Network Working Group Internet Draft K. Kumaki, Ed. Category: Informational KDDI Corporation Created: November 19, 2007 R. Zhang Expires: May 19, 2008 BT Requirements for supporting Customer RSVP and RSVP-TE Over a BGP/MPLS IP-VPN draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract Recently some service providers try to build a converged network as a next generation network (NGN) and provide a service which guarantees a bandwidth from a local CE to a remote CE through the network. Today, customers expect triple play services through BGP/MPLS IP-VPNs. And their requirements for end-to-end QoS and session management of applications are increasing. Depending on an application, an end-to- K.Kumaki, et al. [Page 1] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 end native RSVP path and an end-to-end MPLS TE LSP are required and they need to meet with some constraint requirements. This document describes Service Provider requirements for supporting customer RSVP and RSVP-TE over a BGP/MPLS VPN. 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 [RFC2119]. Table of Contents 1. Introduction..................................................3 2. Terminology...................................................3 3. Problem Statement.............................................4 4. Reference model...............................................5 5. Application Scenarios..........................................7 5.1 Scenario I: Fast recovery over BGP/MPLS IP-VPN.............7 5.2 Scenario II: Strict C-TE LSP QoS guarantees................7 5.3 Scenario III: load balance of CE-to-CE traffic.............8 5.4 Scenario IV: RSVP Aggregation over MPLS TE Tunnels.........9 6. Detailed Requirements.........................................10 6.1 Selective P-TE LSPs.....................................10 6.2 Graceful Restart Support for C-TE LSPs..................10 6.3 Rerouting Support for C-TE LSPs.........................11 6.4 FRR Support for C-TE LSPs...............................11 6.5 Admission Control Support on P-TE LSP Head-Ends.........11 6.6 Policy Control Support for C-TE LSPs....................11 6.7 PCE Features Support for C-TE LSPs......................12 6.8 Diversely Routed C-TE LSPs Support......................12 6.9 Optimal Path Support for C-TE LSPs......................12 6.10 Reoptimization Support for C-TE LSPs....................12 6.11 DS-TE Support for C-RSVP paths and C-TE LSPs............13 6.12 CE-PE Routing...........................................13 6.13 RSVP requirements.......................................13 6.14 Complexity and Risks....................................13 6.15 Backward Compatibility..................................13 6.16 Scalability Considerations..............................14 6.17 Performance Considerations..............................14 6.18 Management Considerations...............................14 7. Security Considerations......................................15 8. IANA Considerations..........................................15 9. Normative References.........................................15 10.Informative References........................................16 11.Acknowledgments...............................................16 12.Author's Addresses............................................16 13.Intellectual Property Statement...............................17 K.Kumaki, et al. [Page 2] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 1. Introduction Recently some service providers want to build a converged network as a next generation network (NGN) and provide a service which guarantees a bandwidth from a local CE to a remote CE through the network. Today, customers expect triple play services through BGP/MPLS IP-VPNs [RFC4364]. And their requirements for end-to-end QoS and session management of applications are increasing. Depending on an application (e.g., voice, television, video and so on), an end-to-end native RSVP path and an end-to-end MPLS TE LSP are required and they need to meet with some constraint requirements. For example, an end- to-end native RSVP path satisfies to guarantee a bandwidth, and an end-to-end MPLS TE LSP satisfies to guarantee a bandwidth, to support FRR features [RFC4090] and to support an optimal path. If service providers offer the above applications in BGP/MPLS IP-VPNs, they have the