Network Working Group K. Shiomoto (Ed.) Internet Draft NTT Updates: 3477, 4206 A. Farrel (Ed.) Proposed Category: Proposed Standard Old Dog Consulting Created: October 15, 2008 Expires: April 15, 2008 Procedures for Dynamically Signaled Hierarchical Label Switched Paths draft-ietf-ccamp-lsp-hierarchy-bis-04.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 Abstract Label Switched Paths (LSPs) set up in Multiprotocol Label Switching (MPLS) or Generalized MPLS (GMPLS) networks can be used to form links for carrying traffic in those networks or in other (client) networks. Protocol extensions already exist to facilitate the establishment of an LSP as a numbered traffic engineering (TE) link within the same instance of the routing as is used to advertise the links that it traverses creating a Forwarding Adjacency (FA). This document extends those mechanisms to support unnumbered FAs. This document also defines how to indicate that an LSP should be advertised as a link in another instance of the routing protocol (for instance in a client network) and which instance to use. Furthermore, mechanisms are defined to indicate when an LSP is to be used as a component link of a TE link bundle and to identify the bundle. Shiomoto and Farrel Expires April 2009 [Page 1] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 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 and Problem Statement ............................. 1 1.1. Background ................................................... 1.1.1. Hierarchical LSPs .......................................... 1.1.2. LSP Stitching Segments ..................................... 1.1.3. Private Links .............................................. 1.1.4. Routing Adjacencies ........................................ 1.1.5. Forwarding Adjacencies ..................................... 1.1.5. Client/Server Networks ..................................... 1.1.6. Link Bundles ............................................... 1.2. Desired Function ............................................. 1.3. Existing Mechanisms .......................................... 1.3.1. LSP Setup .................................................. 1.3.2. Routing Adjacency Establishment and Link State Advertisement 1.3.3. TE Link Advertisement ...................................... 1.3.4. Configuration and Management Techniques .................... 1.3.5. Signaled Unnumbered FAs .................................... 1.3.6. Establishing Numbered FAs Through Signaling and Routing .... 1.4. Overview of Required Extensions .............................. 1.4.1. Efficient Signaling of Numbered FAs ........................ 1.4.2. LSPs for Use as Private Links .............................. 1.4.3. Signaling an LSP For use in Another Network ................ 1.4.4. Signaling an LSP for Use in a Link Bundle .................. 1.4.5. Support for IPv4 and IPv6 .................................. 1.4.6. Backward Compatibility ..................................... 2. Overview of Solution ........................................... 2.1. Common Approach for Numbered and Unnumbered Links ............ 2.2. LSP Usage Indication ......................................... 2.3. IGP Instance Identification .................................. 2.4. Link Bundle Identification ................................... 2.5. Backward Compatibility ....................................... 3. Mechanisms and Protocol Extensions ............................. 3.1. LSP_TUNNEL_INTERFACE_ID Object ............................... 3.1.1. Existing Definition and Usage .............................. 3.1.2. Unnumbered Links with Action Identification ................ 3.1.3. IPv4 Numbered Links with Action Identification ............. 3.1.4. IPv6 Numbered Links with Action Identification ............. 3.2. Target IGP Identification TLV ................................ 3.3. Component Link Identification TLV ............................ 3.3.1. Unnumbered Component Link Identification ................... 3.3.2. Numbered Component Link Identification ..................... Shiomoto and Farrel Expires April 2009 [Page 2] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 3.4. Link State Advertisement ..................................... 3.5. Message Formats .............................................. 3.6. Error Cases and Non-Acceptance ............................... 3.7. Backward Compatibility ....................................... 4. Security Considerations ........................................ 5. IANA Considerations ............................................ 5.1. New Class Types .............................................. 5.2. Hierarchy Actions ............................................ 5.3. New Error Codes and Error Values ............................. 6. Acknowledgements ............................................... 7. References ..................................................... 7.1. Normative References ......................................... 7.2. Informative References ....................................... 8. Editors' Addresses ............................................. 9. Authors' Addresses ............................................. 1. Introduction and Problem Statement [RFC4206] defines how to set up Label Switched Paths (LSPs) in Generalized Multiprotocol Label Switching (GMPLS) Traffic Engineering (TE) networks to be used as hierarchical Label Switched Paths (H-LSPs). [RFC4201] describes how to collect together TE links between the same pair of nodes and advertise them as a single TE link called a link bundle. [RFC5212] presents a framework and requirements for multilayer networks (MLNs). This includes the establishment of an LSP in a server network that is used as a link in a client network. As set out later in this document, issues have been identified during deployment with how LSPs are established and made available for use as H-LSPs or as components of a link bundle and advertised appropriately in an interior gateway protocol (IGP). These issues relate to coordinating between the LSP's end points the use to which the LSP is put. This document gives some basic background, describes the requirements, sets out the mechanisms that already exist, and enumerates the protocols extensions and mechanisms that are needed. The document goes on to present the necessary additions to the GMPLS protocols. Shiomoto and Farrel Expires April 2009 [Page 3] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 1.1. Background 1.1.1. Hierarchical LSPs [RFC3031] describes how Multiprotocol Label Switching (MPLS) labels may be stacked so that LSPs may be nested with one LSP running through another. This concept of H-LSPs is formalized in [RFC4206] with a set of protocol mechanisms for the establishment of an H-LSP that can carry one or more other LSPs. [RFC4206] goes on to explain that an H-LSP may carry other LSPs only according to their switching types. This is a function of the way labels are carried. In a packet switch capable (PSC) network, the H-LSP can carry other PSC LSPs using the MPLS label stack. In non- packet networks where the label is implicit, label stacks are not possible and rely on the ability to nest switching technologies. Thus, for example, a lambda switch capable (LSC) LSP can carry a time division multiplexing (TDM) LSP, but cannot carry another LSC LSP. Signaling mechanisms defined in [RFC4206] allow an H-LSP to be treated as a single hop in the path of another LSP (i.e., one hop of the LSP carried by the H-LSP). This mechanism is known as "non- adjacent signaling." 1.1.2. LSP Stitching Segments LSP stitching is defined in [RFC5150]. It enables LSPs of the same switching type to be included (stitched) as hops in an end-to-end LSP. The stitching LSP (S-LSP) is used in the control plane in the same way as an H-LSP, but in the data plane the LSPs are stitched so that there is no label stacking or nesting of technologies. Thus, an S-LSP must be of the same switching technology as the end-to-end LSP that it facilitates. 1.1.3. Private Links An H-LSP or S-LSP can be used as a private link. Such links are known by their end-points, but are not more widely known. They can be used to carry traffic between the end-points, but are not usually used to carry traffic that is going beyond the egress of the LSP. 1.1.4. Routing Adjacencies A routing adjacency is formed between two IGP-speakers that are logically adjacent. In this sense, 'logically adjacent' means that the routers have a protocol tunnel between them through which they can exchange routing protocol messages. The tunnel is also usually available for carrying IP data although a distinction should be made in GMPLS networks between data plane traffic and control plane traffic. Shiomoto and Farrel Expires April 2009 [Page 4] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 Routing adjacencies for forwarding data traffic are only relevant in PSC networks (i.e., IP/MPLS networks). 1.1.5. Forwarding Adjacencies A Forwarding Adjacency (FA) is defined in [RFC4206] as a data link created from an LSP and advertised in the same instance of the control plane that advertises the TE links from which the LSP is constructed. The LSP itself is called an FA-LSP. Thus, an H-LSP or S-LSP may form an FA such that it is advertised as a TE link in the same instance of the routing protocol as was used to advertise the TE links that the LSP traverses. As observed in [RFC4206] the nodes at the ends of an FA would not usually have a routing adjacency. 1.1.5. Client/Server Networks An LSP may be created in one network and used as a link (sometimes called a virtual link) in another networks [RFC5212]. In this case the networks are often referred to as server and client networks respectively. The server network LSP is used as an H-LSP or an S-LSP as described above, but does not form an FA because the client and server networks run separate instances of the control plane routing protocols. The virtual link may be used in the client network as a private link or may be advertised in the client network IGP. Additionally, the link may be used in the client network to form a routing adjacency and/or as a TE link. 1.1.6. Link Bundles [RFC4201] recognizes that a pair of adjacent routers may have a large number of TE links that run between them. This can be a considerable burden to the operator who may need to configure them, and to the IGP that must distribute information about each of them. A TE link bundle is defined by [RFC4201] as a TE link that is advertised as an aggregate of multiple TE links that could have been advertised in their own right. All TE links that are collected into a TE link bundle have the same TE properties. Thus, a link bundle is a shorthand that improves the scaling properties of the network. Since a TE link may, itself, be an LSP (either an FA or a virtual link), a link bundle may be constructed from FA-LSPs or virtual links. Shiomoto and Farrel Expires April 2009 [Page 5] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 1.2. Desired Function It should be possible to signal an LSP and automatically coordinate its use and advertisement in any of the ways described in Section 1.3 with minimum involvement from an operator. The mechanisms used should be applicable to numbered and unnumbered links, and should not require implementation complexities. 1.3. Existing Mechanisms This section briefly introduces existing protocol mechanisms used to satisfy the desired function described in Section 1.2. 1.3.1. LSP Setup Both unidirectional LSPs and bidirectional LSPs are signaled from the ingress label switching router (LSR) to the egress LSR. That is, the ingress LSR is the initiator, and the egress learns about the LSP through the signaling protocol [RFC3209], [RFC3473]. 1.3.2. Routing Adjacency Establishment and Link State Advertisement Although hosts can discover routers (for example through ICMP [RFC1256]), routing adjacencies are usually configured at both ends of the adjacency. This requires that each router know the identity of the router at the other end of the link connecting the routers, and know that the IGP is to be run on this link. Once a routing adjacency has been established, a pair of routers may use the IGP to share information about the links available for carrying IP traffic in the network. Suitable routing protocols are OSPF version 2 [RFC2328], OSPF version 3 [RFC5340], and IS-IS [RFC1195]. 