Network Working Group J. Dong
Internet-Draft M. Chen
Intended status: Standards Track Huawei Technologies
Expires: November 29, 2012 Z. Li
China Mobile
May 28, 2012
RSVP-TE Extensions for Lock Instruct and Loopback in MPLS Transport
Profile
draft-dong-ccamp-rsvp-te-mpls-tp-li-lb-03
Abstract
This document specifies extensions to RSVP-TE to support lock
instruct and loopback mechanism for MPLS-TP LSPs. The mechanisms are
intended to be applicable to other aspects of MPLS as well.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
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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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 29, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Extensions to RSVP-TE . . . . . . . . . . . . . . . . . . . . . 3
3. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Lock Instruct . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Loopback . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
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1. Introduction
The requirements of Lock Instruct (LI) and Loopback (LB) are
specified in [RFC5860], and the framework of LI and LB is specified
in [RFC6371]. [RFC6435] defines in-band Lock Instruct (LI) and
Loopback (LB) functions, it leverages the Generic Associated Channel
(GACH) and Generic Associated Channel Label (GAL) [RFC5586] and the
management plane to perform LI function, and use management plane to
perform the LB function. In-band LI and LB are suitable for the
scenarios where control plane is not used.
When a control plane is used for establishing MPLS-TP LSPs, it's
natural to use and extend the control plane protocol to implement LI
and LB functions. Since LI and LB would modify the forwarding plane
of an LSP, without the involvement of control plane this may result
in inconsistency of the LSP information between control plane and
data plane. Besides, with control plane mechanisms, it does not need
to rely on the TTL expiration to make the LI/LB commands to reach
particular MIP or MEP.
This document specifies extensions to RSVP-TE to implement LI and LB
for MPLS-TP LSPs when MPLS-TP control plane is used. The mechanisms
defined in this document are complementary to [RFC6435].
2. Extensions to RSVP-TE
The A (Administratively down) bit in ADMIN_STATUS Object [RFC3471]
[RFC3473] is used to indicate the lock/unlock of the LSP. One new
bit is defined in ADMIN_STATUS Object to indicate the loopback mode.
Format of extended ADMIN_STATUS Object is as below:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num(196)| C-Type (1) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R| Reserved |B|H|L|I|C|T|A|D|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Loopback (B): When this bit is set in Notify message sent from the
ingress node, it indicates that the target node of this message
SHOULD perform loopback function for this LSP. When this bit is set
in Notify message sent to the ingress node, it indicates the node
originating this message is in "Loopback" mode.
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Reflect (R): 1 bit - see [RFC3471]
Handover (H): 1 bit - see [RFC5852]
Lockout (L): 1 bit - see [RFC4872]
Inhibit Alarm Indication (I): 1 bit - see [RFC4783]
Call Control (C): 1 bit - see [RFC4974]
Testing (T): 1 bit - see [RFC3471]
Administratively down (A): 1 bit - see [RFC3471]
Deletion in progress (D): 1 bit - see [RFC3471]
3. Operations
3.1. Lock Instruct
When a MEP wants to put an LSP in lock mode, it MUST send a Path
message with the Administratively down (A) bit and the Reflect (R)
bit in ADMIN_STATUS Object set. The intermediate nodes SHOULD
forward the message with the A bit unchanged to the downstream .
On receipt of this Path message, the receiving MEP node SHOULD try to
take the LSP out of service. If the receiving MEP locks the LSP
successfully, it SHOULD send a Resv message with the A bit in
ADMIN_STATUS Object set. Otherwise, it SHOULD send a PathErr message
with the Error Code "OAM Problem" and the new Error Value "Lock
Failure", and the following Resv message SHOULD be sent with the A
bit cleared. Though the intermediate nodes do not need to take
actions during this procedure, they would be aware of whether the LSP
is in Lock mode or not.
When an LSP is put in lock mode, the subsequent Path and Resv
messages SHOULD keep the A bit in ADMIN_STATUS Object set.
When a MEP wants to take the LSP out of the lock mode, it MUST send a
Path message with the A bit cleared. The intermediate nodes do not
need to take action on this message and SHOULD forward it unchanged
to the downstream.
On receipt of this Path message, the receiving MEP node SHOULD try to
bring the LSP back to service. If the receiving MEP unlocks the LSP
successfully, it SHOULD send a Resv message with the A bit in
ADMIN_STATUS Object cleared. Otherwise, it SHOULD send a PathErr
message with the Error Code "OAM Problem" and the new Error Value
"Unlock Failure", and the following Resv message SHOULD be sent with
the A bit set.