following two advantages. The first advantage is for customers to be able to use both private addresses and global addresses without limiting to the way of assigning addresses. This is because service providers can assign both private addresses and global addresses which a customer wants. The second advantage is for service providers to be able to protect confidentiality from customers. This is because customers join a Virtual Routing and Forwarding (VRF) instance. Customers cannot forward packets through the service provider's general forwarding instance, nor can they join the service provider's intra-domain routing or MPLS signaling domain. Thus, it is highly desirable that some triple play services are provided for existing customers and new customers by expanding the existing BGP/MPLS IP-VPNs. This document defines reference model, application scenarios and detailed requirements for supporting customer RSVP and RSVP-TE over a BGP/MPLS IP-VPN. Also, specification for this solution itself is out of scope in this document. 2. Terminology LSP: Label Switched Path TE LSP: Traffic Engineering Label Switched Path MPLS TE LSP: Multi Protocol Label Switching TE LSP K.Kumaki, et al. [Page 3] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 C-RSVP path: Customer RSVP path: a native RSVP path with bandwidth reservation of X for customers C-TE LSP: Customer Traffic Engineering Label Switched Path: an end-to-end MPLS TE LSP for customers P-TE LSP: Provider Traffic Engineering Label Switched Path: a transport TE LSP between PEs for service providers VPN: Virtual Private Network CE: Customer Edge Equipment PE: Provider Edge Equipment that has direct connections to CEs from the Layer3 point of view. P: Provider Equipment that has backbone trunk connections only. VRF: Virtual Private Network (VPN) Routing and Forwarding Instance PCC: Path Computation Client: any client application requesting a path computation to be performed by a Path Computation Element. PCE: Path Computation Element: an entity (component, application or network node) that is capable of computing a network path or route based on a network graph and applying computational constraints. Head-end LSR: ingress LSR Tail-end LSR: egress LSR LSR: Label Switched Router 3. Problem Statement Some service providers think that they offer advanced services using RSVP or RSVP-TE over BGP/MPLS IP-VPN. Service providers have some application scenarios for these services. For example, a C-RSVP path with bandwidth reservation of X is required for voice and a C-TE LSP with guaranteed bandwidth between data center or customer sites is required for voice, television and video. Because traffic such as voice, television and video is very sensitive, it is required to ensure sub-50msec recovery in link/node/SRLG, strict QoS guarantees and optimal path depending on services. Thus, service providers or customers can choose a C-RSVP path or a C-TE LSP depending on services. K.Kumaki, et al. [Page 4] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 If service providers offer a C-RSVP path between hosts or CEs over BGP/MPLS IP-VPN, they require that a C-RSVP path from a local host to a remote host is established. The host requests to remote host an end-to-end C-RSVP path with bandwidth reservation of X. This reservation request from within the context of VRF gets aggregated onto a pre-established P-TE LSP. One of solutions is described in [RSVP-L3VPN]. Also, if service providers offer a C-TE LSP from CE to CE over BGP/MPLS IP-VPN, they require that a MPLS TE LSP from a local CE to a remote CE is established. In order to maintain a separation between customer addressing and routing and provider addressing and routing, service providers want to offer this service over BGP/MPLS IP-VPN [RFC4364], that maintain the customer site to site routing. But if service providers provide the C-TE LSP over a BGP/MPLS IP-VPN, they can't provide it over vrf instance as defined in RFC4364. The current BGP/MPLS IP-VPN architecture does not include an RSVP-TE instance running in the context of a vrf to process RSVP messages and trigger the establishment of the C-TE LSP over the service provider core network. Furthermore, there is a possibility that these C-TE LSPs are provided every specific application such as voice, television and video. In this way, service providers