1.3.3. TE Link Advertisement Extensions have been made to IGPs to advertise TE link properties ([RFC3630], [RFC5329], [RFC5305], [RFC5308], and [ISIS-IPV6-TE]) and also to advertise link properties in GMPLS networks ([RFC4202], [RFC4203], and [RFC5307]). TE link advertisement can be performed by the same instance of the IGP as is used for normal link state advertisement, or can use a separate instance. Furthermore, the ends of a TE link advertised in an IGP do not need to form a routing adjacency. This is particularly the case with FAs as described in Section 1.1.5. Shiomoto and Farrel Expires April 2009 [Page 6] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 1.3.4. Configuration and Management Techniques LSPs are usually created as the result of a management action. This is true even when a control plane is used ? the management action is a request to the control plane to signal the LSP. If the LSP is to be used as an H-LSP or S-LSP, management commands can be used to install the LSP as a link. The link must be defined, interface identifiers allocated, and the end points configured to know about (and advertise, if necessary) the new link. If the LSP is to be used as part of a link bundle, the operator must decide which bundle it forms part of and ensure that that information is configured at the ingress and egress, along with the necessary interface identifiers. These mechanisms are perfectly functional and quite common in MLNs, but require configuration coordination and additional management. They are open to user error and misconfiguration that might result in the LSP not being used (a waste of resources) or the LSP being made available in the wrong way with some impact on traffic engineering. 1.3.5. Signaled Unnumbered FAs [RFC3477] describes how to establish an LSP and to make it available automatically as a TE link in the same instance of the routing protocol as advertises the TE links it traverses, using IPv4-based unnumbered identifiers to identify the new TE link. That is, [RFC3477] describes how to create an unnumbered FA. The mechanism, as defined in Section 3 of [RFC3477], is briefly as follows: - The ingress of the LSP signals the LSP as normal using a Path message, and includes an LSP_TUNNEL_INTERFACE_ID object. The LSP_TUNNEL_INTERFACE_ID object identifies: - The sender's LSR Router ID - The sender's interface ID for the TE link being created - The egress of the LSP responds as normal to accept the LSP and set it up, and includes an LSP_TUNNEL_INTERFACE_ID object. The LSP_TUNNEL_INTERFACE_ID object identifies: - The egress's LSR Router ID - The egress's interface ID for the TE link being created. - Following the exchange of the Path and Resv messages, both the ingress and the egress know that the LSP is to be advertised as a TE link in the same instance of the routing protocol as was used to advertise the TE links that it traverses, and also know the unnumbered interface identifiers to use in the advertisement. Shiomoto and Farrel Expires April 2009 [Page 7] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 [RFC3477] does not include mechanisms to support IPv6-based unnumbered identifiers, nor IPv4 or IPv6 numbered identifiers. 1.3.6. Establishing Numbered FAs Through Signaling and Routing [RFC4206] describes procedures to establish an LSP and to make it available automatically as a TE link that is identified using IPv4 addresses in the same instance of the routing protocol as advertised the TE links it traverses (that is, as a numbered FA). The mechanism, as defined in [RFC4206], is briefly as follows: - The ingress of the LSP signals the LSP as normal using a Path message, and sets the IPv4 tunnel sender address to the IP address it will use to identify its interface for the TE link being created. This is one address from a /31 pair. - The egress of the LSP responds as normal to accept the LSP and set it up. It infers the address that it must assign to identify its interface for the TE link being created as the partner address of the /31 pair. - The ingress decides whether the LSP is to be advertised as a TE link (i.e., as an FA). If so, it advertises the link in the IGP in the usual way. - If the link is unidirectional, nothing more needs to be done. If the link is bidirectional, the egress must also advertise the link, but it does not know that advertisement is required as there is no indication in the signaling messages. - When the ingress's advertisement of the link is received by the egress it must check to see whether it is the egress of the LSP that formed the link. Typically this means: - Check to see if the link advertisement is new - Check to see if the Link-ID address in the received advertisement matches its own TE Router ID - Checks the advertising router ID from the advertisement against the ingress address of each LSPs for which it is the egress - Deduce the LSP that has been advertised as a TE link and issue the corresponding advertisement for the reverse direction. It is possible that some reduction in processing can be achieved by mapping based on the /31 pairing, but nevertheless, there is a fair amount of processing required, and this does not scale well in large networks. No explanation is provided in [RFC4206] of how to create numbered IPv6 FAs. Shiomoto and Farrel Expires April 2009 [Page 8] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 Note that this document deprecates this procedure as explained in Section 1.4.6. 1.4. Overview of Required Extensions This section provides a brief outline of the required protocol extensions. 1.4.1. Efficient Signaling of Numbered FAs The mechanism described in Section 1.3.6. is inefficient. The egress must wait until it receives an advertisement from the ingress before it knows that the LSP is to be installed as a TE link and advertised as an FA. Further, it must parse all received advertisements to determine if any is the trigger for it to advertise an FA. An efficient signaling mechanism is required so that the egress is informed by the ingress during LSP establishment. 1.4.2. LSPs for Use as Private Links There is currently no mechanism by which an ingress can indicate that an LSP is set up for use as a private link. Any attempt to make it a link would currently cause it to be advertised as an FA. A signaling mechanism is needed to identify the use to which an LSP is to be put. 1.4.3. Signaling an LSP For use in Another Network The existing signaling/routing mechanisms are designed for use in the creation of FAs. That is, the TE link created is advertised in the single IGP instance. The numbered TE link mechanism (Section 1.3.6) could, in theory, be used in an MLN with multiple IGP instances if the addressing model is kept consistent across the networks, and if the egress searches all advertisements in all IGP instances. But this is complex and does not work for unnumbered interfaces. A signaling mechanism is required to indicate in which IGP instance the TE link should be advertised. 