Internet DRAFT - draft-ietf-teas-gmpls-signaling-smp
draft-ietf-teas-gmpls-signaling-smp
TEAS Working Group J. He
Internet-Draft I. Busi
Updates: 4872, 4873 (if approved) Huawei Technologies
Intended status: Standards Track J. Ryoo
Expires: October 21, 2022 B. Yoon
ETRI
P. Park
KT
April 19, 2022
GMPLS Signaling Extensions for Shared Mesh Protection
draft-ietf-teas-gmpls-signaling-smp-12
Abstract
ITU-T Recommendation G.808.3 defines the generic aspects of a Shared
Mesh Protection (SMP) mechanism, where the difference between SMP and
Shared Mesh Restoration (SMR) is also identified. ITU-T
Recommendation G.873.3 defines the protection switching operation and
associated protocol for SMP at the Optical Data Unit (ODU) layer.
RFC 7412 provides requirements for any mechanism that would be used
to implement SMP in a Multi-Protocol Label Switching - Transport
Profile (MPLS-TP) network.
This document updates RFC 4872 and RFC 4873 to provide the extensions
to the Generalized Multi-Protocol Label Switching (GMPLS) signaling
to support the control of the SMP.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 21, 2022.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. SMP Definition . . . . . . . . . . . . . . . . . . . . . . . 4
4. Operation of SMP with GMPLS Signaling Extension . . . . . . . 5
5. GMPLS Signaling Extension for SMP . . . . . . . . . . . . . . 6
5.1. Identifiers . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. Signaling Primary LSPs . . . . . . . . . . . . . . . . . 7
5.3. Signaling Secondary LSPs . . . . . . . . . . . . . . . . 7
5.4. SMP Preemption Priority . . . . . . . . . . . . . . . . . 8
5.5. Notifying Availability of Shared Resources . . . . . . . 8
5.6. SMP APS Configuration . . . . . . . . . . . . . . . . . . 9
6. Updates to PROTECTION Object . . . . . . . . . . . . . . . . 10
6.1. New Protection Type . . . . . . . . . . . . . . . . . . . 10
6.2. Updates on Notification and Operational Bits . . . . . . 10
6.3. Preemption Priority . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
10. Contributor . . . . . . . . . . . . . . . . . . . . . . . . . 12
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11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
11.1. Normative References . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
RFC 4872 [RFC4872] defines extension of Resource Reservation Protocol
- Traffic Engineering (RSVP-TE) to support Shared Mesh Restoration
(SMR) mechanisms. SMR can be seen as a particular case of pre-
planned Label Switched Path (LSP) rerouting that reduces the recovery
resource requirements by allowing multiple protecting LSPs to share
common link and node resources. The recovery resources for the
protecting LSPs are pre-reserved during the provisioning phase, and
explicit restoration signaling is required to activate (i.e., commit
resource allocation at the data plane) a specific protecting LSP that
was instantiated during the provisioning phase. RFC 4873 [RFC4873]
details the encoding of the last 32-bit Reserved field of the
PROTECTION object defined in [RFC4872]
ITU-T Recommendation G.808.3 [G808.3] defines the generic aspects of
a shared mesh protection (SMP) mechanism, which are not specific to a
particular network technology in terms of architecture types,
preemption principle, and path monitoring methods, etc. ITU-T
Recommendation G.873.3 [G873.3] defines the protection switching
operation and associated protocol for SMP at the Optical Data Unit
(ODU) layer. RFC 7412 [RFC7412] provides requirements for any
mechanism that would be used to implement SMP in a Multi-Protocol
Label Switching - Transport Profile (MPLS-TP) network.
SMP differs from SMR in the activation/protection switching
operation. The former activates a protecting LSP via the automatic
protection switching (APS) protocol in the data plane when the
working LSP fails, while the latter does it via control plane
signaling. It is therefore necessary to distinguish SMP from SMR
during provisioning so that each node involved behaves appropriately
in the recovery phase when activation of a protecting LSP is done.