must maintain quite a few C-TE LSPs. But, a C-TE LSP established over BGP/MPLS IP-VPN is not scalable due to the number of RSVP control message and retained state because it may result in a lot of MPLS TE LSPs in an actual BGP/MPLS IP-VPN. Therefore, scalable C-TE LSPs are required through BGP/MPLS IP-VPN. This problem happens in carrier's carrier environments [RFC4364] as well as in basic BGP/MPLS IP-VPN environments. The following items are mainly required to support C-RSVP paths and C-TE LSPs over BGP/MPLS IP-VPN. - C-RSVP path QoS guarantees. - Fast recovery over BGP/MPLS IP-VPN to protect traffic for C-TE LSP against CE-PE link failure and PE node failure. - Strict C-TE LSP QoS guarantees. - Resource optimization for C-RSVP paths and C-TE LSPs. - Scalability for C-TE LSPs. 4. Reference model This section describes a C-RSVP path, a C-TE LSP and a P-TE LSP in BGP/MPLS IP-VPN. In BGP/MPLS IP-VPN, a C-RSVP path, a C-TE LSP and a P-TE LSP are shown in figure 1. K.Kumaki, et al. [Page 5] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 CE0 and/or CE1 request an e2e C-RSVP path with bandwidth reservation of X to CE2 and/or CE3 respectively. This reservation request from within the context of VRF will get aggregated onto a pre-established P-TE LSP. CE0 and/or CE1 send a path message to CE2 and/or CE3 respectively over vrf instance. The rsvp control messages (i.e. a RSVP PATH message and a RSVP RESV message and so on) are forwarded by labeled packet through BGP/MPLS IP-VPN. After CE0 and/or CE1 receive a reservation message from CE2 and/or CE3, it establishes a C-TE LSP through BGP/MPLS IP-VPN. A P-TE LSP is established between PE1 and PE2. This LSP is used by vrf instance to forward customer packets within BGP/MPLS IP-VPN. Generally speaking, C-RSVP paths and C-TE LSPs are used by customers and P-TE LSPs are used by service providers. C-RSVP path <----------------------------------------------> or C-TE LSP <-----------------------------------------------------------> or C-TE LSP <----------------------------------------------> P-TE LSP <---------------------------> ............. ............. . --- --- . --- --- --- --- . --- --- . .|CE0| |CE1|-----|PE1|----|P1 |-----|P2 |----|PE2|-----|CE2| |CE3|. . --- --- . --- --- --- --- . --- --- . ............. ............. ^ ^ | | vrf instance vrf instance <--customer--> <--------BGP/MPLS IP-VPN-------> <--customer-> network network or or another another service provider service provider network network K.Kumaki, et al. [Page 6] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 Figure 1 Reference Model 5. Application Scenarios The following sections present a few application scenarios for C-RSVP paths and C-TE LSPs in BGP/MPLS IP-VPN environments. 5.1 Scenario I: Fast recovery over BGP/MPLS IP-VPN In this scenario, a customer uses a VoIP application between its sites (i.e., between CE1 and CE2). H0 and H1 are voice equipments. This scenario I is shown in figure 2. In this case, the customer establishes C-TE LSP1 which is a primary path and C-TE LSP2 which is a backup path. If the link between PE1 and CE1 or the node (i.e., PE1) fails, C-TE LSP1 needs a path protection. C-TE LSP1 <----------------------------------------------> P-TE LSP1 <---------------------------> ............. ............. . --- --- . --- --- --- --- . --- --- . .|H0 | |CE1|-----|PE1|----|P1 |-----|P2 |----|PE2|-----|CE2| |H1 |. . --- --- . --- --- --- --- . --- --- . .........|... --- --- --- --- ...|......... +-------|PE3|----|P3 |-----|P4 |----|PE4|-------+ --- --- --- --- <---------------------------> P-TE LSP2 <----------------------------------------------> C-TE LSP2 <--customer--> <--------BGP/MPLS IP-VPN-------> <--customer-> network network Figure 2 Scenario I 5.2 Scenario II: Strict C-TE LSP QoS guarantees In this scenario, service provider B controls voice, video and television traffic between its sites (i.e., between CE1 and CE2). This scenario II is shown in figure 3. In this case, service provider B establishes C-TE LSP1 with preemption priority 0, available bandwidth 100Mbps for voice traffic and C-TE LSP2 with preemption priority 1, available bandwidth 200Mbps for video and television traffic. On the other hand, service provider A also pre-establishes P-TE LSP1 with preemption priority 0, available bandwidth 1Gbps for voice traffic and P-TE LSP2 with