1.4.4. Signaling an LSP for Use in a Link Bundle A signaling mechanism is required to indicate that an LSP is intended to form a component link of a link bundle, and to identify the bundle and the IGP instance in which the bundle is advertised. Shiomoto and Farrel Expires April 2009 [Page 9] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 1.4.5. Support for IPv4 and IPv6 The protocol mechanisms must support IPv4 and IPv6 numbered and unnumbered TE links. 1.4.6. Backward Compatibility The existing protocol mechanisms for unnumbered FAs as defined in [RFC4206] and [RFC3477] must continue to be supported, and new mechanisms must be devised such that their introduction will not break existing implementations or deployments. Note that an informal survey in the CCAMP working group established that there are no significant deployments of numbered FAs established using the technique described in [RFC4206] and set out in Section 1.3.6. Therefore, this document deprecates this procedure. 2. Overview of Solution This section provides an overview of the mechanisms and protocol extensions defined in this document. Details are presented in Section 3. 2.1. Common Approach for Numbered and Unnumbered Links The LSP_TUNNEL_INTERFACE_ID object [RFC3477] is extended for use for all H-LSPs and S-LSPs whether they form numbered or unnumbered, IPv4 or IPv6 links. Different class-types of the object identify the address type for which it applies. 2.2. LSP Usage Indication The LSP_TUNNEL_INTERFACE_ID object is given flags in a new Actions field to say how the LSP is to be used. The following categories are supported: - LSP is used as an advertised TE link - LSP is used to form a routing adjacency - LSP is used to form an advertised TE link and a routing adjacency - LSP forms a private link and is not advertised 2.3. IGP Instance Identification An optional TLV is added to the LSP_TUNNEL_INTERFACE_ID object to identify the IGP instance into which the link formed by the LSP is to be advertised. If the TLV is absent and the link is to be advertised as indicated by the Actions field, the link is advertised in the same instance of the IGP as was used to advertise the TE links it traverses. Shiomoto and Farrel Expires April 2009 [Page 10] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 2.4. Link Bundle Identification When an LSP is to be used as a component link of a link bundle, the LSP_TUNNEL_INTERFACE_ID object refers to the bundle indicating how the bundle is addressed and used, and a new TLV indicates the component link identifier for the link that the LSP creates. 2.5. Backward Compatibility Backward compatibility has three aspects. - Existing mechanisms for unnumbered FAs described in [RFC3477] and [RFC4206] must continue to work, so that ingress nodes do not have to be updated when egresses are updated. - Existing mechanisms for establishing numbered FAs described in [RFC4206] are safely deprecated by this document as they are not significantly deployed. - New mechanisms must be gracefully rejected by existing egress implementations so that egress nodes do not have to be updated when ingresses are updated. 3. Mechanisms and Protocol Extensions This section defines protocol mechanisms and extensions to achieve the function described in the previous section. 3.1. LSP_TUNNEL_INTERFACE_ID Object The principal signaling protocol element used to achieve all of the required functions is the LSP_TUNNEL_INTERFACE_ID object defined in [RFC3477]. The existing definition and usage continues to be supported as described in the next section. Subsequent sections describe new variants of the object (denoted by new Class Types), and additional information carried in the object by means of extensions. 3.1.1. Existing Definition and Usage This document does not deprecate the mechanisms defined in [RFC3477] and [RFC4206]. Those procedures must continue to operate as described in Section 3.7. That means that the LSP_TUNNEL_INTERFACE_ID object with Class Type 1 remains unchanged, and can be used to establish an LSP that will be advertised as an unnumbered TE link in the same instance of the IGP as was used to advertise the TE links that the LSP traverses. That is, as an FA. The procedure is unchanged and operates as summarized in Section 1.3.5. Shiomoto and Farrel Expires April 2009 [Page 11] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 [RFC3477] does not make any suggestions about where in Path or Resv messages the LSP_TUNNEL_INTERFACE_ID object should be placed. See Section 3.5 for recommended placement of this object in new implementations. 3.1.2. Unnumbered Links with Action Identification A new C-Type variant of the LSP_TUNNEL_INTERFACE_ID object is defined to carry an unnumbered interface identifier and to indicate into which instance of the IGP the consequent TE link should be advertised. This does not deprecate the use of C-Type 1. The format of the object is as shown below. C-NUM = 193, C-Type = 4 (TBD by IANA) 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LSR's Router ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface ID (32 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Actions | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ LSR's Router ID Unchanged from the definition in [RFC3477]. Interface ID Unchanged from the definition in [RFC3477]. Actions This field specifies how the LSP that is being set up is to be treated. The field has meaning only on a Path message. On a Resv message the field SHOULD be set to reflect the value received on the corresponding Path message, and MUST be ignored on receipt. The field is composed of bit flags as follows: -+-+-+-+-+-+-+- | | | |H|B|R|T|P| -+-+-+-+-+-+-+- Shiomoto and Farrel Expires April 2009 [Page 12] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 P-flag (Private) 0 means that the LSP is to be advertised as a link according to the settings of the other flags. 1 means the LSP is to form a private link and is not to be advertised in the IGP, but is to be used according to the settings of the other flags. T-flag (TE link) 0 means that the LSP is to be used as a TE link. 1 means that the LSP is not to be used as a TE link. It may still be used as an IP link providing a routing adjacency as defined by the R-flag. R-flag (routing adjacency) 0 means that the link is not to be used as a routing adjacency. 