SMP has advantages with regard to the recovery speed compared with
SMR.
This document updates [RFC4872] and [RFC4873] to provide the
extensions to the Generalized Multi-Protocol Label Switching (GMPLS)
signaling to support the control of the SMP mechanism. Specifically,
it;
o defines a new LSP protection type, "Shared Mesh Protection," for
the LSP Flags field [RFC4872] of the PROTECTION object (see
Section 6.1),
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o updates the definitions of the Notification (N) and Operational
(O) fields [RFC4872] of the PROTECTION object to take the new SMP
type into account (see Section 6.2), and
o updates the definition of the 16-bit Reserved field [RFC4873] of
the PROTECTION object to allocate 8 bits to signal the SMP
preemption priority (see Section 6.3).
Only the generic aspects for signaling SMP are addressed by this
document. The technology-specific aspects are expected to be
addressed by other documents.
RFC 8776 [RFC8776] defines a collection of common YANG data types for
Traffic Engineering (TE) configuration and state capabilities. It
defines several identities for LSP protection types. As this
document introduces a new LSP Protection Type, [RFC8776] is expected
to be updated to support the SMP specified in this document.
[I-D.ietf-teas-yang-te] defines a YANG data model for the
provisioning and management of TE tunnels, LSPs, and interfaces. It
includes some protection and restoration data nodes relevant to this
document. Management aspects of the SMP are outside the scope of
this document, and they are expected to be addressed by other
documents.
2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
In addition, the reader is assumed to be familiar with the
terminology used in [RFC4872], RFC 4426 [RFC4426], and RFC 6372
[RFC6372].
3. SMP Definition
[G808.3] defines the generic aspects of an SMP mechanism. [G873.3]
defines the protection switching operation and associated protocol
for SMP at the ODU layer. [RFC7412] provides requirements for any
mechanism that would be used to implement SMP in a MPLS-TP network.
The SMP mechanism is based on pre-computed protecting LSPs that are
pre-configured into the network elements. Pre-configuration here
means pre-reserving resources for the protecting LSPs without
activating a particular protecting LSP (e.g., in circuit networks,
the cross-connects in the intermediate nodes of the protecting LSP
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are not pre-established). Pre-configuring but not activating
protecting LSPs allows link and node resources to be shared by the
protecting LSPs of multiple working LSPs (that are themselves
disjoint and thus unlikely to fail simultaneously). Protecting LSPs
are activated in response to failures of working LSPs or operator's
commands by means of the APS protocol that operates in the data
plane. The APS protocol messages are exchanged along the protecting
LSP. SMP is always revertive.
SMP has a lot of similarity to SMR except that the activation in case
of SMR is achieved by control plane signaling during the recovery
operation, while SMP is done by the APS protocol in the data plane.
4. Operation of SMP with GMPLS Signaling Extension
Consider the following network topology:
A---B---C---D
\ /
E---F---G
/ \
H---I---J---K
Figure 1: An example of SMP topology
The working LSPs [A,B,C,D] and [H,I,J,K] could be protected by the
protecting LSPs [A,E,F,G,D] and [H,E,F,G,K], respectively. Per RFC
3209 [RFC3209], in order to achieve resource sharing during the
signaling of these protecting LSPs, they MUST have the same Tunnel
Endpoint Address (as part of their SESSION object). However, these
addresses are not the same in this example. Similar to SMR, this
document defines a new LSP Protection Type of the secondary LSP as
"Shared Mesh Protection" (see Section 6.1) to allow resource sharing
along nodes E, F, and G. Examples of shared resources include the
capacity of a link and the cross-connects in a node. In this case,
the protecting LSPs are not merged (which is useful since the paths
diverge at G), but the resources along E, F, G can be shared.
When a failure, such as Signal Fail (SF) and Signal Degrade (SD),
occurs on one of the working LSPs (say working LSP [A,B,C,D]), the
end node (say node A) that detects the failure initiates the
protection switching operation. End node A will send a protection
switching request APS message (for example, SF) to its adjacent
(downstream) intermediate node (say node E) to activate the
corresponding protecting LSP and will wait for a confirmation message
from node E.
