MPLS Working Group Z. Ali
G. Swallow
Internet Draft Cisco Systems, Inc.
R. Aggarwal
Juniper Networks
Intended status: Standard Track March 05, 2009
Expires: September 04, 2009
Non PHP Behavior and out-of-band mapping for RSVP-TE LSPs
draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance
with the provisions of BCP 78 and BCP 79. This document may
contain material from IETF Documents or IETF Contributions
published or made publicly available before November 10,
2008. The person(s) controlling the copyright in some of
this material may not have granted the IETF Trust the right
to allow modifications of such material outside the IETF
Standards Process. Without obtaining an adequate license
from the person(s) controlling the copyright in such
materials, this document may not be modified outside the
IETF Standards Process, and derivative works of it may not
be created outside the IETF Standards Process, except to
format it for publication as an RFC or to translate it into
languages other than English.
Internet-Drafts are working documents of the Internet
Engineering Task Force (IETF), its areas, and its working
groups. Note that other groups may also distribute working
documents as Internet-Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be
accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on September 04, 2009.
Expires September 2009 [Page 1]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
Abstract
There are many deployment scenarios which require Egress LSR to
receive binding of the RSVP-TE LSP to an application, and payload
identification, using some "out-of-band" (OOB) mechanism. This
document proposes protocol mechanisms to address this
requirement. The procedures described in this document are
equally applicable for point-to-point (P2P) and point-to-
multipoint (P2MP) LSPs.
Conventions used in this document
In examples, "C:" and "S:" indicate lines sent by the client and
server respectively.
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 0.
Table of Contents
1. Introduction...............................................2
2. RSVP-TE signaling extensions...............................3
2.1. Signaling non-PHP behavior............................3
2.2. Signaling OOB Mapping Indication......................4
2.3. Relationship between OOB and non-PHP bits.............4
2.4. Egress Procedure for label binding....................4
3. Security Considerations....................................5
4. IANA Considerations........................................5
4.1. Attribute Flags for LSP_ATTRIBUTES object.............5
5. Acknowledgments............................................6
6. References.................................................6
6.1. Normative References..................................6
6.2. Informative References................................6
Author's Addresses............................................7
Intellectual Property Statement...............................7
Disclaimer of Validity........................................7
1. Introduction
When RSVP-TE is used for applications like MVPN [MVPN] and VPLS
[VPLS], an Egress LSR receives the binding of the RSVP-TE LSP to
an application, and payload identification, using an "out-of-
band" (OOB) mechanism (e.g., using BGP). In such cases, the
Egress LSR cannot make correct forwarding decision until such OOB
mapping information is received. Furthermore, in order to apply
the binding information, the Egress LSR needs to identify the
incoming LSP. Therefore, non Penultimate Hop Popping (non-PHP)
behavior is required at the Egress LSR to apply OOB mapping.
Expires September 2009 [Page 2]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
There are other applications that require non-PHP behavior. When
RSVP-TE P2MP LSPs are used to carry IP multicast traffic, non-PHP
behavior enables a leaf LSR to identify the P2MP TE LSP on which
traffic is received. Hence, the egress LSR can determine whether
traffic is received on the expected P2MP LSP and discard traffic
that is not received on the expected P2MP LSP. Non-PHP behavior
is also required to determine the context of upstream assigned
labels [UPSTREAM] when the context is a MPLS LSP.
This document defines two new bits in the Attributes Flags TLV of
the LSP_ATTRIBUTES object defined in [RFC5420]: one bit for
communication of non-PHP behavior, and one bit to indicate that
the binding of the LSP to an application and payload identifier
(payload-Id) needs to be learned via an out-of-band mapping
mechanism.
The procedures described in this document are equally applicable
for P2P and P2MP LSPs. Specification of the OOB communication
mechanism(s) is beyond the scope of the document.
2. RSVP-TE signaling extensions
This section describes the signaling extensions required to
address the above-mentioned requirements.
2.1. Signaling non-PHP behavior
In order to request non-PHP behavior for RSVP-TE LSP, this
document defines a new bit in the Attributes Flags TLV of the
LSP_ATTRIBUTES object defined in [RFC5420]:
Bit Number 6 (TBD): non-PHP behavior desired bit.
This bit SHOULD be set by Ingress node in the Attributes Flags
TLV of the LSP_ATTRIBUTES object in the Path message for the LSP
that desires Non-PHP behavior. This bit MUST NOT be modified by
any other nodes in the network. Nodes other than the Egress nodes
SHOULD ignore this bit.
If an egress node receiving the Path message, supports the
LSP_ATTRIBUTES object and the Attributes Flags TLV, and also
recognizes the "non-PHP behavior desired bit", it MUST allocate a
non-NULL local label. If the egress node supports the
LSP_ATTRIBUTES object but does not recognize the Attributes Flags
TLV, or supports the TLV as well but does not recognize this
particular bit, then it SHOULD simply ignore the above request.
Expires September 2009 [Page 3]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
An ingress node requesting non-PHP behavior MAY examine the label
value corresponding to the Egress node(s) in the RRO, and MAY
send a Path Tear to the Egress which assigns a Null label value.
