the normal traffic from either the
working LSP/span output or the recovery LSP/span output. working LSP/span output or the recovery LSP/span output.
B. Merging selector B. Merging selector
For 1:N and M:N protection types, the selector permanently extracts For 1:N and M:N protection types, the selector permanently extracts
the normal traffic from both the working and recovery LSP/span the normal traffic from both the working and recovery LSP/span
outputs. This alternative works only in combination with a selector outputs. This alternative works only in combination with a selector
bridge. bridge.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 8 E.Mannie, D.Papadimitriou et al.- Standards Track 9
4.9 Recovery GMPLS Nodes 4.9 Recovery GMPLS Nodes
This section defines the GMPLS nodes involved during recovery. This section defines the GMPLS nodes involved during recovery.
A. Ingress GMPLS node of an end-to-end LSP/segment LSP/span A. Ingress GMPLS node of an end-to-end LSP/segment LSP/span
The ingress node of an end-to-end LSP/segment LSP/span is where the The ingress node of an end-to-end LSP/segment LSP/span is where the
normal traffic may be bridged to the recovery end-to-end LSP/segment normal traffic may be bridged to the recovery end-to-end LSP/segment
LSP/span. Also known as source node in the ITU-T terminology. LSP/span. Also known as source node in the ITU-T terminology.
skipping to change at line 440 skipping to change at line 494
normal traffic may be selected from either the working or the normal traffic may be selected from either the working or the
recovery end-to-end LSP/segment LSP/span. Also known as sink node in recovery end-to-end LSP/segment LSP/span. Also known as sink node in
the ITU-T terminology. the ITU-T terminology.
C. Intermediate GMPLS node of an end-to-end LSP/segment LSP C. Intermediate GMPLS node of an end-to-end LSP/segment LSP
A node along either the working or recovery end-to-end LSP/segment A node along either the working or recovery end-to-end LSP/segment
LSP route between the corresponding ingress and egress nodes. Also LSP route between the corresponding ingress and egress nodes. Also
known as intermediate node in the ITU-T terminology. known as intermediate node in the ITU-T terminology.
4.10 Switching Mechanism 4.10 Switch-over Mechanism
A switch is an action that can be performed at both the bridge and A switch-over is an action that can be performed at both the bridge
the selector. This action is as follows: and the selector. This action is as follows:
A. For the selector: A. For the selector:
The action of selecting normal traffic from the recovery LSP/span The action of selecting normal traffic from the recovery LSP/span
rather than from the working LSP/span. rather than from the working LSP/span.
B. For the bridge: B. For the bridge:
In case of permanent connection to the working LSP/span, the action In case of permanent connection to the working LSP/span, the action
of connecting or disconnecting the normal traffic to the recovery of connecting or disconnecting the normal traffic to the recovery
LSP/span. In case of non-permanent connection to the working LSP/span. In case of non-permanent connection to the working
LSP/span, the action of connecting the normal traffic to the LSP/span, the action of connecting the normal traffic to the
recovery LSP/span. recovery LSP/span.
4.11 Reversion operations 4.11 Reversion operations
A revertive recovery operation refers to a recovery switching A revertive recovery operation refers to a recovery switching
operation, where the traffic returns to (or remains on) the working operation, where the traffic returns to (or remains on) the working
LSP/span if the switch requests are terminated; i.e. when the LSP/span if the switch-over requests are terminated; i.e. when the
working LSP/span has recovered from the failure. working LSP/span has recovered from the failure.
Therefore a non-revertive recovery switching operation is when the Therefore a non-revertive recovery switching operation is when the
traffic does not return to the working LSP/span if the switch traffic does not return to the working LSP/span if the switch-over
requests are terminated. requests are terminated.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 9 E.Mannie, D.Papadimitriou et al.- Standards Track 10
4.12 Failure Reporting 4.12 Failure Reporting
This section gives (for information) several signal types commonly This section gives (for information) several signal types commonly
used in transport planes to report a failure condition. Note that used in transport planes to report a failure condition. Note that
fault reporting may require additional signaling mechanisms. fault reporting may require additional signaling mechanisms.