1 means that the link is to be used to form a routing adjacency. B-flag (bundle) 0 means that the LSP will not form part of a link bundle. 1 means that the LSP will form part of a bundle. See Section 3.3 for more details. H-flag (hierarchy/stitching) The use of an LSP as an H-LSP or as an S-LSP is usually implicit from the network technologies of the networks and the LSP, but this is not always the case (for example, in PSC networks). 0 means LSP to be used as a hierarchical LSP. 1 means LSP to be used as a stitching segment. Other bits are reserved for future use. They MUST be set to zero on transmission and SHOULD be ignored on receipt. Note that all defined bit flags have meaning at the same time. An LSP that is to form an FA would carry the Actions field set to 0x00. That is: P=0 (advertised) T=0 (TE link) R=0 (not a routing adjacency) B=0 (not a bundle) H=0 (hierarchical LSP) Reserved The Reserved bits MUST be set to zero on transmission and SHOULD be ignored on receipt. Shiomoto and Farrel Expires April 2009 [Page 13] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 TLVs Zero, one, or more TLVs may be present. Each TLV is encoded as follows: Type (16 bits) The identifier of the TLV. Two type values are defined in this document: 1 IGP Instance Identifier TLV 2 Component Link Identifier TLV Length (16 bits) Indicates the total length of the TLV in octets. I.e., 4 + the length of the value field in octets. A value field whose length is not a multiple of four MUST be zero-padded so that the TLV is four-octet aligned. Value The data for the TLV padded as described above. If this object is carried in a Path message it is known as the "Forward Interface ID" for the LSP that is being set up. On a Resv message the object is known as the "Reverse Interface ID" for the LSP. 3.1.3. IPv4 Numbered Links with Action Identification A new C-Type variant of the LSP_TUNNEL_INTERFACE_ID object is defined to carry an IPv4 numbered interface address. The format of the object is as shown below. C-NUM = 193, C-Type = 2 (TBD by IANA) 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Interface Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Actions | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Shiomoto and Farrel Expires April 2009 [Page 14] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 IPv4 Interface Address The address assigned to the interface the sender applies to this LSP. Actions See Section 3.1.2. Reserved See Section 3.1.2. TLVs See Section 3.1.2. If this object is carried in a Path message it is known as the "Forward Interface ID" for the LSP that is being set up. On a Resv message the object is known as the "Reverse Interface ID" for the LSP. 3.1.4. IPv6 Numbered Links with Action Identification A new C-Type variant of the LSP_TUNNEL_INTERFACE_ID object is defined to carry an IPv6 numbered interface address. The format of the object is as shown below. C-NUM = 193, C-Type = 3 (TBD by IANA) 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Interface Address (128 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Interface Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Interface Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Interface Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Actions | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Shiomoto and Farrel Expires April 2009 [Page 15] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 IPv6 Interface Address The address assigned to the interface the sender applies to this LSP. Actions See Section 3.1.2. Reserved See Section 3.1.2. TLVs See Section 3.1.2. If this object is carried in a Path message it is known as the "Forward Interface ID" for the LSP that is being set up. On a Resv message the object is known as the "Reverse Interface ID" for the LSP. 3.2. Target IGP Identification TLV If the LSP being set up is to be advertised as a link, the egress needs to know which instance of the IGP it should use to make the advertisement. The default in [RFC4206] and [RFC3477] is that the LSP is advertised as an FA, that is, in the same instance of the IGP as was used to advertise the TE links that the LSP traverses. In order to facilitate an indication from the ingress to the egress of which IGP instance to use, the IGP Identification TLV is defined for inclusion in the new variants of the LSP_TUNNEL_INTERFACE_ID object defined in this document. The TLV has meaning only in a Path message. It SHOULD NOT be included in the LSP_TUNNEL_INTERFACE_ID object in a Resv message and MUST be ignored if found. If the P-flag in the Actions field of the LSP_TUNNEL_INTERFACE_ID object in a Path message is clear (i.e., zero), this TLV indicates the IGP instance to use for the advertisement. If the TLV is absent, the same instance of the IGP should be used as is used to advertise the TE links that the LSP traverses. Thus, for an FA, the TLV can be omitted; alternatively, the IGP Instance TLV may be present identifying the IGP instance or carrying the reserved value 0xffffffff. If the P-flag in the Actions field in the LSP_TUNNEL_INTERFACE_ID object in a Resv message is set (i.e., one) indicating that the LSP Shiomoto and Farrel Expires April 2009 [Page 16] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 is not to be advertised as a link, this TLV SHOULD NOT be present and MUST be ignored if encountered. The TLV is formatted as described in Section 3.1.2. The Type field has the value 1, and the Value field has the following content: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IGP Instance Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IGP Instance Identifier A 32-bit identifier be assigned to each of the IGP instances within a network, such that ingress and egress LSRs have the same understanding of these numbers. This is a management configuration exercise outside the scope of this document. Note that the IGP Instance Identifier might be mapped from an instance identifier used in the IGP itself (such as section 2.4 of [RFC5340] for OSPFv3, or [OSPFv2-MI] for OSPFv2) as a matter of network policy. See [OSPF-TI] for further discussion of this topic in OSPF, and [ISIS-GENAP] for IS-IS. The value 0xffffffff is reserved to mean that the LSP is to be advertised in the same instance of the IGP as was used to advertise the TE links that the LSP traverses. 