K.Kumaki, et al. [Page 7] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 preemption priority 1, available bandwidth 2Gbps for video and television traffic. These P-TE LSP1 and P-TE LSP2 should support DS- TE. [RFC4124] PE1 and PE3 should choose an appropriate P-TE LSP based on preemption priority. In this case, P-TE LSP1 should choose C-TE LSP1 at PE1 and P-TE LSP2 should choose C-TE LSP2 at PE3. Furthermore, PE1 and PE3 head-ends should control the bandwidth of C- TE LSPs. In this case, PE1 and PE3 can choose C-TE LSPs by the amount of max available bandwidth for each P-TE LSP, respectively. C-TE LSP1 <----------------------------------------------> P-TE LSP1 <---------------------------> ............. ............. . --- --- . --- --- --- --- . --- --- . .|CE0| |CE1|-----|PE1|----|P1 |-----|P2 |----|PE2|-----|CE2| |CE3|. . --- --- . --- --- --- --- . --- --- . .........|... --- --- --- --- ...|......... +-------|PE3|----|P3 |-----|P4 |----|PE4|-------+ --- --- --- --- <---------------------------> P-TE LSP2 <----------------------------------------------> C-TE LSP2 <---SP B----> <--------BGP/MPLS IP-VPN-------> <---SP B---> network SP A network network Figure 3 Scenario II 5.3 Scenario III: load balance of CE-to-CE traffic In this scenario, service provider C uses voice, video and television traffic between its sites (i.e., between CE0 and CE5/CE7, between CE2 and CE5/CE7, between CE5 and CE0/CE2, and between CE7 and CE0/CE2). H0 and H1 are voice, video and television equipments. This scenario III is shown in figure 4. In this case, service provider C establishes C-TE LSP1, C-TE LSP3, C- TE LSP5 and C-TE LSP7 with preemption priority 0, available bandwidth 100Mbps for voice traffic, and establishes C-TE LSP2, C-TE LSP4, C-TE LSP6 and C-TE LSP8 with preemption priority 1, available bandwidth 200Mbps for video and television traffic. On the other hand, service provider A also pre-establishes P-TE LSP1 and P-TE LSP3 with preemption priority 0, available bandwidth 1Gbps for voice traffic and P-TE LSP2 and P-TE LSP4 with preemption priority 1, available K.Kumaki, et al. [Page 8] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 bandwidth 2Gbps for video and television traffic. These P-TE LSP1, P- TE LSP2, P-TE LSP3 and P-TE LSP4 should support DS-TE. [RFC4124] All PEs should choose an appropriate P-TE LSP based on preemption priority. To minimize the traffic disruption due to a single network failure, diversely routed C-TE LSPs are established. In this case, FRR [RFC4090] is not necessarily required. Also, unconstrained TE LSPs (i.e., C-TE LSPs/P-TE LSPs with 0 bandwidth) are applicable to this scenario. C-TE LSP1(P=0),2(P=1) (CE0->CE1->...->CE4->CE5) (CE0<-CE1<-...<-CE4<-CE5) <--------------------------------------------------> C-TE LSP3(P=0),4(P=1) (CE2->CE1->...->CE4->CE7) (CE2<-CE1<-...<-CE4<-CE7) <--------------------------------------------------> P-TE LSP1 (p=0) <-----------------------> P-TE LSP2 (p=1) <-----------------------> .................. .................. . --- --- . --- --- --- --- . --- --- . . |CE0|-|CE1|---|PE1|---|P1 |---|P2 |---|PE2|---|CE4|-|CE5| . . --- /--- --- . --- --- --- --- . --- ---\ --- . .|H0 | + . + . + |H1 |. . --- \--- --- . --- --- --- --- . --- ---/ --- . . |CE2|-|CE3|---|PE3|---|P3 |---|P4 |---|PE4|---|CE6|-|CE7| . . --- --- . --- --- --- --- . --- --- . .................. .................. <-----------------------> P-TE LSP3 (p=0) <-----------------------> P-TE LSP4 (p=1) <--------------------------------------------------> C-TE LSP5(P=0),6(P=1) (CE0->CE3->...->CE6->CE5) (CE0<-CE3<-...<-CE6<-CE5) <--------------------------------------------------> C-TE LSP7(P=0),8(P=1) (CE2->CE3->...->CE6->CE7) (CE2<-CE3<-...