Internet Engineering Task Force C. Jacquenet Internet-Draft France Telecom Orange Intended status: Informational Q. Zhao Expires: September 13, 2012 Huawei Technology March 12, 2012 Receiver Driven Multicast RSVP TE Requirements draft-jacquenet-mpls-rd-p2mp-te-requirements-01.txt Abstract This document presents a set of requirements for the establishment and maintenance of Receiver-Driven Point-to-Multipoint (P2MP) and Multipoint-to-Multipoint (MP2MP) Traffic-Engineered (TE) Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs). 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 September 13, 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 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. Jacquenet & Zhao Expires September 13, 2012 [Page 1] Internet-Draft RD mRSVP TE Requirements March 2012 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.3. What is not covered in this doc? . . . . . . . . . . . . . 4 2. Basic Requirements . . . . . . . . . . . . . . . . . . . . . . 5 3. Leaf Driven mRSVP-TE LSP Exampls . . . . . . . . . . . . . . . 8 4. Detailed Requirements . . . . . . . . . . . . . . . . . . . . 10 4.1. Leaf Driven mRSVP-TE LSP . . . . . . . . . . . . . . . . . 10 4.2. P2MP TE LSP Establishment, Teardown, and Modification Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . 10 4.3. Re-Optimization of Leaf Driven mRSVP-TE LSPs . . . . . . . 11 4.4. Support for LAN interfaces . . . . . . . . . . . . . . . . 11 4.5. P2MP/MP2MP MPLS Label . . . . . . . . . . . . . . . . . . 12 4.6. Advertisement of Leaf Driven mRSVP-TE Capability . . . . . 12 4.7. Scalability . . . . . . . . . . . . . . . . . . . . . . . 12 4.8. Variation of LSP Parameters . . . . . . . . . . . . . . . 14 5. In-Band Signalling . . . . . . . . . . . . . . . . . . . . . . 14 6. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 14 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 9. Security Considerations . . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 10.1. Normative References . . . . . . . . . . . . . . . . . . . 15 10.2. Informative References . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Jacquenet & Zhao Expires September 13, 2012 [Page 2] Internet-Draft RD mRSVP TE Requirements March 2012 1. Introduction For content delivery services that rely upon the IP multicast transmission scheme, the distribution trees are receiver-initiated. The delivery of such services over MPLS networking infrastructures may rely upon P2MP LSP tree structures that are currently source- initiated, with the root of the P2MP tree being at the LSR router directly connected to the sender ([RFC4875]. Multiparty multimedia applications are getting greater attention in the telecom world. Such applications are QoS-demanding and can therefore benefit from the activation of MPLS traffic engineering capabilities that lead to the dynamic computation and establishment of MPLS LSPs whose characteristics comply with application-specific QoS requirements. P2MP-RE-REQ[RFC4461] specifies the signalling requirements to setup multipoint LSPs from source to receiver. P2MP-TE [RFC4875] defines the procedure to setup multipoint LSPs from source to receiver. This document presents a set of requirements specific for the dynamic establishment and maintenance of receiver-driven P2MP-TE and MP2MP-TE LSPs. 1.1. Motivation IP multicast distribution trees are receiver-initiated and dynamic by nature. IP multicast-enabled applications are also bandwidth savvy, especially in the area of residential Live TV broadcasting services, where several hundreds of thousands of IPTV receivers need to be served with the appropriate level of quality. Current source-driven P2MP LSP establishment assumes a prior knowledge of receiver(s) location for the sake of the P2MP LSP tree structure's forwarding efficiency. But the receiver's location information is not available a priori for the root MPLS router to compute and establish the relevant P2MP tree structure. In addition, with the source-driven P2MP-TE solution, full mesh P2MP LSP tree structures need to be established to setup a MP2MP LSP, possibly raising scalability issues for the delivery of some multicast services, such as videoconferencing at large scale. From this