A. Signal Degrade (SD): a signal indicating that the associated data A. Signal Degrade (SD): a signal indicating that the associated data
has degraded. has degraded.
skipping to change at line 507 skipping to change at line 561
A. Lockout of recovery LSP/span: A. Lockout of recovery LSP/span:
A configuration action initiated externally that results in the A configuration action initiated externally that results in the
recovery LSP/span being temporarily unavailable to transport traffic recovery LSP/span being temporarily unavailable to transport traffic
(either normal or extra traffic). (either normal or extra traffic).
B. Lockout of normal traffic: B. Lockout of normal traffic:
A configuration action initiated externally that results in the A configuration action initiated externally that results in the
normal traffic being temporarily not allowed to be routed over its normal traffic being temporarily not allowed to be routed over its
recovery LSP/span. recovery LSP/span. Note that in this case extra-traffic is still
allowed on the recovery LSP/span.
C. Freeze: C. Freeze:
A configuration action initiated externally that prevents any switch A configuration action initiated externally that prevents any
action to be taken, and as such freezes the current state. switch-over action to be taken, and as such freezes the current
state.
D. Forced switch for normal traffic: D. Forced switch-over for normal traffic:
A switch action initiated externally that switches normal traffic to A switch-over action initiated externally that switches normal
the recovery LSP/span, unless an equal or higher priority switch traffic to the recovery LSP/span, unless an equal or higher priority
command is in effect. switch-over command is in effect.
E. Manual switch for normal traffic: E. Manual switch-over for normal traffic:
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 10 E.Mannie, D.Papadimitriou et al.- Standards Track 11
A switch action initiated externally that switches normal traffic to A switch-over action initiated externally that switches normal
the recovery LSP/span, unless a fault condition exists on other traffic to the recovery LSP/span, unless a fault condition exists on
LSPs/spans (including the recovery LSP/span) or an equal or higher other LSPs/spans (including the recovery LSP/span) or an equal or
priority switch command is in effect. higher priority switch-over command is in effect.
F. Manual switch for recovery LSP/span: F. Manual switch-over for recovery LSP/span:
A switch action initiated externally that switches normal traffic to A switch-over action initiated externally that switches normal
the working LSP/span, unless a fault condition exists on the working traffic to the working LSP/span, unless a fault condition exists on
LSP/span or an equal or higher priority switch command is in effect. the working LSP/span or an equal or higher priority switch-over
command is in effect.
G. Clear: G. Clear:
An action initiated externally that clears the active external An action initiated externally that clears the active external
command. command.
4.14 Unidirectional versus Bi-Directional Recovery Switching 4.14 Unidirectional versus Bi-Directional Recovery Switching
A. Unidirectional recovery switching: A. Unidirectional recovery switching:
A recovery switching mode in which, for a unidirectional fault (i.e. A recovery switching mode in which, for a unidirectional fault (i.e.
a fault affecting only one direction of transmission), only the a fault affecting only one direction of transmission), only the
normal traffic transported in the affected direction (of the LSP or normal traffic transported in the affected direction (of the LSP or
skipping to change at line 573 skipping to change at line 631
is greater than 1 one refers to partial span recovery. is greater than 1 one refers to partial span recovery.
A. Full Span Recovery A. Full Span Recovery
All the S LSP carried over a given span are recovered under span All the S LSP carried over a given span are recovered under span
failure condition. Full span recovery is also referred to as "bulk failure condition. Full span recovery is also referred to as "bulk
recovery". recovery".
B. Partial Span Recovery B. Partial Span Recovery
E.Mannie, D.Papadimitriou et al.- Standards Track 12
Only a subset s of the S LSP carried over a given span are recovered Only a subset s of the S LSP carried over a given span are recovered
under span failure condition. Both selection criteria of the under span failure condition. Both selection criteria of the
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 11
entities belonging to this subset and the decision concerning the entities belonging to this subset and the decision concerning the
recovery of the remaining (S - s) LSP are based on local policy. recovery of the remaining (S - s) LSP are based on local policy.
4.16 Recovery Schemes Related Time and Durations 4.16 Recovery Schemes Related Time and Durations
This section gives several typical timing definitions that are of This section gives several typical timing definitions that are of
importance for recovery schemes. importance for recovery schemes.
