MPLS Working Group Zafar Ali Rakesh Gandhi Tarek Saad Internet Draft Cisco Systems, Inc. Intended status: Standard Track February 10, 2012 Expires: August 9, 2012 Signaling RSVP-TE P2MP LSPs in an Inter-domain Environment draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt 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 working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/. 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 August 9, 2012. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Expires August 2012 [Page 1] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt 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. Abstract Point-to-MultiPoint (P2MP) Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering Label Switched Paths (TE LSPs) may be established using signaling techniques described in [RFC4875]. However, [RFC4875] does not address many issues that come when a P2MP-TE LSP is signaled in inter-domain networks. Specifically, one of the issues in inter- domain networks is how to allow computation of a loosely routed P2MP-TE LSP such that it is re-merge free. Another issue is reoptimization of a P2MP-TE tree vs. reoptimization of an individual destination sub-LSP, as loosely routing domain border node is not aware of the reoptimization scope. This document provides a framework and required protocol extensions needed for establishing, controlling and reoptimizing P2MP MPLS and GMPLS TE LSPs in inter-domain networks. This document borrows inter-domain TE terminology from [RFC 4726], e.g., for the purposes of this document, a domain is considered to be any collection of network elements within a common sphere of address management or path computational responsibility. Examples of such domains include Interior Gateway Protocol (IGP) areas and Autonomous Systems (ASes). Conventions used in this document 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]. Expires January 2012 [Page 2] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt Table of Contents Copyright Notice..............................................1 1. Introduction...............................................3 2. Framework..................................................6 2.1. Signaling Options.....................................6 2.2. Path Computation Techniques...........................6 3. Control Plane Solution.....................................6 3.1. Single Border Node....................................6 3.2. Crankback and Path Error Signaling Procedure..........7 4. Data Plane Solution........................................8 4.1. P2MP-TE Re-merge Recording Request Flag...............8 4.2. P2MP-TE Re-merge Present Flag.........................9 4.3. Signaling Procedure...................................9 5. Reoptimization Signaling Procedure........................11 5.1. Caching of Path Query Result.........................12 6. Security Considerations...................................12 7. IANA Considerations.......................................13 8. Acknowledgments...........................................14 9. References................................................14 9.1. Normative References.................................14 9.2. Informative References...............................15 Author's Addresses...........................................16 1. Introduction [RFC4875] describes how to set up point-to-multipoint (P2MP) Traffic Engineering Label Switched Paths (TE LSPs) for use in MultiProtocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. As with all other RSVP controlled LSPs, P2MP LSP state is managed using RSVP messages. While the use of RSVP messages is mostly similar to their P2P counterpart, P2MP LSP state differs from P2P LSP in a number of ways. In particular, the P2MP LSP must also handle the "re-merge" problem described in [RFC4875] section 18. The term "re-merge" refers to the situation when two S2L sub-LSPs branch at some point in the P2MP tree, and then intersect again at another node further down the tree. This may occur due to discrepancies in the routing algorithms used by different nodes, errors in path calculation or manual configuration, or network topology changes during the establishment of the P2MP LSP. Such Expires January 2012 [Page 3] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt re-merges are inefficient due to the unnecessary duplication of data and using the additional bandwidth resources in the network. Consequently one of the requirements for signaling P2MP LSPs is to choose a P2MP path that is re-merge free. In some deployments, it may also be required to signal P2MP