perspective, it is believed that receiver-driven MPLS P2MP tree structures represent the best of breed that combines the benefits of IP multicast, receiver-driven dynamics with the benefits of MPLS-based, QoS-guaranteed LSP path computation. Thus, receiver-driven MPLS P2MP/MP2MP tree structure do not require that the root of the MPLS P2MP tree structure dynamically discovers Jacquenet & Zhao Expires September 13, 2012 [Page 3] Internet-Draft RD mRSVP TE Requirements March 2012 and maintains receiver information a priori. In addition, such a receiver-driven approach encourages computation schemes that can take into account the network access conditions of the receivers (bandwidth capabilities, IPTV customer profile, etc.) for the sake of customer's Quality of Experience (time to access an IPTV channel, time to zap fron one channel to another, etc.). 1.2. Terminology The following terms are used in this document:> o Sender: Sender refers to the source of the content/payload. As in [RFC2205]. o Receiver: Receiver refers to the Receiver of the content/payload. As in [RFC2205]. o Upstream: The direction of a flow from a content Receiver towards a content Sender. As defined in [RFC2205]. o Downstream: The direction of a flow from a content Sender towards a content Receiver. As defined in [RFC2205]. o Path-Sender: The sender of the RSVP_PATH message, with NO correlation to the directionality of the corresponding content flow. o Path-Receiver: The receiver of the RSVP_PATH message, with NO correlation to the directionality of the corresponding content flow. o Path-Initiator: The Path-Sender that originated the RSVP_PATH message. The Path-Initiator is a notion that differs from the Path-Sender because an intermediate node can be a Path-Sender, and therefore different from the node that created and initiated the RSVP_PATH message, which is precisely the Path- Initiator. o Path-Terminator: The Path-Receiver that does NOT propagate the Path message. This is a notion that differs from the Path- Receiver because an intermediate node can be a Path-Receiver. 1.3. What is not covered in this doc? This document does not specify any requirements for the following functions. Jacquenet & Zhao Expires September 13, 2012 [Page 4] Internet-Draft RD mRSVP TE Requirements March 2012 o Discovery of the root node for a given P2MP/MP2MP tree structure. o Algorithms for computing P2MP/MP2MP distribution trees. o Hierarchical P2MP/MP2MP LSPs. o OAM for P2MP/MP2MP LSPs. o Inter-area and inter-AS P2MP/MP2MP TE LSPs. o Applicability of P2MP/MP2MP MPLS TE LSPs to service scenarios. o Specific application requirements. o Routing protocols. o Construction of the traffic engineering database. o Distribution of the information used to construct the traffic engineering database. 2. Basic Requirements [RFC4461] specifies requirements for P2MP traffic engineering over MPLS. It describes sender-driven P2MP traffic engineering in detail. Those definitions and requirements are equally applicable to receiver-driven traffic engineering in a point-to-multipoint service environment and are therefore not repeated here. Following are key requirements that are specific to the receiver- driven paradigm: REQ1: The receiver-driven P2MP/MP2MP approach must be scalable, i.e., the dynamic computation and maintenance of P2MP/MP2MP tree structures must be adapted to typical live TV broadcasting services that connect several hundreds of thousands of receivers. REQ2: Leaves of receiver-driven P2MP/MP2MP tree structures must be aware of the corresponding P2MP/MP2MP LSP identifiers for tree computation and maintenance purposes. REQ3: The receiver-driven mechanism MUST allow the dynamic addition and removal of leaves to and from a P2MP/MP2MP tree structure, without any restriction (provided there is network connectivity) . It is RECOMMENDED that the corresponding operations be leaf-initiated. Jacquenet & Zhao Expires September 13, 2012 [Page 5] Internet-Draft RD mRSVP TE Requirements March 2012 REQ4: The dynamic addition and removal of leaves to and from a receiver-driven P2MP/MP2MP LSP MUST not impact the performances of the data forwarding (packet loss, replication, delay) towards other leaves. REQ5: The dynamic addition and