A. Detection time: A. Detection time:
The time between the occurrence of the fault or degradation and its The time between the occurrence of the fault or degradation and its
detection. Note that this is a rather theoretical time since in detection. Note that this is a rather theoretical time since in
practice this is difficult to measure. practice this is difficult to measure.
B. Correlation time: B. Correlation time:
The time between detection of the fault or degradation and the The time between the detection of the fault or degradation and the
reporting of the signal fail or degrade. This time is typically used reporting of the signal fail or degrade. This time is typically used
in correlating related failures or degradations. in correlating related failures or degradations.
C. Hold-off time: C. Notification time:
The time between reporting of signal fail or degrade, and the The time between the reporting of the signal fail or degrade and the
initialization of the recovery switching algorithm. This is useful reception of the indication of this event by the entities that
when multiple layers of recovery are being used. decide on the recovery switching operation(s).
D. Wait To Restore time: D. Recovery Switching time:
A period of time that must elapse from a recovered fault before an The time between the initialization of the recovery switching
LSP/span can be used again to transport the normal traffic and/or to operation and the moment the normal traffic is selected from the
select the normal traffic from. recovery LSP/span.
E. Switching time: E. Total Recovery time:
The time between the initialization of the recovery switching The total recovery time is defined as the sum of the detection, the
algorithm and the moment the traffic is selected from the recovery correlation, the notification and the recovery switching time.
LSP/span.
F. Recovery time: F. Wait To Restore time:
The recovery time is defined as the sum of the detection, A period of time that must elapse from a recovered fault before an
correlation, hold-off and switching times. LSP/span can be used again to transport the normal traffic and/or to
select the normal traffic from.
Note: the hold-off time is defined as the time between the reporting
of signal fail or degrade, and the initialization of the recovery
switching operation. This is useful when multiple layers of recovery
are being used.
4.17 Impairment 4.17 Impairment
E.Mannie, D.Papadimitriou et al.- Standards Track 13
A defect or performance degradation, which may lead to SF or SD A defect or performance degradation, which may lead to SF or SD
trigger. trigger.
4.18 Recovery Ratio 4.18 Recovery Ratio
The quotient of the actually recovery bandwidth divided by the The quotient of the actually recovery bandwidth divided by the
traffic bandwidth which is intended to be protected. traffic bandwidth which is intended to be protected.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 12 4.19 Hitless Protection Switch-over
4.19 Hitless Protection Switch
Protection switch, which does not cause data loss, data duplication, Protection switch-over, which does not cause data loss, data
data disorder, or bit errors upon recovery switching action. duplication, data disorder, or bit errors upon recovery switching
action.
4.20 Network Survivability 4.20 Network Survivability
The set of capabilities that allow a network to restore affected The set of capabilities that allow a network to restore affected
traffic in the event of a failure. The degree of survivability is traffic in the event of a failure. The degree of survivability is
determined by the networkĘs capability to survive single and determined by the networkĘs capability to survive single and
multiple failures. multiple failures.
4.21 Survivable Network 4.21 Survivable Network
skipping to change at line 674 skipping to change at line 736
SF or SD trigger to the control plane (through internal interface SF or SD trigger to the control plane (through internal interface
with the transport plane). Thus, failure detection (that should with the transport plane). Thus, failure detection (that should
occur at the transport layer closest to the failure) is the only occur at the transport layer closest to the failure) is the only
phase that can not be achieved by the control plane alone. phase that can not be achieved by the control plane alone.
- Phase 2: Failure Localization (and Isolation) - Phase 2: Failure Localization (and Isolation)
Failure localization provides to the deciding entity information Failure localization provides to the deciding entity information
about the location (and so the identity) of the transport plane about the location (and so the identity) of the transport plane
entity that causes the LSP(s)/span(s) failure. The deciding entity entity that causes the LSP(s)/span(s) failure. The deciding entity
E.Mannie, D.Papadimitriou et al.- Standards Track 14
can then take accurate decision to achieve finer grained recovery can then take accurate decision to achieve finer grained recovery
switching action(s). switching action(s).