<-CE6<-CE7) <-----SP C-----> <--------BGP/MPLS IP-VPN-------> <-----SP C-----> network SP A network network Figure 4 Scenario III 5.4 Scenario IV: RSVP Aggregation over MPLS TE Tunnels In this scenario, the customer in this case has two hosts connecting off CE1 and CE2 respectively. CE1 and CE2 are connected to PE1 and K.Kumaki, et al. [Page 9] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 PE2 respectively within a VRF instance belonging to the same VPN. The requesting host (H1) may request to H2 an e2e path with bandwidth reservation of X. This scenario IV is shown in figure 5. This reservation request from within the context of VRF will get aggregated onto a pre-established P-TE/DS-TE LSP based upon procedures similar to [RFC4804]. As in the case of [RFC4804], there may be multiple P-TE LSPs belonging to different DS-TE class-types. Local policies can be implemented to map the incoming RSVP path request from H1 to the P-TE LSP with the appropriate class-type. Please note that the e2e RSVP path request may also be initiated by the CE devices themselves acting as a VoIP codec for example. C-RSVP e2e path <----------------------------------------------> P-TE LSP <---------------------------> ............. ............. . --- --- . --- --- --- --- . --- --- . .|H1 | |CE1|-----|PE1|----|P1 |-----|P2 |----|PE2|-----|CE2| |H2 |. . --- --- . --- --- --- --- . --- --- . ............. ............. ^ ^ | | vrf instance vrf instance Figure 5 Scenario IV 6. Detailed Requirements This section describes detailed requirements for C-RSVP paths and C-T E LSPs in BGP/MPLS IP-VPN environments. 6.1 Selective P-TE LSPs The solution MAY provide the ability to decide which P-TE LSP a PE uses for a C-RSVP path and a C-TE LSP. When a PE receives a native RSVP and a path messages from a CE, it may be able to decide which P- TE LSP it uses. In this case, various kinds of P-TE LSPs exist in service provider network. For example, the PE MAY choose an appropriate P-TE LSP based on local policies such as: 1. preemption priority 2. affinity 3. class-type 4. on the data plane: (DSCP or EXP bits) 6.2 Graceful Restart Support for C-TE LSPs K.Kumaki, et al. [Page 10] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 The solution SHOULD provide graceful restart capability for a C-TE LSP over vrf instance. Graceful restart mechanisms related to this architecture are described in [RFC3473] [RFC3623] [RFC4781]. 6.3 Rerouting Support for C-TE LSPs The solution MUST provide rerouting of a C-TE LSP in case of link/node/SRLG failures or preemption. Such rerouting may be controlled by a CE or by a PE depending on the failure. Rerouting capability MUST be provided against a CE-PE link failure or a PE failure if another is available between the head-end and the tail-end of the C-TE LSP. 6.4 FRR Support for C-TE LSPs The solution MUST support FRR [RFC4090] features for a C-TE LSP over vrf instance. In BGP/MPLS IP-VPN environments, a C-TE LSP from a CE traverses over multiple PEs and Ps, albeit tunneled over a P-TE LSP. In order to avoid PE-CE link/PE node/SRLG failures needs to support a fast local protection or a fast path protection. 6.5 Admission Control Support on P-TE LSP Head-Ends The solution MUST support admission control on a P-TE LSP tunnel head-end. C-TE LSPs may potentially reserve over the bandwidth of a P-TE LSP. The P-TE LSP tunnel head-end SHOULD control the number of C-TE LSPs or the bandwidth of C-TE LSPs. For example, the transport TE LSP head-end MUST have a configurable limit on the maximum number of C-TE LSPs that it can admit. As for the amount of bandwidth that can be reserved by C-TE LSPs: there could be two situations: 1. Let the P-TE LSP do its natural bandwidth admission 2. Set a cap on the amount of bandwidth and have the configuration option to: a. Reserve the minimum of the cap bandwidth or the C-TE LSP bandwidth on the P-TE LSP if that required bandwidth is available b. Reject the C-TE LSP if the required bandwidth by the C-TE LSP is not available 6.6 Policy Control Support for C-TE LSPs The solution MAY support policy control for a C-TE LSP at a PE. A PE receives RSVP control messages from a CE. The PE has the possibility that receives unexpected packets from the CE site. The PE MAY control RSVP control messages per vrf instance. Especially, if a CE is not managed by service providers, the PE has the high possibility that receives unexpected packets from the CE site. K.Kumaki, et al. [Page 11] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 In this case, the PE should control RSVP control messages per vrf instance. In case that a transport TE LSP tunnel head-end controls the bandwidth of C-TE LSPs, an ingress policy can be applied on the customer facing interface on the PE to control the max reservable resources. Furthermore, PEs cooperated with Operating Support System (OSS) interpret a bandwidth customers require and may assign a bandwidth for a customer. 