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If the protection resource is available, node E will send the
confirmation APS message to the end node A and forward the switching
request APS message to its adjacent (downstream) node (say node F).
When the confirmation APS message is received by node A, the cross-
connection on node A is established. At this time traffic is bridged
to and selected from the protecting LSP at node A. After forwarding
the switching request APS message, node E will wait for a
confirmation APS message from node F, which triggers node E to set up
the cross-connection for the protecting LSP being activated.
If the protection resource is not available (due to failure or being
used by higher priority connections), the switching will not be
successful; the intermediate node (node E) MUST send a message to
notify the end node (node A) (see Section 5.5). If the resource is
in use by a lower priority protecting LSP, the lower priority service
will be removed and then the intermediate node will follow the
procedure as described for the case when the protection resource is
available for the higher priority protecting LSP.
If node E fails to allocate the protection resource, it MUST send a
message to notify node A (see Section 5.5). Then, node A will stop
bridging and selecting traffic to/from the protecting LSP and proceed
with the procedure of removing the protection allocation according to
the APS protocol.
5. GMPLS Signaling Extension for SMP
The following subsections detail how LSPs using SMP can be signaled
in an interoperable fashion using GMPLS RSVP-TE extensions (see RFC
3473 [RFC3473]). This signaling enables:
(1) the ability to identify a "secondary protecting LSP" (LSP
[A,E,F,G,D] or LSP [H,E,F,G,K] from Figure 1, hereby called the
"secondary LSP") used to recover another "primary working LSP"
(LSP [A,B,C,D] or LSP [H,I,J,K] from Figure 1, hereby called the
"protected LSP"),
(2) the ability to associate the secondary LSP with the protected
LSP,
(3) the capability to include information about the resources used
by the protected LSP while instantiating the secondary LSP,
(4) the capability to instantiate during the provisioning phase
several secondary LSPs efficiently, and
(5) the capability to support activation of a secondary LSP after
failure occurrence via APS protocol in the data plane.
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5.1. Identifiers
To simplify association operations, both LSPs (i.e., the protected
and the secondary LSPs) belong to the same session. Thus, the
SESSION object MUST be the same for both LSPs. The LSP ID, however,
MUST be different to distinguish between the protected LSP and the
secondary LSP.
A new LSP Protection Type "Shared Mesh Protection" is defined (see
Section 6.1) for the LSP Flags of PROTECTION object (see [RFC4872])
to set up the two LSPs. This LSP Protection Type value is applicable
only to bidirectional LSPs as required in [G808.3].
5.2. Signaling Primary LSPs
The PROTECTION object (see [RFC4872]) is included in the Path message
during signaling of the primary working LSPs, with the LSP Protection
Type value set to "Shared Mesh Protection".
Primary working LSPs are signaled by setting in the PROTECTION object
the S bit to 0, the P bit to 0, and the N bit to 1, and in the
ASSOCIATION object, the Association ID to the associated secondary
protecting LSP_ID.
Note: N bit is set to indicate that the protection switching
signaling is done via data plane.
5.3. Signaling Secondary LSPs
The PROTECTION object (see [RFC4872]) is included in the Path message
during signaling of the secondary protecting LSPs, with the LSP
Protection Type value set to "Shared Mesh Protection".
Secondary protecting LSPs are signaled by setting in the PROTECTION
object the S bit, the P bit, and the N bit to 1, and in the
ASSOCIATION object, the Association ID to the associated primary
working LSP_ID, which MUST be known before signaling of the secondary
LSP. Moreover, the Path message used to instantiate the secondary
LSP MUST include at least one PRIMARY_PATH_ROUTE object (see
[RFC4872]) that further allows for recovery resource sharing at each
intermediate node along the secondary path.