LSPs that are both re- merge and crossover free [RFC4875]. This requirement becomes more acute to address when P2MP LSP spans multiple domains. For the purposes of this document, a domain is considered to be any collection of network elements within a common sphere of address management or path computational responsibility. Examples of such domains include Interior Gateway Protocol (IGP) areas and Autonomous Systems (ASes). This is because in an inter-domain environment, the ingress node may not have topological visibility into other domains to be able to compute and signal a re-merge free P2MP LSP. In that case, the border node of a traversed domain is given loose next hops for one or more destinations in a P2MP LSP. The border node computes paths in its domain by individually expanding the loose next hops for the destinations belonging to the same P2MP LSP as they get signaled or grafted. One way for the border node to compute lower cost P2MP re-merge free paths is by favoring paths for newly grafted destination that branch off of the existing the P2MP LSP tree, as opposed to computing independent shortest path to loose next-hop. Note that computed P2MP tree by the border node in this case is subject to the order of computation of destination sub-paths and may not result in the optimal or minimal cost tree set. When processing a path message, the border node may not have knowledge of all of the destinations of the P2MP LSP, for example in the case when not all S2L sub- LSPs pass through this border node. In that case, existing protocol mechanisms do not provide sufficient information for it to be able to expand the loose hop(s) in such a way that the overall P2MP LSP path is guaranteed to be re-merge free. RFC 4875 specifies two approaches to handle re-merge conditions. In the first method that is based on control plane handling, the re-merge node initiates the removal of the re-merge branch(es) by sending a Path Error message. In the second method that is based on data plane handling, the node detecting the re-merge case, i.e., the re-merge node, allows the re-merge to persist, but data from all but one incoming interface is dropped at the re-merge node. This ensures that duplicate data is not sent on any outgoing interface. Expires January 2012 [Page 4] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt This document proposes RSVP-TE signaling procedures for P2MP LSP to handle re-merge for both using control plane approach and data plane approach. Control plane solution is using crankback signaling in RSVP. [RFC5151] describes mechanisms for applying crankback to inter- domain P2P LSPs, but does not cover P2MP LSPs. Also, crankback mechanisms for P2MP LSPs are not addressed by [RFC4875]. This document describes how crankback signaling extensions for MPLS and GMPLS RSVP-TE defined in [RFC4920] can be used for setting up P2MP TE LSPs to resolve re-merges. Date plane solution described in [RFC4875] is extended by adding a new flag in RRO Attributes Sub-object in RSVP. The proposed solution makes use of RRO Attributes Sub-object as defined in [RFC5420] for this purpose. This document describes how new RRO Attributes Flag can be used to handle P2MP re-merge conditions efficiently. RFC 4736 defines procedures and signaling extensions for reoptimizing an inter-domain LSP. Specifically a head-end node sends a "path re-evaluation request" to a border node by setting a flag (0x20) in SESSION_ATTRIBUTES object in a path message. A border node sends a path error code 25 (notify) with sub-code 6 to indicate, "preferable path exists" to the head-end node. This path error can be sent by the border node unsolicited or upon receiving a "path re-evaluation request". The head-end node upon receiving this path error may initiate reoptimization of the LSP. For P2MP LSP, a head-end node may reoptimize the whole P2MP LSP by resignaling all destinations, or may reoptimize one or more destination(s) in the P2MP LSP. For P2MP LSP, a border node may have loosely routed whole or part of the P2MP LSP by expanding loose hop EROs in path messages of the destinations. Currently a border node does not know with the signaling procedures defined in [RFC4736] if a head-end is requesting a reoptimization for one or more destination(s), or for the whole P2MP tree. Signaling extensions and procedures are defined in this document to support the reoptimization of the whole inter-domain P2MP LSP tree, or one or more destination(s) of the P2MP LSP. The solutions presented in this document do not guarantee optimization of the overall P2MP tree across all domains. PCE can be used, instead, to