6.7 PCE Features Support for C-TE LSPs The solution MAY support PCE features for a C-TE LSP over vrf instance. When a C-TE LSP is provided, CEs, PEs and Ps may support PCE [RFC4655] [PCEP] features. In this case, CE routers or PE routers have PCC functions and PE routers and/or P routers have PCE functions. 6.8 Diversely Routed C-TE LSPs Support The solution SHOULD set up a diversely routed C-TE LSP over vrf instance. When a single CE has multiple uplinks which connect to different PEs, it is desirable that multiple C-TE LSPs over vrf instance are established between a pair of LSRs. When two CEs have multiple uplinks which connect to different PEs, it is desirable that multiple C-TE LSPs over vrf instance are established between two different pairs of LSRs. In these cases, for example, the following points will be beneficial to customers. - load balance of CE-to-CE traffic across diverse C-TE LSP so as to minimize the traffic disruption in case of a single network element failure - path protection (e.g. 1:1, 1:N) 6.9 Optimal Path Support for C-TE LSPs The solution MUST support an optimal path of a C-TE LSP over vrf instance. Depending on an application (e.g. voice, television and video), an optimal path is needed for a C-TE LSP over vrf instance. An optimal path may be a shortest path based on TE metric or IGP metric. 6.10 Reoptimization Support for C-TE LSPs The solution MUST support reoptimization of a C-TE LSP over vrf instance. K.Kumaki, et al. [Page 12] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 These LSPs must be reoptimized by make-before-break. In this case, it is desirable for a head-end LSR to be configured with regard to timer-based or event-driven reoptimization. Furthermore, customers should be able to reoptimize a C-TE LSP manually. To provide delay- or jitter-sensitive traffic (i.e. voice traffic), a C-TE LSP should be optimally established. 6.11 DS-TE Support for C-RSVP paths and C-TE LSPs The solution SHOULD support DS-TE [RFC4124] features for a C-RSVP path and a C-TE LSP over vrf instance. Applications, which have different traffic characteristics, are used in BGP/MPLS IP-VPN environments. Service providers try to achieve fine-grained optimization of transmission resources, efficiency and further enhanced network performance. It may be desirable to perform TE at a per-class level. By mapping the traffic from a given diff-serv class of service on a separate LSP, it allows this traffic to utilize resources available to the given class on both shortest paths and non-shortest paths, and follow paths that meet TE constraints which are specific to the given class. Requirements for DS-TE are described in [RFC3564]. 6.12 CE-PE Routing The solution MUST support the following routing configuration on the CE-PE links with either RSVP or RSVP-TE on the CE-PE link: 1- static routing 2- BGP routing 3- OSPF 4- OSPF-TE 6.13 RSVP requirements Requirements for RSVP on the PE-CE link will be included in a future update of this document. 6.14 Complexity and Risks The solution SHOULD NOT introduce unnecessary complexity to the current operating network to such a degree that it would affect the stability and diminish the benefits of deploying such a solution over SP networks. 6.15 Backward Compatibility The deployment of C-RSVP paths and C-TE LSPs SHOULD NOT impact existing RSVP and MPLS TE mechanisms respectively, but allow for a smooth migration or co-existence. K.Kumaki, et al. [Page 13] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 6.16 Scalability Considerations The solution MUST have a minimum impact on network scalability from a C-RSVP path and a C-TE LSP over vrf instance. Scalability of C-RSVP paths and C-TE LSPs MUST addresses the following consideration. - RSVP (e.g. number of RSVP messages, retained state and so on). - RSVP-TE (e.g. number of RSVP control messages, retained state, message size and so on). - BGP (e.g. number of routes, flaps, overloads events and so on). If the number of required C-TE LSPs increases, there would be scalability issues. In this case, PEs may support a hierarchical LSP [RFC4206]. 