With this setting, the resources for the secondary LSP MUST be pre-
reserved, but not committed at the data plane level, meaning that the
internals of the switch need not be established until explicit action
is taken to activate this LSP. Activation of a secondary LSP and
protection switching to the activated protecting LSP is done using
APS protocol in the data plane.
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After protection switching completes the protecting LSP MUST be
signaled with the S bit set to 0 and O bit set to 1 in the PROTECTION
object. At this point, the link and node resources MUST be allocated
for this LSP that becomes a primary LSP (ready to carry traffic).
The formerly working LSP MAY be signaled with the A bit set in the
ADMIN_STATUS object (see [RFC3473]).
Support for extra traffic in SMP is for further study. Therefore,
mechanisms to set up LSPs for extra traffic are outside the scope of
this document.
5.4. SMP Preemption Priority
The SMP preemption priority of a protecting LSP that the APS protocol
uses to resolve the competition for shared resources among multiple
protecting LSPs, is indicated in Preemption Priority field of the
PROTECTION object in the Path message of the protecting LSP.
The Setup and Holding priorities in the SESSION_ATTRIBUTE object can
be used by GMPLS to control LSP preemption, but, they are not used by
the APS to resolve the competition among multiple protecting LSPs.
This avoids the need to define a complex policy for defining Setup
and Holding priorities when used for both GMPLS control plane LSP
preemption and SMP shared resource competition resolution.
When an intermediate node on the protecting LSP receives the Path
message, the priority value in the Preemption Priority field MUST be
stored for that protecting LSP. When resource competition among
multiple protecting LSPs occurs, the APS protocol will use their
priority values to resolve the competition. A lower value has a
higher priority.
In SMP, a preempted LSP MUST NOT be terminated even after its
resources have been deallocated. Once the working LSP and the
protecting LSP are configured or pre-configured, the end node MUST
keep refreshing both working and protecting LSPs regardless of
failure or preempted situation.
5.5. Notifying Availability of Shared Resources
When a lower priority protecting LSP is preempted, the intermediate
node that performed preemption MUST send a Notify message with error
code "Notify Error" (25) (see [RFC4872]) and error sub-code "Shared
resources unavailable" (TBA1) to the end nodes of that protecting
LSP. Upon receipt of this Notify message, the end node MUST stop
sending and selecting traffic to/from its protecting LSP and try
switching the traffic to another protecting LSP, if available.
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When a protecting LSP occupies the shared resources and they become
unavailable, the same Notify message MUST be generated by the
intermediate node to all the end nodes of the protecting LSPs that
have lower SMP preemption priorities than the one that has occupied
the shared resources. In case the shared resources become
unavailable due to a failure in the shared resources, the same Notify
message MUST be generated by the intermediate node to all the end
nodes of the protecting LSPs that have been configured to use the
shared resources. These end nodes, in case of a failure of the
working LSP, MUST avoid trying to switch traffic to these protecting
LSPs that have been configured to use the shared resources and try
switching the traffic to other protecting LSPs, if available.
When the shared resources become available, a Notify message with
error code "Notify Error" (25) and error sub-code "Shared resources
available" (TBA2) MUST be generated by the intermediate node. The
recipients of this Notify message are the end nodes of the lower
priority protecting LSPs that have been preempted and/or all the end
nodes of the protecting LSPs that have lower SMP preemption
priorities than the one that does not need the shared resources
anymore. Upon receipt of this Notify message, the end node is
allowed to reinitiate the protection switching operation as described
in Section 4, if it still needs the protection resource.
5.6. SMP APS Configuration
SMP relies on APS protocol messages being exchanged between the nodes
along the path to activate an SMP protecting LSP.
In order to allow the exchange of APS protocol messages, an APS
channel has to be configured between adjacent nodes along the path of
the SMP protecting LSP. This is done by other means than GMPLS
signaling, before any SMP protecting LSP has been set up. Therefore,
there are likely additional requirements for APS configuration which
are outside the scope of this document.