address optimization of the overall P2MP tree. Expires January 2012 [Page 5] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt 2. Framework 2.1. Signaling Options The four signaling options defined for P2P inter-domain LSPs in [RFC4726] are also applicable to P2MP LSPs. . LSP nesting, using hierarchical LSPs [RFC4206]. . A single contiguous LSP, using the same SESSION and LSP ID along its whole path. . LSP stitching [RFC5150]. . A combination of the above. In the case of LSP nesting using hierarchical LSPs, the tunneled LSP MUST use upstream-assigned labels to ensure that the same label is used at every leaf of the H-LSP ([RFC5331], [I-D. ietf- mpls-rsvp-upstream]). The H-LSP SHOULD request non-PHP behavior and out-of-band mapping as defined in [I-D. ietf-mpls-rsvp-te-no- php-oob-mapping]. 2.2. Path Computation Techniques This document focuses on the case where the ingress node does not have full visibility of the topology of all domains, and is therefore not able to compute the complete P2MP tree. Rather, it has to include loose hops to traverse domains for which it does not have full visibility, and the border node(s) on entry to each domain are responsible for expanding those loose hops. 3. Control Plane Solution It is RECOMMENDED that boundary re-routing or segment-based re- routing is requested for P2MP LSPs traversing multiple domains. This is because border nodes that are expanding loose hops are typically best placed to correct any re-merge errors that occur within their domain, not the ingress node. 3.1. Single Border Node The ingress node is RECOMMENDED to select the same border node as an ERO loose hop for all sibling S2L sub-LSPs that transit a Expires January 2012 [Page 6] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt given domain. This reduces the chances of the sibling S2L sub- LSPs in remerging states, because a single border node has the necessary state to ensure that the path that they take through the domain is re-merge free. 3.2. Crankback and Path Error Signaling Procedure As mentioned in [RFC4875], in order to avoid duplicate traffic, the re-merge node MAY initiate the removal of the re-merge S2L sub-LSPs by sending a Path Error message to the ingress node of the S2L sub-LSP. Crankback procedures for rerouting around failures for P2P RSVP- TE LSPs are defined in [RFC4920]. These techniques can also be applied to P2MP LSPs to handle re-merge conditions, as described in this section. If a node on the path of the P2MP LSP is unable to find a route that can supply the required resources or that is re-merge free, it SHOULD generate a Path Error message for the subset of the S2L sub-LSPs which it is not able to route. For this purpose the node SHOULD try to find a minimum subset of S2L sub-LSPs for which the Path Error needs to be generated. This rule applies equally to the case where multiple S2L sub-LSPs are signaled using one Path message, as to the case where a single S2L sub-LSP is signaled in each Path message. RSVP-TE Notify messages do not include S2L_SUB_LSP objects and cannot be used to send errors for a subset of the S2L sub-LSPs in a Path message. For that reason, the node SHOULD use a Path Error message rather than a Notify message to communicate the error. In the case of a re-merge error, the node SHOULD use the error code "Routing Problem" and the error value "ERO resulted in re-merge" as specified in [RFC4875]. A border node receiving a Path Error message for a set of S2L sub-LSPs MAY hold the message and attempt to signal an alternate path that can avoid re-merge through its domain for those S2L sub-LSPs that pass through it. However, in the case of a re-merge error for which some of the re-merging S2L sub-LSPs do not pass through the border node, it SHOULD propagate the Path Error upstream to the ingress node. If the subsequent attempt by the border node is successful, the border node discards the held Path Error and follows the crank back roles of [RFC4920] and [RFC5151]. If all subsequent attempts by the border node are unsuccessful, the border node MUST send the held Path Error upstream to the ingress node. Expires January 2012 [Page 7] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt If the ingress node receives a Path Error message with error code "Routing Problem" and error value "ERO resulted in re-merge", then it SHOULD attempt to signal an alternate path through a different domain or through a different border node for the affected S2L sub-LSPs. However, it may be that the ingress node or a border node does not have sufficient topology information to compute an Explicit Route that is guaranteed to avoid the re-merge link or node. In this case, Route Exclusions [RFC4874] may be particularly helpful. To achieve this, [RFC4874] allows the re-merge information to be presented as route exclusions to force avoidance of the re-merge link or node. As discussed in [RFC4090] section 3.3, border node MAY keep the history of Path Errors. In case of P2MP LSPs, ingress node and border nodes may keep re-merge Path Errors in history table until S2L sub-LSPs have been successfully established or until local timer expires. 