- Phase 3: Failure Notification - Phase 3: Failure Notification
Failure notification phase is used 1) to inform intermediate nodes Failure notification phase is used 1) to inform intermediate nodes
that LSP(s)/span(s) failure has occurred and has been detected 2) to that LSP(s)/span(s) failure has occurred and has been detected 2) to
inform the recovery deciding entities (which can correspond to any inform the recovery deciding entities (which can correspond to any
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 13
intermediate or end-point of the failed LSP/span) that the intermediate or end-point of the failed LSP/span) that the
corresponding LSP/span is not available. corresponding LSP/span is not available.
- Phase 4: Recovery (Protection or Restoration) - Phase 4: Recovery (Protection or Restoration)
See above. See Section 4.3.
- Phase 5: Reversion (Normalization) - Phase 5: Reversion (Normalization)
See above. See Section 4.11.
The combination of Failure Detection and Failure Localization and The combination of Failure Detection and Failure Localization and
Notification is referred to as Fault Management. Notification is referred to as Fault Management.
5.1 Entities Involved During Recovery 5.1 Entities Involved During Recovery
The entities involved during the recovery operations can be defined The entities involved during the recovery operations can be defined
as follows; these entities are parts of ingress, egress and as follows; these entities are parts of ingress, egress and
intermediate nodes as defined previously: intermediate nodes as defined previously:
skipping to change at line 718 skipping to change at line 780
B. Reporting Entity (Failure Correlation and Notification): B. Reporting Entity (Failure Correlation and Notification):
An entity that can make an intelligent decision on fault correlation An entity that can make an intelligent decision on fault correlation
and report the failure to the deciding entity. Fault reporting can and report the failure to the deciding entity. Fault reporting can
be automatically performed by the deciding entity detecting the be automatically performed by the deciding entity detecting the
failure. failure.
C. Deciding Entity (part of the failure recovery decision process): C. Deciding Entity (part of the failure recovery decision process):
An entity that makes the recovery decision or select the recovery An entity that makes the recovery decision or selects the recovery
resources. This entity communicates the decision to the impacted resources. This entity communicates the decision to the impacted
LSPs/spans with the recovery actions to be performed. LSPs/spans with the recovery actions to be performed.
D. Recovering Entity (part of the failure recovery activation D. Recovering Entity (part of the failure recovery activation
process): process):
An entity that participates in the recovery of the LSPs/spans. An entity that participates in the recovery of the LSPs/spans.
E.Mannie, D.Papadimitriou et al.- Standards Track 15
The process of moving failed LSPs from a failed (working) span to a The process of moving failed LSPs from a failed (working) span to a
protection span must be initiated by one of the nodes terminating protection span must be initiated by one of the nodes terminating
the span, e.g. A or B. The deciding (and recovering) entity is the span, e.g. A or B. The deciding (and recovering) entity is
referred to as the "master" while the other node is called the referred to as the "master" while the other node is called the
"slave" and corresponds to a recovering only entity. "slave" and corresponds to a recovering only entity.
Note: The determination of the master and the slave may be based on Note: The determination of the master and the slave may be based on
configured information or protocol specific requirements. configured information or protocol specific requirements.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 14
6. Protection Schemes 6. Protection Schemes
This section clarifies the multiple possible protection schemes and This section clarifies the multiple possible protection schemes and
the specific terminology for the protection. the specific terminology for the protection.
6.1 1+1 protection 6.1 1+1 Protection
1+1 protection has one working LSP/span, one protection LSP/span and 1+1 protection has one working LSP/span, one protection LSP/span and
a permanent bridge. At the ingress node, the normal traffic is a permanent bridge. At the ingress node, the normal traffic is
permanently bridged to both the working and protection LSP/span. At permanently bridged to both the working and protection LSP/span. At
the egress node, the normal traffic is selected from the better of the egress node, the normal traffic is selected from the better of
the two LSPs/spans. the two LSPs/spans.
Due to the permanent bridging, the 1+1 protection does not allow an Due to the permanent bridging, the 1+1 protection does not allow an
unprotected extra traffic signal to be provided. unprotected extra traffic signal to be provided.