Depending on the APS protocol message format, the APS protocol may
use different identifiers than GMPLS signaling to identify the SMP
protecting LSP.
Since APS protocol is for further study in [G808.3], it can be
assumed that APS message format and identifiers are technology-
specific and/or vendor-specific. Therefore, additional requirements
for APS configuration are outside the scope of this document.
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6. Updates to PROTECTION Object
GMPLS extension requirements for SMP introduce several updates to the
Protection Object (see [RFC4872]).
6.1. New Protection Type
A new LSP protection type "Shared Mesh Protection" is added in the
PROTECTION object. This LSP Protection Type value is applicable to
only bidirectional LSPs.
LSP (Protection Type) Flags:
0x20: Shared Mesh Protection
The rules defined in Section 14.2 of [RFC4872] ensure that all the
nodes along an SMP LSP are SMP aware. Therefore, there are no
backward compatibility issues.
6.2. Updates on Notification and Operational Bits
The definitions of the N and O bits in Section 14.1 of [RFC4872] are
replaced as follows:
Notification (N): 1 bit
When set to 1, this bit indicates that the control plane message
exchange is only used for notification during protection
switching. When set to 0 (default), it indicates that the control
plane message exchanges are used for protection-switching
purposes. The N bit is only applicable when the LSP Protection
Type Flag is set to 0x04 (1:N Protection with Extra-Traffic), 0x08
(1+1 Unidirectional Protection), 0x10 (1+1 Bidirectional
Protection), or 0x20 (Shared Mesh Protection). The N bit MUST be
set to 0 in any other case. If 0x20 (SMP), the N bit MUST be set
to 1.
Operational (O): 1 bit
When set to 1, this bit indicates that the protecting LSP is
carrying traffic after protection switching. The O bit is only
applicable when the P bit is set to 1, and the LSP Protection Type
Flag is set to 0x04 (1:N Protection with Extra-Traffic), 0x08 (1+1
Unidirectional Protection), 0x10 (1+1 Bidirectional Protection),
or 0x20 (Shared Mesh Protection). The O bit MUST be set to 0 in
any other case.
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6.3. Preemption Priority
[RFC4872] reserved a 32-bit field in the PROTECTION object header.
Subsequently, [RFC4873] allocated several fields from that field, and
left the remainder of the bits reserved. This specification further
allocates the preemption priority field from those formerly-reserved
bits. The 32-bit field in the PROTECTION object defined in [RFC4873]
are updated as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|I|R| Reserved | Seg.Flags | Reserved | Preempt Prio |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Preemption Priority (Preempt Prio): 8 bit
This field indicates the SMP preemption priority of a protecting
LSP, when the LSP Protection Type field indicates "Shared Mesh
Protection". The SMP preemption priority value is configured at
the end nodes of the protecting LSP by a network operator. A
lower value has a higher priority. The decision of how many
priority levels to be operated in an SMP network is a network
operator's choice.
See [RFC4873] for the definition of other fields.
7. IANA Considerations
IANA maintains a registry called "Resource Reservation Protocol
(RSVP) Parameters" with a subregistry called "Error Codes and
Globally-Defined Error Value Sub-Codes". Within this subregistry
there is a definition of the "Notify Error" error code (25). The
definition lists a number of error value sub-codes that may be used
with this error code. IANA is requested to allocate further error
value sub-codes for use with this error code as described in this
document.
Value Description Reference
----- ---------------------------- ---------------
TBA1 Shared resources unavailable (this document)
TBA2 Shared resources available (this document)
8. Security Considerations
Since this document makes use of the exchange of RSVP messages
including a Notify message, the security threats discussed in
[RFC4872] also apply to this document.