3.3. Component Link Identification TLV If the LSP that is being set up is to be used as a component link in a link bundle [RFC4201], it is necessary to indicate both the identity of the component link and the identity of the link bundle. Furthermore, it is necessary to indicate how the link bundle (that may be automatically created by the establishment of this LSP) is to be used and advertised. If the B-flag in the Actions field of the LSP_TUNNEL_INTERFACE_ID object is set, the other fields of the object apply to the link bundle itself. That is, the interface identifiers (numbered or unnumbered) and the other flags in the Actions field apply to the link bundle and not to the component link that the LSP will form. Furthermore, the IGP Instance Identifier TLV (if present) also applies to the link bundle and not to the component link. In order to exchange the identity of the component link, the Component Link Identifier TLVs are introduced as set out in the next sections. If the B-flag is set in the Actions field of the Shiomoto and Farrel Expires April 2009 [Page 17] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 LSP_TUNNEL_INTERFACE_ID object in the Path message, exactly one of these TLVs MUST be present in the LSP_TUNNEL_INTERFACE_ID object in both the Path and Resv objects. 3.3.1. Unnumbered Component Link Identification If the component link is to be unnumbered, the Unnumbered Component Link Identifier TLV is used. The TLV is formatted as described in Section 3.1.2. The Type field has the value 2, and the Value field has the following content: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Component Link Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Component Link Identifier Unnumbered identifier that is assigned to this component link within the bundle [RFC4201]. 3.3.2. IPv4 Numbered Component Link Identification If the component link is identified with an IPv4 address, the IPv4 Numbered Component Link Identifier TLV is used. The TLV is formatted as described in Section 3.1.2. The Type field has the value 3, and the Value field has the following content: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IPv4 Address The IPv4 address that is assigned to this component link within the bundle. 3.3.2. IPv6 Numbered Component Link Identification If the component link is identified with an IPv6 address, the IPv6 Numbered Component Link Identifier TLV is used. The TLV is formatted as described in Section 3.1.2. The Type field has the value 4, and the Value field has the following content: Shiomoto and Farrel Expires April 2009 [Page 18] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Address (continued) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IPv6 Address The IPv6 address that is assigned to this component link within the bundle. 3.4. Link State Advertisement The ingress and egress of an LSP that is set up using the LSP_TUNNEL_INTERFACE_ID object MUST advertise the LSP as agreed in the parameters of the object. Where a TE link is created from the LSP, the TE link SHOULD inherit the TE properties of the LSP as described in [RFC5212] but this process is subject to local and network-wide policy. It is possible that an LSP will be used to offer capacity and connectivity to multiple other networks. In this case, multiple instances of the LSP_TUNNEL_INTERFACE_ID object are permitted in the same Path and Resv messages. Each instance MUST have a different IGP Instance Identifier. Note, however, that a Path or Resv message MUST NOT contain more than one instance of the LSP_TUNNEL_INTERFACE_ID object with C-Type 1, and if such an object is present, all other instances of the LSP_TUNNEL_INTERFACE_ID object MUST include an IGP Instance Identifier TLV with IGP Instance Identifier set to a value that identifies some other IGP instance (in particular, not the value 0xffffffff). If the link created from an LSP is advertised in the same IGP instance as was used to advertise the TE links that the LSP traverses, the addresses for the new link and that for the links it is built from MUST come from the same address space. If the link is advertised into another IGP instance the addresses MAY be drawn from overlapping address spaces such that some addresses have different meanings in each IGP instance. Shiomoto and Farrel Expires April 2009 [Page 19] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 In the IGP the TE Router ID of the ingress LSR is taken from the Tunnel Sender Address in the Sender Template object signaled in the Path message. It is assumed that the ingress LSR knows the TE Router ID of the egress LSR since it has chosen to establish an LSP to that LSR and plans to use the LSP as a TE link. The link interface addresses or link interface identifiers for the forward and reverse direction links are taken from the LSP_TUNNEL_INTREFACE_ID object on the Path and Resv messages respectively. When an LSP is torn down through explicit action (a PathTear message or a PathErr message with the Path_State_Removed flag set) the ingress and egress LSRs SHOULD withdraw the advertisement of any link that the LSP created and that was previously advertised. The link state advertisement MAY be retained as a virtual link in another layer network according to network-wide policy [PCE-LAYER]. 3.5. Message Formats [RFC3477] does not state where in the Path message or Resv message the LSP_TUNNEL_INTERFACE_ID object should be placed. It is RECOMMENDED that new implementations place the LSP_TUNNEL_INTERFACE_ID objects in the Path message immediately after the SENDER_TSPEC object, and in the Resv message immediately after the FILTER_SPEC object. All implementations SHOULD be able to handle received messages with objects in any order as described in [RFC3209]. 