6.2 1:N (N >= 1) Protection 6.2 1:N (N >= 1) Protection
1:N protection has N working LSPs/spans carrying normal traffic and 1:N protection has N working LSPs/spans carrying normal traffic and
1 protecting LSP/span that may carry extra-traffic. 1 protection LSP/span that may carry extra-traffic.
At the ingress, normal traffic is either permanently connected to At the ingress, the normal traffic is either permanently connected
its working LSP/span and may be connected to the protection LSP/span to its working LSP/span and may be connected to the protection
(case of broadcast bridge), or is connected to either its working or LSP/span (case of broadcast bridge), or is connected to either its
the protection LSP/span (case of selector bridge). At the egress working or the protection LSP/span (case of selector bridge). At the
node, the normal traffic is selected from either its working or egress node, the normal traffic is selected from either its working
protection LSP/span. or protection LSP/span.
Unprotected extra traffic can be transported over the protection Unprotected extra traffic can be transported over the protection
LSP/span whenever the protection LSP/span is not used to carry a LSP/span whenever the protection LSP/span is not used to carry a
normal traffic. normal traffic.
6.3 M:N (M, N > 1, M =< N) Protection 6.3 M:N (M, N > 1, N >= M) Protection
M:N protection has N working LSPs/spans carrying normal traffic and M:N protection has N working LSPs/spans carrying normal traffic and
M protecting LSP/span that may carry extra-traffic. M protection LSP/span that may carry extra-traffic.
At the ingress, a normal traffic is either permanently connected to At the ingress, the normal traffic is either permanently connected
its working LSP/span and may be connected to one of the protection to its working LSP/span and may be connected to one of the
LSPs/spans (case of broadcast bridge), or is connected to either its protection LSPs/spans (case of broadcast bridge), or is connected to
working or one of the protection LSPs/spans (case of selector either its working or one of the protection LSPs/spans (case of
bridge). At the egress node, the normal traffic is selected from selector bridge). At the egress node, the normal traffic is selected
either its working or one of the protection LSP/span. from either its working or one of the protection LSP/span.
E.Mannie, D.Papadimitriou et al.- Standards Track 16
Unprotected extra traffic can be transported over the M protection Unprotected extra traffic can be transported over the M protection
LSP/span whenever the protection LSPs/spans is not used to carry a LSP/span whenever the protection LSPs/spans is not used to carry a
normal traffic. normal traffic.
Note1: all protection types are either uni- or bi-directional, 6.4 Notes on Protection Schemes
obviously, the latter applies only to bi-directional LSP/span and
requires coordination between the ingress and egress node during
protection switching.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 15 All protection types are either uni- or bi-directional, obviously,
Note2: all protection types except 1+1 unidirectional protection the latter applies only to bi-directional LSP/span and requires
switching require a communication channel between the ingress and coordination between the ingress and egress node during protection
the egress node. switching.
Note3: in the GMPLS context, span protection refers to the full or All protection types except 1+1 unidirectional protection switching
partial span recovery of the LSPs carried over that span (see require a communication channel between the ingress and the egress
Section 4.15). node.
In the GMPLS context, span protection refers to the full or partial
span recovery of the LSPs carried over that span (see Section 4.15).
7. Restoration Schemes 7. Restoration Schemes
This section clarifies the multiple possible restoration schemes and This section clarifies the multiple possible restoration schemes and
the specific terminology for the restoration. the specific terminology for the restoration.
7.1 Pre-planned LSP Restoration 7.1 Pre-planned LSP Restoration
Also referred to as pre-planned LSP re-routing. Before failure Also referred to as pre-planned LSP re-routing. Before failure
detection and/or notification, one or more restoration LSPs are detection and/or notification, one or more restoration LSPs are
skipping to change at line 832 skipping to change at line 894
Note: when each working LSP is recoverable by exactly one Note: when each working LSP is recoverable by exactly one
restoration LSP, one refers also to 1:1 (pre-planned) re-routing restoration LSP, one refers also to 1:1 (pre-planned) re-routing
without extra-traffic. without extra-traffic.