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Additionally, it may be possible to cause disruption to traffic on
one protecting LSP by targeting a link used by the primary LSP of
another, higher priority LSP somewhere completely different in the
network. For example, in Figure 1, assume that the preemption
priority of LSP [A,E,F,G,D] is higher than that of LSP [H,E,F,G,K]
and the protecting LSP [H,E,F,G,K] is being used to transport
traffic. If link B-C is attacked, traffic on LSP [H,E,F,G,K] can be
disrupted. For this reason, it is important not only to use security
mechanisms as discussed in [RFC4872] but also to acknowledge that
detailed knowledge of a network's topology, including routes and
priorities of LSPs, can help an attacker better target or improve the
efficacy of an attack.
9. Acknowledgements
The authors would like to thank Adrian Farrel, Vishnu Pavan Beeram,
Tom Petch, Ines Robles, John Scudder, Dale Worley, Dan Romascanu,
Eric Vyncke, Roman Danyliw, Paul Wouters, Lars Eggert, Francesca
Palombini, and Robert Wilton for their valuable comments and
suggestions on this document.
10. Contributor
The following person contributed significantly to the content of this
document and should be considered as a co-author.
Yuji Tochio
Fujitsu
Email: tochio@fujitsu.com
11. References
11.1. Normative References
[G808.3] International Telecommunication Union, "Generic protection
switching - Shared mesh protection", ITU-T Recommendation
G.808.3, October 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
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[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
DOI 10.17487/RFC3473, January 2003,
<https://www.rfc-editor.org/info/rfc3473>.
[RFC4426] Lang, J., Ed., Rajagopalan, B., Ed., and D. Papadimitriou,
Ed., "Generalized Multi-Protocol Label Switching (GMPLS)
Recovery Functional Specification", RFC 4426,
DOI 10.17487/RFC4426, March 2006,
<https://www.rfc-editor.org/info/rfc4426>.
[RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
Ed., "RSVP-TE Extensions in Support of End-to-End
Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
<https://www.rfc-editor.org/info/rfc4872>.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873,
May 2007, <https://www.rfc-editor.org/info/rfc4873>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
11.2. Informative References
[G873.3] International Telecommunication Union, "Optical transport
network - Shared mesh protection", ITU-T Recommendation
G.873.3, September 2017.
[I-D.ietf-teas-yang-te]
Saad, T., Gandhi, R., Liu, X., Beeram, V. P., Bryskin, I.,
and O. G. D. Dios, "A YANG Data Model for Traffic
Engineering Tunnels, Label Switched Paths and Interfaces",
draft-ietf-teas-yang-te-29 (work in progress), February
2022.
[RFC6372] Sprecher, N., Ed. and A. Farrel, Ed., "MPLS Transport
Profile (MPLS-TP) Survivability Framework", RFC 6372,
DOI 10.17487/RFC6372, September 2011,
<https://www.rfc-editor.org/info/rfc6372>.
[RFC7412] Weingarten, Y., Aldrin, S., Pan, P., Ryoo, J., and G.
Mirsky, "Requirements for MPLS Transport Profile (MPLS-TP)
Shared Mesh Protection", RFC 7412, DOI 10.17487/RFC7412,
December 2014, <https://www.rfc-editor.org/info/rfc7412>.
He, et al. Expires October 21, 2022 [Page 13]
Internet-Draft GMPLS Extension for SMP April 2022
[RFC8776] Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
"Common YANG Data Types for Traffic Engineering",
RFC 8776, DOI 10.17487/RFC8776, June 2020,
<https://www.rfc-editor.org/info/rfc8776>.
Authors' Addresses
Jia He
Huawei Technologies
F3-1B, R&D Center, Huawei Industrial Base, Bantian, Longgang District
Shenzhen
China
Email: hejia@huawei.com
Italo Busi
Huawei Technologies
Email: italo.busi@huawei.com
Jeong-dong Ryoo
ETRI
218 Gajeongno
Yuseong-gu, Daejeon 34129
South Korea
Phone: +82-42-860-5384
Email: ryoo@etri.re.kr
Bin Yeong Yoon
ETRI
Email: byyun@etri.re.kr
Peter Park
KT
Email: peter.park@kt.com
He, et al. Expires October 21, 2022 [Page 14]