removal of leaves to and from a receiver-driven P2MP/MP2MP LSP SHOULD NOT infer any additional processing than that on the path from the added/ removed Leaf LSR to the Branch LSR. REQ6: A Leaf router MUST initiate RSVP PATH message towards the root and also signal the type of the LSP. REQ7: The destination of a L2S (Leaf-to-Source) sub-path MUST be one of the ingress routers where multicast data sent by a source enter the P2MP/MP2MP LSP tree structure. REQ8: RSVP P2MP PATH messages MUST be forwarded along the path from a given leaf to the root of the P2MP tree structure. REQ9: RSVP P2MP RESV messages MUST be frowarded along the path from the root to the receiver if the leaf is the MPLS router that directly connects receivers to the corresponding receiver- driven P2MP tree structure . Otherwise, RSVP P2MP RESV messages will be forwarded from the PATH Terminator to the PATH Initiator. REQ10: A node receiving a RSVP RESV message SHOULD interpret it as a successful resource reservation from the upstream node for the establishment of the P2MP tree structure. REQ11: A node receiving a RSVP RESV message SHOULD interpret it as a successful resource reservation from the downstream node for the establishment of the MP2MP tree structure. REQ12: Label allocation on incoming interface MUST be done prior to sending RSVP PATH messages upstream for P2MP tree structures. REQ13: Label allocation on incoming interface MUST be done prior to sending RSVP RESV messages upstream for MP2MP tree structures. REQ14: For P2MP LSP tree structures, a node receiving a RSVP PATH message MUST first decide if this RSVP PATH message will make itself a branch LSR or not. In the case that it will become a transit LSR because of this PATH message, then it will allocate required resources on the interface through which the RSVP PATH message is received, before sending the RSVP Jacquenet & Zhao Expires September 13, 2012 [Page 6] Internet-Draft RD mRSVP TE Requirements March 2012 PATH message upstream. So that the upstream node can send traffic soon after successfully reserving resources on the downstream link, on which the RSVP PATH message SHOULD be received. In the case that the node is a branch or transit node already before it receives the PATH message, then it will allocate required resources (provided they are available) on the interface through which the RSVP PATH message is received, and then send the RESV message back to the node that sent the PATH message without sending the PATH message upstream. REQ15: For MP2MP LSP tree structures, a node will allocate required resources on the interface through which the RSVP PATH message is sent, before sending the RSVP PATH message upstream. A node receiving a RSVP PATH message MUST first decide if this RSVP PATH message will make itself a branch LSR or not. In the case that it will become a transit LSR because of this PATH message, and then allocate required resources (provided they are available) on the interface through which the RSVP PATH message was received and will allocate required resources on the interface through which the RSVP PATH message is sent, before sending it upstream. So that the downstream node can send traffic soon after successfully reserving resources on the upstream link, on which the RSVP PATH message SHOULD be sent. The upstream node can then send traffic soon after successfully reserving resources on the downstream link, on which the RSVP PATH message SHOULD be received. In the case that the node is a branch or transit node already before it receives the PATH message, then it will allocate required resources on the interface through which the RSVP PATH message is received, and send the RESV message to the node which sent the PATH message without sending the PATH message upstream. Jacquenet & Zhao Expires September 13, 2012 [Page 7] Internet-Draft RD mRSVP TE Requirements March 2012 3. Leaf Driven mRSVP-TE LSP Exampls Path Terminator/Ingress Router +---------+ | R1 | +-----+---+ _ \ \ /\ \ \ \ Path Message w/ Label OBJECT Resv \ \ \ (msg2) Message \ \ \ (msg3) \ \ \ _\/ \ \ +----------------+ Path Remerge | R3 | Creates Branch Point +----------------+ _ _ / / /\ \ \ /\ / / / \ \ \ Path Message (msg1) Resv Message / / / msg4 \ \ \ w/ Label OBJECT (msg6) / / / \ \ \ / / /Path Msg \ \ \ / / / msg5 \ \ \ \/_ / / w/Label OBJ _\/ \ \ +----------+ +---+-----+ | R4 | | R5 | +----------+ +---------+ Path Initiator Path Initiator Originator ID = R4 Originator ID = R5 L2S Destination = R1 L2S Destination = R1 Session = S Session = S Figure 1: P2MP Example Figure 1 shows that R5 is added as the first leaf of the RD P2MP TE LSP, the message flow goes from R5->msg1->R3->msg2->R1->msg3->R3->msg4->R5. When the leaf R4 is added, the message flow goes from R4->msg5->R3->msg6->R4. In this case, when R3 receives msg5, R3 finds out that the RD P2MP LSP has already been set up for R5: therefore, R3 finds itself a branch node for leaf R4 and R5, so it will terminate the PATH message and build the corresponding RESV message and send it back to R4. The association of the LSP initiated by R4 to the existing RD P2MP LSP is determined based on the processing of the session object from the mRSVP-TE message. This session object is further documented in Section 2 of this draft. Jacquenet & Zhao Expires September 13, 2012 [Page 8] Internet-Draft RD mRSVP TE Requirements March 2012 Path Terminator/Ingress Router +---------+ | R1 | +-----+---+ _ \ \ /\ \ \ \ Path-mp2mp Message w/ Label OBJECT Resv \ \ \ (msg2) Message \ \ \ (msg3) \ \ \ w/ Label OBJECT _\/ \ \ +----------------+ Path-mp2mp | R3 | (Branch Point) +----------------+ _ _ / / /\ \ \ /\ / / / \ \ \ Path-mp2mp Message (msg1) Resv Message / / / msg4 \ \ \ (msg1) (msg6) / / / \ \ \ w/ Label OBJECT w/ Label OBJECT/ / /Path-mp2mp \ \ \ / / / Message \ \ \ / / / (msg5) \ \ \ \/_ / / w/ Label OBJ _\/ \ \ +----------+ +---+-----+ | R4 | | R5 | +----------+ +---------+ Path-mp2mp Initiator Path-mp2mp Initiator Originator ID = R4 Originator ID = R5 L2S Destination = R1 L2S Destination = R1 Session = S Session = S Figure 2: MP2MP Example Figure 2 shows that R5 is added as the first leaf (as both a sender and a receiver) of the RD MP2MP TE LSP, the message flow goes from R5->msg1->R3->msg2->R1->msg3->R3->msg4->R5. When the leaf R4 (both receiver and sender)is added, the message flow goes from R4->msg5->R3->msg6. In this case, when R3 receives msg5, R3 finds out that the RD MP2MP LSP has already been set up for R5, and R3 will become the branch LSR for the leaf R4 and R5, so it will terminate the PATH message, build a RESV message and send the RESV message back to R4. The association of the LSP initiated by R4 to the existing MP2MP LSP is determined based on the processing of the session object from the mRSVP-TE message. This session object is further documented in Section 2 of this draft. Jacquenet & Zhao Expires September 13, 2012 [Page 9] Internet-Draft RD mRSVP TE Requirements March 2012 4. Detailed Requirements 4.1. Leaf Driven mRSVP-TE LSP The Receiver-Driven RSVP-TE extensions MUST be applicable to the signaling of P2MP LSPs for different switching types. For example, it MUST be possible to signal a P2MP/MP2MP TE LSP in any switching medium, whether it is packet or non-packet based (including frame, cell, TDM, lambda, etc.). As with P2P MPLS technology [RFC3031], a given traffic is associated with a FEC in this extension. All packets that belong to a particular FEC and that travel from a particular node MUST follow the same Receiver- Driven P2MP/MP2MP tree structure. In order to scale to a large number of branches, P2MP/MP2MP TE LSPs SHOULD be identified by a unique identifier (the P2MP/MP2MP ID) that is constant for the whole LSP regardless of the number of branches and/or leaves. 4.2. P2MP TE LSP Establishment, Teardown, and Modification Mechanisms The Receiver-Driven P2MP LSP approach MUST support the dynamic establishment, maintenance, and teardown of Receiver-Driven P2MP/ MP2MP LSPs in a manner that the scalability is not affected by the number of leaves, and it is scalable in a linear way to the number of branches for a node. This MUST imply the ability to compute to compute multiple P2MP tree structures at once, and to compute P2MP/ MP2MP LSP tree structures are that composed of many leaves, i.e., within the magnitude of typical Live TV broadcasting designs that accommodate several hundreds of thousands of receivers. In addition to signaling capabilities for