6.17 Performance Considerations The solution SHOULD be evaluated with regard to the following criteria. - Degree of path optimality of the C-TE LSP. - TE LSP setup time. - Failure and restoration time. - Impact and scalability of the control plane due to added overheads and so on. - Impact and scalability of the data/forwarding plane due to added overheads and so on. 6.18 Management Considerations Manageability of C-RSVP paths and C-TE LSPs MUST addresses the following considerations for section 5. - Need for a MIB module for control plane and monitoring. - Need for diagnostic tools. MIB module for C-TE LSPs MUST collect per a vrf instance. If a CE is managed by service providers, MIB information for C-TE LSPs from the CE MUST be collected per a customer. Today, diagnostic tools can detect failures of control plane and data plane for general MPLS TE LSPs [RFC4379]. The diagnostic tools MUST detect failures of control and data plane for C-TE LSPs over a vrf instance. MPLS OAM for C-TE LSPs MUST be supported within the context of VRF except for the above. K.Kumaki, et al. [Page 14] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 In BGP/MPLS IP-VPN environments, from a CE point of view, IP TTL decreases at a local PE and a remote PE. But from a PE point of view, both IP TTL and MPLS TTL decreases between PEs. 7. Security Considerations Security issues for C-TE LSPs relate to both control plane and data plane. In terms of control plane, a PE receives IPv4 or IPv6 RSVP control packets from a CE. If the CE is an untrusted router for service providers, the PE MUST be able to control IPv4 or IPv6 RSVP control packets. If the CE is a trusted router for service providers, the PE MAY be able to control IPv4 or IPv6 control packets. In terms of data plane, a PE receives labeled IPv4 or IPv6 data packets from a CE. If the CE is an untrusted router for service providers, the PE MUST be able to control labeled IPv4 or IPv6 data packets. If the CE is a trusted router for service providers, the PE MAY be able to control labeled IPv4 or IPv6 data packets. In BGP/MPLS IP-VPN environments, from a CE point of view, IP TTL should decrease at a local PE and a remote PE to hide service provider network topology. 8. IANA Considerations This requirement document makes no requests for IANA action. 9. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions ", RFC 3473, January 2003. [RFC3564] Le Faucheur, F., and Lai, W., "Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering ", RFC 3564, July 2003. [RFC3623] Moy, J., et al., "Graceful OSPF Restart", RFC3623, November 2003. [RFC4090] Pan, P., Swallow, G. and A. Atlas, "Fast Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090, May 2005. K.Kumaki, et al. [Page 15] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of Diffserv-aware MPLS Traffic Engineering", RFC 4124, June 2005. [RFC4206] Kompella, K., and Rekhter, Y., "Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. [RFC4364] Rosen, E., and Rekhter, Y., "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, February 2006. [RFC4379] Kompella, K. and G. Swallow, "Detecting MPLS Data Plane Failures", RFC 4379, February 2006. [RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "Path Computation Element (PCE) Architecture", RFC 4655, August 2006. [RFC4781] Rekhter, Y., and Aggarwal, R., "Graceful Restart Mechanism for BGP with MPLS", RFC 4781, January 2007. 10.Informative References [RSVP-L3VPN] Davie, B., et al., "Support for RSVP in Layer 3 VPNs", Work in Progress, June 2007. [PCEP] Vasseur, J.-P., et al., "Path Computation Element(PCE) communication Protocol (PCEP) - Version 1", Work in Progress, February 2007. [RFC4804] Le Faucheur, F., et al., "Aggregation of RSVP Reservations over MPLS TE/DS-TE Tunnels", RFC4804, February 2007. 11.Acknowledgments The author would like to express the thanks to Ron Bonica, Koh Yamashita, Miya Kohno, Tomohiro Otani for their helpful and useful comments and feedback. 12.Author's Addresses Kenji Kumaki (Editor) KDDI Corporation Garden Air Tower Iidabashi, Chiyoda-ku, Tokyo 102-8460, JAPAN Email: ke-kumaki@kddi.com K.Kumaki, et al. [Page 16] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 Raymond Zhang BT Infonet 2160 E. Grand Ave. El Segundo, CA 90025 Email: raymond.zhang@bt.infonet.com 13.Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein 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 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgement K.Kumaki, et al. [Page 17] draft-kumaki-l3vpn-e2e-rsvp-te-reqts-05 November 2007 Funding for the RFC Editor function is currently provided by the Internet Society. K.Kumaki, et al. [Page 18]