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3.2. Loopback
Notify message is used to support signaling of Loopback request.
When a MEP wants to put particular LSR on the given LSP in loopback
mode, it MUST send a Notify message with the Reflect (R) bit, the
Loopback (B) Bit and the Administratively down (A) bit in
ADMIN_STATUS Object set. The destination address of this Notify
message SHOULD be set to the MIP or MEP which is required to loopback
the traffic. The ERROR_SPEC object is not relevant in loopback
request and MUST carry the Error Code zero ("Confirmation") to
indicate that there is no error.
On receipt of this Notify message, the receiver node SHOULD try to
put the LSP in loopback mode. If the receiver node puts the LSP into
loopback mode successfully, it SHOULD send a Notify message back to
the MEP node, with both the Loopback (B) Bit and the Administratively
down (A) bit in ADMIN_STATUS Object set, and the ERROR_SPEC object
MUST carry the Error Code zero. Otherwise, it SHOULD send a Notify
message with the Error Code "OAM Problem" and the new Error Value
"Loopback Failure".
When a MEP wants to take the LSP out of the loopback mode, it MUST
send a Notify message with the Reflect (R) bit and the
Administratively down (A) bit set and the Loopback (B) Bit cleared.
The destination address of this Notify message SHOULD be set to the
MIP or MEP which is performing the loopback action for this LSP.
On receipt of this Notify message, the receiving node SHOULD try to
put the LSP back to normal operation. If the receiving node put the
LSP into normal operation successfully, it SHOULD send a Notify
message back to the MEP node, with the Administratively down (A) Bit
set and the Loopback (B) Bit cleared, and the ERROR_SPEC object MUST
carry the Error Code zero. Otherwise, it SHOULD send a Notify
message with the Error Code "OAM Problem" and the new Error Value
"Exit Loopback Failure".
4. IANA Considerations
One bit ("Loopback" (B)) needs to be allocated in the ADMIN_STATUS
Object.
Four new Error Values need to be allocated for Error Code "OAM
Problem": "Lock Failure", "Unlock Failure", "Loopback Failure", "Exit
Loopback Failure".
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5. Security Considerations
This document does not introduce any new security issues above those
identified in [RFC3209] and [RFC3473].
6. Acknowledgements
The authors would like to thank Greg Mirsky, Lou Berger and Francesco
Fondelli for their comments and suggestions.
7. References
7.1. Normative References
[I-D.ietf-ccamp-oam-configuration-fwk]
Takacs, A., Fedyk, D., and H. Jia, "GMPLS RSVP-TE
extensions for OAM Configuration",
draft-ietf-ccamp-oam-configuration-fwk-07 (work in
progress), January 2012.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004.
[RFC5586] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic
Associated Channel", RFC 5586, June 2009.
[RFC5860] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Operations, Administration, and Maintenance (OAM) in MPLS
Transport Networks", RFC 5860, May 2010.
[RFC6371] Busi, I. and D. Allan, "Operations, Administration, and
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Maintenance Framework for MPLS-Based Transport Networks",
RFC 6371, September 2011.
7.2. Informative References
[I-D.ietf-ccamp-rsvp-te-mpls-tp-oam-ext]
Bellagamba, E., Andersson, L., Skoldstrom, P., Ward, D.,
and A. Takacs, "Configuration of Pro-Active Operations,
Administration, and Maintenance (OAM) Functions for MPLS-
based Transport Networks using RSVP-TE",
draft-ietf-ccamp-rsvp-te-mpls-tp-oam-ext-08 (work in
progress), April 2012.
[RFC4974] Papadimitriou, D. and A. Farrel, "Generalized MPLS (GMPLS)
RSVP-TE Signaling Extensions in Support of Calls",
RFC 4974, August 2007.
[RFC6435] Boutros, S., Sivabalan, S., Aggarwal, R., Vigoureux, M.,
and X. Dai, "MPLS Transport Profile Lock Instruct and
Loopback Functions", RFC 6435, November 2011.
Authors' Addresses
Jie Dong
Huawei Technologies
Huawei Building, No.156 Beiqing Rd
Beijing 100095
China
Email: jie.dong@huawei.com
Mach Chen
Huawei Technologies
Huawei Building, No.156 Beiqing Rd
Beijing 100095
China
Email: mach.chen@huawei.com
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Zhenqiang Li
China Mobile
Unit2, Dacheng Plaza, No. 28 Xuanwumenxi Ave.
Beijing 100053
China
Email: lizhenqiang@chinamobile.com
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