P2MP/MP2MP LSP establishment and teardown, the solution SHOULD support capabilities that allow the dynamic modification of part of a given P2MP/MP2MP tree structure without altering the whole structure: For the purpose of adding sub-P2MP TE LSPs to an existing P2MP/MP2MP TE LSP, the extensions SHOULD support a grafting mechanism. For the purpose of deleting a sub-P2MP TE LSP from an existing P2MP/MP2MP TE LSP, the extensions SHOULD support a pruning mechanism. It is RECOMMENDED that these grafting and pruning operations cause no additional processing in nodes that are not along the path from the grafting or pruning node to the upstream branch node. Moreover, both grafting and pruning operations MUST NOT disrupt the forwarding of traffic along the P2MP/MP2MP tree at any given time. Jacquenet & Zhao Expires September 13, 2012 [Page 10] Internet-Draft RD mRSVP TE Requirements March 2012 There is no assumption that the explicitly routed P2MP/MP2MP LSP remains on an optimal path after several grafts and prunes have occurred. In this context, scalability considerations refer to the signaling process for the P2MP/MP2MP TE LSP . The TE nature of the LSP allows that re- optimization may take place from time to time to restore the optimality of the LSP. 4.3. Re-Optimization of Leaf Driven mRSVP-TE LSPs The detection of a more optimal path (for example, one with a lower overall cost) is an example of a situation where re-routing of the Receiver-Driven P2MP/MP2MP LSP may be required. While re-routing is in progress, an important requirement is to avoid double bandwidth reservation (over the common parts between the old and new LSP) through the use of resource sharing. A Make-before-break design MUST be supported for Receiver-Driven P2MP/MP2MP LSPs to ensure that there is minimal traffic disruption during the re-routing operations. Make-before-break that only applies to a sub-P2MP tree without impacting the data on all the other parts of the P2MP tree MUST be supported. The solution SHOULD allow for make-before-break re-optimization of any subdivision of the P2MP LSP. It SHOULD do so by not having any signaling impact on the rest of the P2MP LSP, and without affecting the ability of the management plane to manage the LSP. The solution SHOULD also provide the ability for any downstream LSR to have control over the re-optimization process . Where sub-LSP re-optimization is allowed by the ingress LSR, such re- optimization MAY be initiated by a downstream LSR that is the root of the sub-LSP to be re-optimized. Sub-LSP re-optimization initiated by a downstream LSR MUST be carried out with the same regard to minimizing the impact on active traffic as mentioned above for other re-optimization purposes. 4.4. Support for LAN interfaces Receiver-Driven P2MP/MP2MP LSPs may be used to traverse network segments that are provided by multi-access media such as Ethernet. In these contexts, it is also possible that the entry point to the network segment is a branch LSR of the Receiver-Driven P2MP/MP2MP LSP. To avoid all replicated data are sent through the same port and Jacquenet & Zhao Expires September 13, 2012 [Page 11] Internet-Draft RD mRSVP TE Requirements March 2012 carried on the same segment, the solution SHOULD provide a mechanism for a branch LSR to send a single copy of the data onto a multi- access network to reach multiple (adjacent) downstream nodes. The Receiver-Driven P2MP/MP2MP computation mechanism SHOULD provide a means for a Branch LSR to send a single copy of the data onto an Ethernet LAN interface to reach multiple adjacent downstream nodes. This requires that the same label be negotiated with all downstream LSRs for the P2MP/MP2MP LSP. When there are several candidate upstream LSRs on a LAN interface, the RD P2MP TE mechanism SHOULD provide a means for all downstream LSRs of a given P2MP LSP to select the same upstream LSR, so as to avoid traffic replication. In addition, the RD P2MP TE mechanism SHOULD allow for an efficient balancing of a set of P2MP LSPs among a set of candidate upstream LSRs on a LAN interface. 