3.6. Error Cases and Non-Acceptance Error cases and non-acceptance of new object variants caused by back- level implementations are discussed in Section 3.7. An egress LSR that receives an LSP_TUNNEL_INTERFACE_ID object may have cause to reject the parameters carried in the object for a number of reasons as set out below. In all cases, the egress SHOULD respond with a PathErr message with the error code as indicated in the list below. In most cases the error will arise during LSP setup, no Resv state will exist, and the PathErr will cause Path state to be removed. Where the error arises after the LSP has been successfully set up, the PathErr SHOULD be sent with the Path_State_Removed flag [RFC3473] clear so that the LSP remains operational. The error cases identified are as follows and are reported using the new error code 'LSP Hierarchy Issue' (code 34 TBD by IANA) and the error values listed below. Shiomoto and Farrel Expires April 2009 [Page 20] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 Error | Error | Error-case code | value | ------+-------+------------------------------------------------------ 34 1 Link advertisement not supported 34 2 Link advertisement not allowed by policy 34 3 TE link creation not supported 34 4 TE link creation not allowed by policy 34 5 Routing adjacency creation not supported 34 6 Routing adjacency creation not allowed by policy 34 7 Bundle creation not supported 34 8 Bundle creation not allowed by policy 34 9 Hierarchical LSP not supported 34 10 LSP stitching not supported 34 11 Link address type or family not supported 34 12 IGP instance unknown 34 13 IGP instance advertisement not allowed by policy 34 14 Component link identifier not valid 34 15 Unsupported component link identifier address family When an ingress LSR receives an LSP_TUNNEL_INTERFACE_ID object on a Resv message it may need to reject it because of the setting of certain parameters in the object. Since these reasons all represent errors rather than negotiable parameter-mismatches, the ingress SHOULD respond with a PathTear to remove the LSP. The ingress MAY use a ResvErr with one of the following error codes, allowing the egress the option to correct the error in a new Resv message, or to tear the LSP with a PathErr with Path_State_Removed flag set. An ingress that uses the ResvErr MUST take precautions against a protocol loop where the egress responds with the same LSP_TUNNEL_INTERFACE_ID object with the same or different) issues. Error | Error | Error-case code | value | ------+-------+------------------------------------------------------ 34 11 Link address type or family not supported 34 14 Component link identifier not valid 34 15 Unsupported component link identifier address family 34 16 Component link identifier missing 3.7. Backward Compatibility The LSP_TUNNEL_INTERFACE_ID object defined in [RFC3477] has a class number of 193. According to [RFC2205], this means that a node that does not understand the object SHOULD ignore the object but forward it, unexamined and unmodified. Thus there are no issues with transit LSRs supporting the pre-existing or new Class Types of this object. A back-level ingress node will behave as follows: - It will not issue Path messages containing LSP_TUNNEL_INTERFACE_ID Shiomoto and Farrel Expires April 2009 [Page 21] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 objects with the new Class Types defined in this document. - It will reject Resv messages containing LSP_TUNNEL_INTERFACE_ID objects with the new Class Types defined in this document as described in [RFC2205]. In any case, such a situation would represent an error by the egress. - It will continue to use the LSP_TUNNEL_INTERFACE_ID object with Class Type 1 as defined in [RFC3477]. This behavior is supported by back-level egresses and by egresses conforming to this document. - According to an informal survey, there is no significant deployment of numbered FA establishment following the procedures defined in [RFC4206] and set out in Section 1.3.6 of this document. It is therefore safe to assume that back-level ingress LSRs will not use this mechanism. A back-level egress node will behave as follows: - It will continue to support the LSP_TUNNEL_INTERFACE_ID object with Class Type 1 as defined in [RFC3477] if issued by an ingress. - It will reject a Path message that carries an LSP_TUNNEL_INTERFACE_ID object with any of the new Class Types defined in this document using the procedures of [RFC2205]. This will inform the ingress that the egress is a back-level LSR. - It will not expect to use the procedures for numbered FA establishment defined in [RFC4206] and set out in Section 1.3.6 of this document. In summary, the new mechanisms defined in this document do not impact the method to exchange unnumbered FA information described in [RFC3477]. That mechanism can be safely used in combination with the new mechanisms described here and is functionally equivalent to using the new C-Type indicating an unnumbered link with target IGP instance identifier with the Target IGP Instance value set to 0xffffffff. The mechanisms in this document obsolete the method to exchange the numbered FA information described in [RFC4206] as described in Section 1.4.6. 4. Security Considerations [RFC3477] points out that one can argue that the use of the extra interface identifier that it provides could make an RSVP message harder to spoof. In that respect, the minor extensions to the protocol made in this document do not constitute an additional security risk, but could also be said to improve security. Shiomoto and Farrel Expires April 2009 [Page 22] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 It should be noted that the ability of an ingress LSR to request that an egress LSR advertise an LSP as a TE link MUST be subject to appropriate policy checks at the egress LSR. That is, the egress LSR MUST NOT automatically accept the word of the ingress unless it is configured with such a policy. Further details of security for MPLS-TE and GMPLS can be found in [GMPLS-SEC]. 5. IANA Considerations 5.1. New Class Types IANA maintains a registry of RSVP parameters called "Resource Reservation Protocol (RSVP) Parameters" with a sub-registry called "Class Names, Class Numbers, and Class Types." There is an entry in this registry for the LSP_TUNNEL_INTERFACE_ID object defined in [RFC3477] with one Class Type defined. IANA is requested to allocate three new Class Types for this object as defined in Sections 3.1.2, 3.1.3, and 3.1.4 as follows: C-Type Meaning Reference --------------------------------------------------------------- 2 IPv4 interface identifier with target [This.doc] 3 IPv6 interface identifier with target [This.doc] 4 Unnumbered interface with target [This.doc] 5.2. Hierarchy Actions Section 3.1.2 defines an 8-bit flags field in the LSP_TUNNEL_INTERFACE_ID object. IANA is requested to create a new sub-registry of the "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Parameters" registry called the "Hierarchy Actions" sub-registry as follows: Registry Name: Hierarchy Actions Reference: [This.doc] Registration Procedures: IETF Standards Action RFC Registry: Bit Number Hex