7.1.1 Shared-Mesh Restoration 7.1.1 Shared-Mesh Restoration
"Shared-mesh" restoration is defined as a particular case of pre- "Shared-mesh" restoration is defined as a particular case of pre-
planned LSP re-routing that reduces the restoration resource planned LSP re-routing that reduces the restoration resource
requirements by allowing multiple restoration LSPs (initiated from requirements by allowing multiple restoration LSPs (initiated from
E.Mannie, D.Papadimitriou et al.- Standards Track 17
distinct ingress nodes) to share common resources (including links distinct ingress nodes) to share common resources (including links
and nodes.) and nodes.)
7.2 LSP Restoration 7.2 LSP Restoration
Also referred to as LSP re-routing. The ingress node switches the Also referred to as LSP re-routing. The ingress node switches the
normal traffic to an alternate LSP signaled and fully established normal traffic to an alternate LSP signaled and fully established
(i.e. cross-connected) after failure detection and/or notification. (i.e. cross-connected) after failure detection and/or notification.
The alternate LSP path may be computed after failure detection The alternate LSP path may be computed after failure detection
and/or notification. In this case, one also refers to "Full LSP Re- and/or notification. In this case, one also refers to "Full LSP Re-
routing." routing."
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 16
The alternate LSP is signaled from the ingress node and may reuse The alternate LSP is signaled from the ingress node and may reuse
intermediate node's resources of the working LSP under failure intermediate node's resources of the working LSP under failure
condition (and may also include additional intermediate nodes.) condition (and may also include additional intermediate nodes.)
7.2.1 Hard LSP Restoration 7.2.1 Hard LSP Restoration
Also referred to as hard LSP re-routing. A re-routing operation Also referred to as hard LSP re-routing. A re-routing operation
where the LSP is released before the full establishment of an where the LSP is released before the full establishment of an
alternate LSP (i.e. break-before-make). alternate LSP (i.e. break-before-make).
skipping to change at line 866 skipping to change at line 929
Also referred to as soft LSP re-routing. A re-routing operation Also referred to as soft LSP re-routing. A re-routing operation
where the LSP is released after the full establishment of an where the LSP is released after the full establishment of an
alternate LSP (i.e. make-before-break). alternate LSP (i.e. make-before-break).
8. Security Considerations 8. Security Considerations
This document does not introduce or imply any specific security This document does not introduce or imply any specific security
consideration. consideration.
9. Intellectual Property Considerations 9. Intellectual Property Consideration
This section is taken from Section 10.4 of [RFC2026].
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed
pertain to the implementation or use of the technology described in to pertain to the implementation or use of the technology
this document or the extent to which any license under such rights described in this document or the extent to which any license
might or might not be available; neither does it represent that it under such rights might or might not be available; nor does it
has made any effort to identify any such rights. Information on the represent that it has made any independent effort to identify any
IETF's procedures with respect to rights in standards-track and such rights. Information on the procedures with respect to rights
standards-related documentation can be found in BCP-11. Copies of in RFC documents can be found in BCP 78 and BCP 79.
claims of rights made available for publication 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 implementors or users of this specification
can be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any Copies of IPR disclosures made to the IETF Secretariat and any
copyrights, patents or patent applications, or other proprietary assurances of licenses to be made available, or the result of an
rights, which may cover technology that may be required to practice attempt made to obtain a general license or permission for the use
this standard. Please address the information to the IETF Executive of such proprietary rights by implementers or users of this
Director. specification can be obtained from the IETF on-line IPR repository
at http://www.ietf.org/ipr.
10. References E.Mannie, D.Papadimitriou et al.- Standards Track 18
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.
10.1 Normative References 9.1 IPR Disclosure Acknowledgement
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 17 By submitting this Internet-Draft, I certify that any applicable
[G.707] ITU-T, "Network Node Interface for the Synchronous patent or other IPR claims of which I am aware have been
Digital Hierarchy (SDH)," Recommendation G.707, October disclosed, and any of which I become aware will be disclosed, in
2000. accordance with RFC 3668.
[G.841] ITU-T, "Types and Characteristics of SDH Network 10. References
Protection Architectures," Recommendation G.841,
October 1998.
[G.842] ITU-T, "Interworking of SDH network protection 10.1 Normative References
architectures," Recommendation G.842, October 1998.
[RFC-2026] S.Bradner, "The Internet Standards Process -- Revision [RFC2026] S.Bradner, "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996. 3", BCP 9, RFC 2026, October 1996.