4.5. P2MP/MP2MP MPLS Label A solution for the dynamic establishment and maintenance of Receiver- Driven P2MP LSPs MUST allow the continued use of existing techniques to establish P2P and legacy P2MP LSPs (TE and otherwise) within the same network, and MUST allow the coexistence of Receiver-Driven P2MP/ MP2MP LSPSs with P2P and legacy P2MP LSPs within the same network. A solution for the dynamic establishment and maintenance of Receiver- Driven P2MP LSPs MUST be specified in such a way that it allows legacy P2MP and P2P TE LSPs to be signaled on the same interface. 4.6. Advertisement of Leaf Driven mRSVP-TE Capability To facilitate the computation of Receiver-Driven P2MP trees using TE constraints within a network whose LSRs do not all support the same capability level with respect to Receiver-Driven P2MP RSVP-TE signaling and data forwarding, the capability of an LSR to support the RSVP-TE signaling and forwarding for Receiver-Driven P2MP LSPs MUST be advertised to its neighbor LSRs. 4.7. Scalability Scalability is a key requirement in mRSVP-TE systems. Solutions MUST be designed to scale well as a function of the number of any of the following: o the number of receivers o the number of sources Jacquenet & Zhao Expires September 13, 2012 [Page 12] Internet-Draft RD mRSVP TE Requirements March 2012 o the number of egress LSRs o the number of branch LSRs o the number of branches Furthermore, scalability of control plane operation (setup, maintenance, modification, and teardown) MUST be considered. Key considerations MUST include: o The amount of refresh processing associated with maintaining a P2MP/MP2MP TE LSP. o The amount of protocol state that must be maintained by ingress and transit LSRs along a P2MP/MP2MP tree. o The number of protocol messages required to set up or tear down a P2MP/MP2MP LSP as a function of the number of egress LSRs. o The number of protocol messages required to repair a P2MP/MP2MP LSP after failure or to perform make-before-break. o The amount of protocol information transmitted to manage a P2MP/ MP2MP TE LSP (i.e., the message size). o The amount of additional data distributed in potential routing extensions. o The amount of additional control plane processing required in the network to detect whether an add/delete of a new branch is required, and in particular, the amount of processing in steady state when no add/delete is requested. o The amount of control plane processing required by the ingress, transit, and egress LSRs to add/delete a branch LSP to/from an existing P2MP LSP. It is expected that the applicability of each solution will be evaluated with regards to the aforementioned scalability criteria. In order to accommodate a growing number of leaves, it is RECOMMENDED that the amount of a P2MP LSP/MP2MP state on a LSR, for one particular LSP, depends only on the number of adjacent LSRs on the LSP. Jacquenet & Zhao Expires September 13, 2012 [Page 13] Internet-Draft RD mRSVP TE Requirements March 2012 4.8. Variation of LSP Parameters Certain parameters (such as priority and bandwidth) are associated with an LSP. The parameters are installed by the signaling exchanges associated with the establishment and the maintenance of the P2MP/ MP2MP LSP. Any solution MUST NOT allow for variance of these parameters within a single P2MP/MP2MP LSP. That is: o Downstream or upstream LSRs MUST NOT alter the attributes set and signaled by a first leaf router of a P2MP/MP2MP tree structure. o A consistent QoS policy SHOULD be enforced from the root to all leaves of a single P2MP/MP2MP LSP. o Some leaves of a given tree may yield the enforcement of a different QoS policy, depending on the various access capabilities of the receivers. Still, content will be delivered to these receivers by using the same (core) P2MP/MP2MP tree structure. o Changing the parameters for the whole tree MAY be supported, but the change MUST apply to the whole tree from ingress LSR to all egress LSRs. 5. In-Band Signalling TBD. 6. Backwards Compatibility Any P2MP/MP2MP TE LSP solution SHOULD offer as much backward compatibility as possible. Also, RD P2MP TE LSPs MUST be able to coexist with IP unicast and IP multicast networks. 7. Acknowledgements We would like to thank authors of [RFC4461] and the authors of [RFC6348] from which some text of this document has been inspired. 