4. Data Plane Solution As mentioned in [RFC4875], node may accept the remerging S2Ls but only send the data from one of these interfaces to its outgoing interfaces. That is, the node MUST drop data from all but one incoming interface. This ensures that duplicate data is not sent on any outgoing interface. It is desirable to avoid the persistent re-merge condition associated with data plane based solution in the network in order to optimize bandwidth resources in the network. RSVP-TE signaling extensions are defined in the following to request P2MP-TE Re-merge Recording and indicate P2MP-TE Re-merge Presence. 4.1. P2MP-TE Re-merge Recording Request Flag In order to indicate nodes that P2MP-TE Re-merge Recording is desired, a new flag in the Attribute Flags TLV of the LSP_ATTRIBUTES object defined in [RFC5420] is defined as follows: Bit Number (to be assigned by IANA): P2MP-TE Re-merge Recording Request flag Expires January 2012 [Page 8] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt The P2MP-TE Re-merge Recording Request flag is meaningful on a Path message and can be inserted by the ingress node or a border node. If the P2MP-TE Re-merge Recording Flag is set to 1, it means that "P2MP-TE Re-merge Presence" defined in the next section should be used to indicate to the ingress and border nodes along the setup of the LSP that a re-merge is present but accepted and that incoming traffic is being dropped for the given S2L. The rules of the processing of the Attribute Flags TLV of the LSP_ATTRIBUTES object follow [RFC5420]. 4.2. P2MP-TE Re-merge Present Flag The P2MP-TE Re-merge Present Flag is the counter part of the P2MP-TE Re-merge Recording Request flag defined above. Specifically, RSVP signaling extension is defined to indicate to the upstream node of the re-merge condition and that incoming traffic is being dropped for the given S2L. When a node decides to accept re-merge and drop traffic from an incoming interface for an S2L due to the re-merge condition, and understands the "P2MP-TE Re-merge Recording Request" in the Attribute Flags TLV of the LSP_ATTRIBUTES object of the Path message, the node SHOULD set the newly defined "P2MP-TE Re-merge Present" flag in the RRO Attributes sub-object defined in [RFC 5420] in RRO. The following new flag for RRO Attributes Sub-object is defined as follows: Bit Number (same as bit number assigned for P2MP-TE Re- merge Recording Request flag): P2MP-TE Re-merge Present flag The presence of P2MP-TE Re-merge Present flag indicates that the S2L is causing a re-merge. The re-merge has been accepted but the incoming traffic on this S2L is dropped by the reporting node. 4.3. Signaling Procedure When a node receives an S2L sub-LSP Path message with LSP Attributes sub-object that has "P2MP-TE Re-merge Recording Request" Flag set, and the node does not support data plane based re-merge handling, and the S2L is causing a re-merge, the node Expires January 2012 [Page 9] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt SHOULD reject the S2L sub-LSP path message and send the Path Error with the error code "Routing Problem" and the error value "ERO resulted in re-merge" as specified in [RFC4875]. When a path message is received at a transit node and "P2MP-TE Re-merge Recording Request" Flag is set in the LSP Attributes sub-object, the node MAY decide to accept the re-merge S2L sub- LSP. In this case, before the Resv message is sent to the upstream node, the node adds the RRO Attributes sub-object to the RRO and sets the "P2MP-TE Re-merge Recording Request" Flag. When a transit node receives a reservation message for an S2L that is causing a re-merge, the node SHOULD set the "P2MP-TE Re- merge Present" flag in the RRO Attributes sub-object in the reservation message if it decides to drop the incoming traffic of this S2L. "P2MP-TE Re-merge Present" flag in RRO Attribute sub- object is not set for the S2Ls if the node has selected the incoming interface of the S2Ls to forward the traffic. An ingress node MAY immediately start sending traffic on all S2Ls in up state even when re-merges are present on