2.2. Signaling OOB Mapping Indication
In order to indicate to the Egress LSR that binding of RSVP-TE
LSP to an application and payload identification is being
communicated by an OOB mechanism, this document defines a new bit
in the Attributes Flags TLV of the LSP_ATTRIBUTES object defined
in [RFC5420]:
Bit Number 7 (TBD): OOB mapping indication bit.
This bit SHOULD be set by Ingress node in the Attributes Flags
TLV of the LSP_ATTRIBUTES object in the Path message for the LSP
that desires OOB mapping. This bit MUST NOT be modified by any
other nodes in the network. Nodes other than the Egress nodes
SHOULD ignore this bit.
If an egress node receiving the Path message, supports the
LSP_ATTRIBUTES object and the Attributes Flags TLV, and also
recognizes the "OOB mapping indication bit", it MUST wait for the
OOB mapping before accepting traffic on the P2MP LSP. This
implies that the egress node MUST NOT setup forwarding state for
the P2MP LSP before it receives the OOB mapping, though it SHOULD
proceed with RSVP-TE signaling and send RESV messages as per
regular RSVP-TE procedures [RFC3209]. It MUST also ignore L3PID
in the Label Request Object [RFC3209]. If the egress node
supports the LSP_ATTRIBUTES object but does not recognize the
Attributes Flags TLV, or supports the TLV as well but does not
recognize this particular bit, then it SHOULD simply ignore the
above request.
2.3. Relationship between OOB and non-PHP bits
Non-PHP behavior desired and OOB mapping indication bit can
appear and be processed independently of each other. However, as
mentioned earlier, in the context of application discussed in
this draft, OOB mapping require non-PHP behavior. An Ingress node
requesting OOB mapping MAY also set non-PHP behavior desired bit
in the LSP_ATTRIBUTES object in the Path message.
2.4. Egress Procedure for label binding
RSVP-TE signaling completion and the OOB mapping information
reception happen asynchronously at the Egress. As mentioned in
Expires September 2009 [Page 4]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
Section 2, Egress waits for the OOB mapping before accepting
traffic on the P2MP LSP.
In order to avoid unnecessary use of the resources and possible
block-holing of traffic, if the OOB mapping information is not
received within a reasonable time, Egress MAY trigger a Path
Error message with the error code/sub-code "Notify Error/ no OOB
mapping received" for all affected LSPs. If available, and where
notify requests were included when the LSPs were initially setup,
Notify message (as defined in [RFC3473]) MAY also be used for
delivery of this information to the Ingress node. Egress node may
implement a cleanup timer for this purpose. The time-out value is
a local decision at the Egress, with recommended default value is
to be added later.
3. Security Considerations
This document does not introduce any new security issues above
those identified in [RFC3209], [RFC5420] and [RSVP-TE-P2MP].
4. IANA Considerations
4.1. Attribute Flags for LSP_ATTRIBUTES object
The following new bit is being defined for the Attributes Flags
TLV in the LSP_ATTRIBUTES object. The numeric value is to be
assigned by IANA.
o Non-PHP behavior desired bit - Bit Number 6 (Suggested value).
o OOB mapping indication bit - Bit Number 7 (Suggested value).
These bits are only to be used in the Attributes Flags TLV on a
Path message.
The following new error sub-code for Error Code = 25 "Notify
Error" (see [RFC3209]) is needed. The numeric value for this sub-
code is to be assigned by IANA.
o No OOB mapping received.
Expires September 2009 [Page 5]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
5. Acknowledgments
The authors would like to thank Yakov Rekhter for his suggestions
on the draft.
6. References
6.1. Normative References
[RFC5420] A. Farrel, D. Papadimitriou, J. P. Vasseur and A.
Ayyangar, "Encoding of Attributes for Multiprotocol
Label Switching (MPLS) Label Switched Path (LSP)
Establishment Using RSVP-TE", RFC 5420.
[RFC3209] D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[RSVP-TE-P2MP] R. Aggarwal, D. Papadimitriou, S. Yasukawa, et al,
"Extensions to RSVP-TE for Point-to-Multipoint TE
LSPs", RFC4875.
[RFC3473] L. Berger, Editor, "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC
3473, January 2003.
6.2. Informative References
[MVPN] E. Rosen, R. Aggarwal et al, "Multicast in MPLS/BGP IP
VPNs", draft-ietf-l3vpn-2547bis-mcast-07.txt.
[VPLS] R. Aggarwal, et al, "Propagation of VPLS IP Multicast
Group Membership Information", draft-raggarwa-l2vpn-
vpls-mcast-ctrl-00.txt, work in progress.
[UPSTREAM] TBA.
Expires September 2009 [Page 6]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
Author's Addresses
Zafar Ali
Cisco Systems, Inc.
Email: zali@cisco.com
George Swallow
Cisco Systems, Inc.
Email: swallow@cisco.com
Rahul Aggarwal
Juniper Networks
Email: rahul@juniper.net
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as
the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's
Legal Provisions Relating to IETF Documents in effect on the
date of publication of this document
(http://trustee.ietf.org/license-info). Please review these
documents carefully, as they describe your rights and
restrictions with respect to this document.
Legal
This documents and the information contained therein are provided
on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE
ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
Expires September 2009 [Page 7]
Internet-Draft draft-ietf-mpls-rsvp-te-no-php-oob-mapping-02.txt
Expires September 2009 [Page 8]