8. IANA Considerations This memo includes no request to IANA. Jacquenet & Zhao Expires September 13, 2012 [Page 14] Internet-Draft RD mRSVP TE Requirements March 2012 9. Security Considerations This document does not define any protocol extensions and does not, therefore, make any changes to any security models. It is a requirement that any RD P2MP/MP2MP solution developed to meet some or all of the requirements expressed in this document MUST include mechanisms to enable the secure establishment and management. of P2MP/MP2MP RSVP-TE LSPs. This includes, but is not limited to: o A receiver MUST be authenticated before it is allowed to trigger the establishment of an additional leaf of a RD P2MP LSP tree structure, in addition to hop-by-hop security issues identified in RFC 3209 and RFC 4206. o mechanisms that provide some guarantees about the identity of an ingress LSR of a P2MP/MP2MP LSP; o mechanisms to ensure that communicating signaling entities can verify each other's identities; o mechanisms to ensure that control plane messages are protected against spoofing and tampering; o mechanisms to ensure that unauthorized leaves or branches are not added to the P2MP/MP2MP LSP; and mechanisms to protect signaling messages from snooping. o Note that RD P2MP/MP2MP signaling mechanisms built on P2P RSVP-TE signaling and RSVP-TE P2MP signalling are likely to inherit all the security techniques and problems associated with RSVP-TE. These problems may be exacerbated in P2MP/MP2MP situations where security relationships may need to be maintained between an ingress LSR and multiple egress LSRs. Such issues are similar to security issues for IP multicast. 10. References 10.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Awduche, D., Malcolm, J., Agogbua, J., O'Dell, M., and J. McManus, "Requirements for Traffic Engineering Over MPLS", RFC 2702, September 1999. [3] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Jacquenet & Zhao Expires September 13, 2012 [Page 15] Internet-Draft RD mRSVP TE Requirements March 2012 Switching Architecture", RFC 3031, January 2001. [4] 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. [5] Yasukawa, S., "Signaling Requirements for Point-to-Multipoint Traffic-Engineered MPLS Label Switched Paths (LSPs)", RFC 4461, April 2006. [6] 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. [7] Farrel, A., Papadimitriou, D., Vasseur, J., and A. Ayyangar, "Encoding of Attributes for Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) Establishment Using Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)", RFC 4420, February 2006. [8] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. [9] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [10] Pan, P., Swallow, G., and A. Atlas, "Fast Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090, May 2005. [11] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [12] Aggarwal, R. and J. Roux, "MPLS Upstream Label Assignment for RSVP-TE", draft-ietf-mpls-rsvp-upstream-05 (work in progress), March 2010. [13] Roux, J. and T. Morin, "Requirements for Point-To-Multipoint Extensions to the Label Distribution Protocol", draft-ietf-mpls-mp-ldp-reqs-08 (work in progress), May 2011. [14] Aggarwal, R. and E. Rosen, "Multicast in MPLS/BGP IP VPNs", draft-ietf-l3vpn-2547bis-mcast-10 (work in progress), January 2010. Jacquenet & Zhao Expires September 13, 2012 [Page 16] Internet-Draft RD mRSVP TE Requirements March 2012 10.2. Informative References [15] Andersson, L. and G. Swallow, "The Multiprotocol Label Switching (MPLS) Working Group decision on MPLS signaling protocols", RFC 3468, February 2003. [16] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [17] Le Faucheur, F. and W. Lai, "Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering", RFC 3564, July 2003. [18] Berger, L., Takacs, A., Caviglia, D., Fedyk, D., and J. Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label Switched Paths (LSPs)", RFC 5467, March 2009. Authors' Addresses Christian Jacquenet France Telecom Orange 4 rue du Clos Courtel 35512 Cesson Sevigne France Phone: +33 2 99 12 43 82 Email: christian.jacquenet@orange-ftgroup.com Quintin Zhao Huawei Technology 125 Nagog Park Acton, MA 01919 US Phone: Email: qzhao@huawei.com Jacquenet & Zhao Expires September 13, 2012 [Page 17]