Value Name Reference ---------- ----------- ----------------------- --------- 0-2 Unassigned 3 0x10 Hierarchy/stitching (H) [This.doc] 4 0x08 Bundle (B) [This.doc] 5 0x04 Routing adjacency(R) [This.doc] 6 0x02 TE link (T) [This.doc] 7 0x01 Private (P) [This.doc] Shiomoto and Farrel Expires April 2009 [Page 23] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 5.3. New Error Codes and Error Values IANA maintains a registry of RSVP error codes and error values as the "Error Codes and Globally-Defined Error Value Sub-Codes" sub-registry of the "Resource Reservation Protocol (RSVP) Parameters" registry. IANA is requested to define a new error code with suggested value 34 as below (see also Section 3.6). Error Code Meaning 34 LSP Hierarchy Issue [This.doc] IANA is requested to list the following error values for this error code (see also Section 3.6). This Error Code has the following globally-defined Error Value sub-codes: 1 = Link advertisement not supported [This.doc] 2 = Link advertisement not allowed by policy [This.doc] 3 = TE link creation not supported [This.doc] 4 = TE link creation not allowed by policy [This.doc] 5 = Routing adjacency creation not supported [This.doc] 6 = Routing adjacency creation not allowed by policy [This.doc] 7 = Bundle creation not supported [This.doc] 8 = Bundle creation not allowed by policy [This.doc] 9 = Hierarchical LSP not supported [This.doc] 10 = LSP stitching not supported [This.doc] 11 = Link address type or family not supported [This.doc] 12 = IGP instance unknown [This.doc] 13 = IGP instance advertisement not allowed by policy [This.doc] 14 = Component link identifier not valid [This.doc] 15 = Unsupported component link identifier address [This.doc] family 16 = Component link identifier missing [This.doc] 6. Acknowledgements The authors would like to thank John Drake, Yakov Rekhter, and Igor Bryskin for their valuable discussions and comments. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Shiomoto and Farrel Expires April 2009 [Page 24] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 [RFC2205] Braden, R., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC3031] Rosen, E., Viswanathan, A. and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [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. [RFC3473] Berger, L., Editor, "Generalized Multi-Protocol Label Switching (MPLS) Signaling Resource ReserVation Protocol Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3477] Kompella, K. and Rekhter, Y., "Signalling Unnumbered Links in Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE)", RFC 3477, January 2003. [RFC4201] Kompella, K., Rekhter, Y., and Berger, L.," Link Bundling in MPLS Traffic Engineering (TE)", RFC 4201, October 2005. [RFC4206] Kompella, K. and Y. Rekhter, "LSP Hierarchy with Generalized MPLS TE", RFC 4206, October 2005. [RFC5150] Ayyangar, A., Vasseur, J.P, and Farrel, A., "Label Switched Path Stitching with Generalized Multiprotocol Label Switching Traffic Engineering (GMPLS TE)", RFC 5150, February 2008. 7.2. Informative References [RFC1195] Callon, R.W., "Use of OSI IS-IS for routing in TCP/IP and dual environments", RFC 1195, December 1990 [RFC1256] Deering, S., "ICMP Router Discovery Messages", RFC 1256, September 1991. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC3630] Katz, D., Kompella, K. and Yeung, D., "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, September 2003. [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, October 2005. Shiomoto and Farrel Expires April 2009 [Page 25] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 [RFC4203] Kompella, K. Ed. and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005. [RFC5212] Shiomoto, K., et al, "Requirements for GMPLS-Based Multi- Region and Multi-Layer Networks (MRN/MLN)", RFC 5212, July 2008 [RFC5305] Smit, H. and T. Li, "Intermediate System to Intermediate System (IS-IS) Extensions for Traffic Engineering (TE)", RFC 5305, October 2008. [RFC5307] Kompella, K. Ed. and Y. Rekhter, Ed., "Intermediate System to Intermediate System (IS-IS) Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 5307, October 2008. [RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308, October 2008. [RFC5329] Ishiguro, K., Manral, V., Davey, A., and Lindem, A., (Ed.), "Traffic Engineering Extensions to OSPF version 3", RFC 5329, September 2008. [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, July 2008. [GMPLS-SEC] Fang, L., et al., "Security Framework for MPLS and GMPLS Networks", draft-ietf-mpls-mpls-and-gmpls-security- framework, work in progress. [ISIS-GENAP] Ginsberg, L., Previdi, S., and Shand, M., "Advertising Generic Information in IS-IS", draft-ietf-isis-genapp, work in progress. [ISIS-IPV6-TE] Harrison, J., Berger, J., and Bartlett, M., "IPv6 Traffic Engineering in IS-IS", draft-ietf-isis-ipv6-te, work in progress. [OSPF-TI] Lindem, A., Roy, A., and Mirtorabi, S., "OSPF Transport Instance Extensions", draft-acee-ospf-transport-instance, work in progress. [OSPFv2-MI] Lindem, A., Roy, A., and Mirtorabi, S., "OSPF Multi- Instance Extensions", draft-acee-ospf-multi-instance, work in progress. [PCE-LAYER] Oki, E. (Ed.), "PCC-PCE Communication and PCE Discovery Requirements for Inter-Layer Traffic Engineering", draft- ietf-pce-inter-layer-req, (work in progress). Shiomoto and Farrel Expires April 2009 [Page 26] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 8. Editors' Addresses Kohei Shiomoto NTT Network Service Systems Laboratories 3-9-11 Midori Musashino, Tokyo 180-8585 Japan Phone: +81 422 59 4402 Email: shiomoto.kohei@lab.ntt.co.jp Adrian Farrel Old Dog Consulting EMail: adrian@olddog.co.uk 9. Authors' Addresses Richard Rabbat Google Inc. 1600 Amphitheatre Pkwy Mountain View, CA 94043 Email: rabbat@alum.mit.edu Arthi Ayyangar Juniper Networks 1194 N. Mathilda Ave. Sunnyvale, CA 94089 United States of America Email: arthi@juniper.net Zafar Ali Cisco Systems, Inc. 2000 Innovation Drive Kanata, Ontario, K2K 3E8 Canada. EMail: zali@cisco.com 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 Shiomoto and Farrel Expires April 2009 [Page 27] Internet-Draft draft-ietf-ccamp-lsp-hierarchy-bis-04 October 2008 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. Copyright Statement Copyright (C) The IETF Trust (2008). 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. 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. Shiomoto and Farrel Expires April 2009 [Page 28]