some S2Ls of the P2MP LSP. Proposed signaling extensions allow an ingress node and a border node to have a complete view of the re-merges on entire S2L path and on all S2Ls of the P2MP tree and can take appropriate actions to resolve re-merges and optimize network bandwidth resources. The proposed signaling extensions are equally applicable to single domain scenarios. A node may need to select a different incoming interface to forward traffic in future. In that case, a reservation change message is sent upstream indicating the change by marking or clearing the "P2MP-TE Re-merge Present" flag appropriately for all effected S2Ls. The re-merge node SHOULD NOT dynamically change incoming interface to forward traffic to avoid unnecessary race conditions. A border node due to local policy MAY remove the record route object from the reservation message of the S2L sub-LSP and propagate reservation message towards the ingress node. When such a policy is provisioned, the border node may attempt to correct the re-merge condition in its domain. If the border node is not able to resolve the re-merge condition, the border node SHOULD Expires January 2012 [Page 10] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt send the Path Error with the error code "Routing Problem" and the error value "ERO resulted in re-merge" as specified in [RFC4875]. 5. Reoptimization Signaling Procedure Using signaling procedure defined in [RFC4736], a head-end node MAY initiate "path re-evaluation request" query to reoptimize a destination in a P2MP LSP. Note that this message SHOULD be used to reoptimize a single or a sub-set of the destinations in a P2MP LSP. Head-end node sends this query in the path message for each destination it is reoptimizing. When a path message for a destination in a P2MP LSP with "path re-evaluation request" flag [RFC4736] is received at the border node, it SHOULD recompute the ERO to see if a preferred path exists for that destination. A border node MAY send path error 25 with "preferred path exists" sub-code to indicate that a preferred path exists for the requested destination AND border node is capable of per destination sub-LSP reoptimization. When a border node is not capable of per destination sub-LSP reoptimization, it MAY terminate the path query OR respond with the new "Preferred P2MP-TE Tree Exists" path error (defined below) by checking for a preferred P2MP tree. It is often desired to reoptimize the whole P2MP LSP tree. In order to query border nodes to check if a preferred P2MP tree exists, head-end node MAY send path message with newly defined flag in Attributes Flags TLV of the LSP_ATTRIBUTES object [RFC5420] as follows: Bit Number (to be assigned by IANA): P2MP-TE Tree Re- evaluation Request flag The P2MP-TE tree re-evaluation request flag is meaningful in a Path message and can be inserted by the head-end node. A head-end node MAY send this message for all destinations in a P2MP LSP or a sub-set of the destinations (e.g. those traversing a specific border node). A border node receiving the new "P2MP-TE tree re-evaluation request" SHOULD check for a preferred P2MP LSP for the destinations it is loosely routing by ERO expansions and if a preferred P2MP-TE tree is found, it SHOULD reply with "Preferred P2MP-TE tree exists" path error and terminate the path query. If no preferred tree is found it SHOULD propagate the query downstream. Expires January 2012 [Page 11] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt Following new sub-code for path error code 25 is defined: Sub-code (to be assigned by IANA): Preferred P2MP-TE Tree Exists flag When a preferred P2MP tree is found, the border node MAY send a newly defined sub-code "Preferred P2MP-TE tree exists" with path error code 25 to indicate the head-end node to reoptimize the whole P2MP LSP. A border node may send the path error with "Preferred P2MP-TE tree exists" message unsolicited or in a response to "path re- evaluation query" for one more destination(s) sub-LSP(s) or in a response to the newly defined "P2MP-TE tree re-evaluation request" query. If a head-end node initiated a "path re-evaluation request" query for a single destination sub-LSP reoptimization and receives "Preferred P2MP-TE Tree Exists" path error, head-end MAY cancel the destination sub-LSP reoptimization and initiate the whole P2MP LSP tree reoptimization. This may happen in cases when a border node is not capable of per destination sub-LSP reoptimization. 