[RFC-2119] S.Bradner, "Key words for use in RFCs to Indicate [RFC2119] S.Bradner, "Key words for use in RFCs to Indicate
Requirement Levels," BCP 14, RFC 2119, March 1997. Requirement Levels," BCP 14, RFC 2119, March 1997.
[T1.105] ANSI, "Synchronous Optical Network (SONET): Basic
Description Including Multiplex Structure, Rates, and
Formats," ANSI T1.105, January 2001.
10.2 Informative References 10.2 Informative References
[BALA] B.Rajagopalan et al., "Signaling for Protection and [G.707] ITU-T, "Network Node Interface for the Synchronous
Restoration in Optical Mesh Networks," Internet Draft, Digital Hierarchy (SDH)," Recommendation G.707, October
Work in progress, draft-bala-protection-restoration- 2000.
signaling-00.txt.
[G.783] ITU-T, "Characteristics of Synchronous Digital [G.783] ITU-T, "Characteristics of Synchronous Digital
Hierarchy (SDH) Equipment Functional Blocks," Hierarchy (SDH) Equipment Functional Blocks,"
Recommendation G.783, October 2000. Recommendation G.783, October 2000.
[G.806] ITU-T, "Characteristics of Transport Equipment ū [G.806] ITU-T, "Characteristics of Transport Equipment
Description Methodology and Generic Functionality," Description Methodology and Generic Functionality,"
Recommendation G.806, October 2000. Recommendation G.806, October 2000.
[G.808.1] ITU-T, "Generic Protection Switching ū Linear trail and [G.808.1] ITU-T, "Generic Protection Switching Linear trail and
subnetwork protection," Draft Recommendation (work in subnetwork protection," Recommendation G.808.1,
progress), Version 0.5, January 2003. December 2003.
[G.841] ITU-T, "Types and Characteristics of SDH Network
Protection Architectures," Recommendation G.841,
October 1998.
[G.842] ITU-T, "Interworking of SDH network protection
architectures," Recommendation G.842, October 1998.
[GMPLS-ARCH] E.Mannie (Editor), "Generalized MPLS Architecture," [GMPLS-ARCH] E.Mannie (Editor), "Generalized MPLS Architecture,"
Internet Draft, Work in progress, draft-ietf-ccamp- Internet Draft, Work in progress, draft-ietf-ccamp-
gmpls-architecture-06.txt, April 2003. gmpls-architecture-07.txt, May 2003.
[SUDHEER] S.Dharanikota et al., "NNI Protection and restoration
requirements," OIF Contribution 507, 2001.
[TEWG] W.S.Lai, et al., "Network Hierarchy and Multilayer E.Mannie, D.Papadimitriou et al.- Standards Track 19
Survivability," Internet Draft, Work in progress, [RFC3386] W.S.Lai, et al., "Network Hierarchy and Multilayer
draft-ietf-tewg-restore-hierarchy-01.txt, June 2002. Survivability," RFC 3386, November 2002.
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 18 [T1.105] ANSI, "Synchronous Optical Network (SONET): Basic
Description Including Multiplex Structure, Rates, and
Formats," ANSI T1.105, January 2001.
11. Acknowledgments 11. Acknowledgments
Valuable comments and input were received from many people. Many thanks to Adrian Farrel for having thoroughly review this
document.
12. Author's Addresses 12. Editor's Addresses
Eric Mannie (Consult) Eric Mannie
Email: eric_mannie@hotmail.com EMail: eric_mannie@hotmail.com
Dimitri Papadimitriou (Alcatel) Dimitri Papadimitriou (Alcatel)
Francis Wellesplein, 1 Francis Wellesplein, 1
B-2018 Antwerpen, Belgium B-2018 Antwerpen, Belgium
Phone: +32 3 240-8491 Phone: +32 3 240-8491
Email: dimitri.papadimitriou@alcatel.be EMail: dimitri.papadimitriou@alcatel.be
E.Mannie, D.Papadimitriou et al.- Internet Draft - June 2004 19 E.Mannie, D.Papadimitriou et al.- Standards Track 20
Full Copyright Statement Full Copyright Statement
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