5.1. Caching of Path Query Result Once a mid-point border node has determined that a preferable P2MP tree exists, this decision MAY be cached on the node for a limited amount of time to avoid having to recompute a new tree when subsequent path queries are received for the same P2MP LSP. A default value of 30 seconds for the caching timer is suggested. In addition, the new optimal P2MP tree ERO information MAY be cached such that when the newly reoptimized P2MP LSP gets signaled, the border node MAY not need to perform the loose hop ERO expansions again, but rather pick the path from the cached P2MP tree. This mode is optional. 6. Security Considerations This document does not introduce any additional security issues above those identified in [RFC3209], [RFC4875], [RFC5151], [RFC4920] and [RFC5920]. Expires January 2012 [Page 12] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt 7. IANA Considerations The following new flag is defined for the Attributes Flags TLV in the LSP_ATTRIBUTES object. The numeric values are to be assigned by IANA. o P2MP-TE Re-merge Recording Request Flag: - Bit Number: To be assigned by IANA. - Attribute flag carried in Path message: Yes - Attribute flag carried in Resv message: No The following new flag is defined for the RRO Attributes sub- object in the RECORD_ROUTE object. The numeric values are to be assigned by IANA. o P2MP-TE Re-merge Recording Present Flag: - Bit Number: To be assigned by IANA. - Attribute flag carried in Path message: No - Attribute flag carried in RRO Attributes sub-object in RRO of the Resv message: Yes The following new flag is defined for the Attributes Flags TLV in the LSP_ATTRIBUTES object. The numeric value is to be assigned by IANA. o P2MP-TE Tree Re-evaluation Request Flag: - Bit Number: To be assigned by IANA. - Attribute flag carried in Path message: Yes - Attribute flag carried in Resv message: No Expires January 2012 [Page 13] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt As defined in [RFC3209], the Error Code 25 in the ERROR SPEC object corresponds to a Notify Error. This document adds a new sub-code as follows. The numeric value is to be assigned by IANA. o Sub-code for Notify Path Error code 25: - Sub-code - To be assigned by IANA: Preferred P2MP-TE Tree Exists. 8. Acknowledgments The authors would like to thank N. Neate for his contributions on the draft. 9. References 9.1. Normative References [RFC4875] Aggarwal, R., Papadimitriou, D., and S. Yasukawa, "Extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE Label Switched Paths (LSPs)", RFC 4875, May 2007. [RFC5151] Farrel, A., Ayyangar, A., and JP. Vasseur, "Inter- Domain MPLS and GMPLS Traffic Engineering -- Resource Reservation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 5151, February 2008. [RFC4920] Farrel, A., Satyanarayana, A., Iwata, A., Fujita, N., and G. Ash, "Crankback Signaling Extensions for MPLS and GMPLS RSVP-TE", RFC 4920, July 2007. [RFC5920] L. Fang, Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010. [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. [RFC4736] Vasseur, JP, Ikejiri, Y. and Zhang, R. "Reoptimization of Multiprotocol Label Switching (MPLS) Traffic Engineering (TE) Loosely Routed Label Switched Path (LSP)", RFC 4736, November 2006 Expires January 2012 [Page 14] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt 9.2. Informative References [RFC4726] Farrel, A., Vasseur, J., and A. Ayyangar, "A Framework for Inter-Domain Multiprotocol Label Switching Traffic Engineering", RFC 4726, November 2006. [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. [RFC5150] Ayyangar, A., Kompella, K., Vasseur, JP., and A. Farrel, "Label Switched Path Stitching with Generalized Multiprotocol Label Switching Traffic Engineering (GMPLS TE)", RFC 5150, February 2008. [RFC5331] Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream Label Assignment and Context-Specific Label Space", RFC 5331, August 2008. [I-D.ietf-mpls-rsvp-upstream] Aggarwal, R. and J. Roux, "MPLS Upstream Label Assignment for RSVP-TE", draft-ietf- mpls-rsvp-upstream-05 (work in progress), March 2010. [I-D.ietf-mpls-rsvp-te-no-php-oob-mapping] Ali, Z. and G. Swallow, "Non PHP Behavior and out-of-band mapping for RSVP-TE LSPs", draft-ietf-mpls-rsvp-te-no-php-oob- mapping-04 (work in progress), March 2010. Expires January 2012 [Page 15] Internet-Draft draft-ali-mpls-inter-domain-p2mp-rsvp-te-lsp-07.txt Author's Addresses Zafar Ali Cisco Systems, Inc. 2000 Innovation Drive Kanata, Ontario, K2K 3E8 Canada Email: zali@cisco.com Rakesh Gandhi Cisco Systems, Inc. 2000 Innovation Drive Kanata, Ontario, K2K 3E8 Canada Email: rgandhi@cisco.com Tarek Saad Cisco Systems, Inc. 2000 Innovation Drive Kanata, Ontario, K2K 3E8 Canada Email: tsaad@cisco.com Expires January 2012 [Page 16]