CCAMP Working Group Zafar Ali, Ed. Internet Draft George Swallow, Ed. Intended status: Standard Track Cisco Systems Expires: January 3, 2015 F. Zhang, Ed. Huawei D. Beller, Ed. Alcatel-Lucent July 4, 2014 Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Path Diversity using Exclude Route draft-ietf-ccamp-lsp-diversity-04.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." 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Ali, Swallow, Zhang, Beller, et al Expires January 2015 [Page 1] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Abstract RFC 4874 specifies methods by which path exclusions may be communicated during RSVP-TE signaling in networks where precise explicit paths are not computed by the LSP source node. This document specifies procedures for additional route exclusion subobject based on Paths currently existing or expected to exist within the network. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Table of Contents 1. Introduction ............................................... 2 1.1. Client Initiated Identifier ........................ 5 1.2. PCE allocated Identifiers .......................... 6 1.3. UNI-N allocated Identifiers ........................ 7 2. RSVP-TE signaling extensions ............................... 9 2.1. Diversity XRO Subobject ............................ 9 2.1.1. Tunnel identifier TLVs ........................... 12 2.1.2. Path Key TLVs .................................... 14 2.1.3. Path Affinity Set TLVs ........................... 16 2.2. Processing rules for the Diversity XRO subobject ... 19 2.2.1. Processing rules for the tunnel identifier TLVs .. 20 2.2.2. Processing rules for the Path Key TLVs ........... 22 2.2.3. Processing rules for the PAS TLVs ................ 23 2.3. Diversity EXRS Subobject ........................... 25 3. Security Considerations .................................... 27 4. IANA Considerations ........................................ 27 6. References ................................................. 28 6.1. Normative References ............................... 28 6.2. Informative References ............................. 29 1. Introduction Path diversity for multiple connections is a well-known Service Provider requirement. Diversity constraints ensure that Label- Switched Paths (LSPs) may be established without sharing Expires January 2015 [Page 2] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt resources, thus greatly reducing the probability of simultaneous connection failures. When a source node has full topological knowledge and is permitted to signal an Explicit Route Object (ERO), diverse paths can be computed locally. However, there are scenarios when path computations are performed by remote nodes, thus there is a need for relevant diversity constraints to be communicated to those nodes. These include (but are not limited to): . LSPs with loose hops in the ERO, e.g. inter-domain LSPs; . Generalized Multi-Protocol Label Switching (GMPLS) User- Network Interface (UNI) where path computation may be performed by the core node [RFC4208]. [RFC4874] introduced a means of specifying nodes and resources to be excluded from a route, using the eXclude Route Object (XRO) and Explicit Exclusion Route Subobject (EXRS). It facilitates the calculation of diverse paths for LSPs based on known properties of those paths including addresses of links and nodes traversed, and Shared Risk Link Groups (SRLGs) of traversed links. Employing these mechanisms requires that the source node that initiates signaling knows the relevant properties of the path(s) from which diversity is desired. However, there are circumstances under which this may not be possible or desirable, including (but not limited to): . Exclusion of a path which does not originate, terminate or traverse the source node signaling the diverse LSP, in which case the addresses and SRLGs of the path from which diversity is required are unknown to the source node. . Exclusion of a path which is known to the source node of the diverse LSP, however the node has incomplete or no path information, e.g. due to policy. In other words, the scenario in which the reference path is known by the source / requesting node but the properties required to construct an XRO object are not fully known. Inter-domain and GMPLS overlay networks can present such restrictions. This is exemplified in the Figure 1, where overlay reference model from [RFC4208] is shown. Expires January 2015 [Page 3] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Overlay Overlay Network +----------------------------------+ Network +---------+ | | +---------+ | +----+ | | +-----+ +-----+ +-----+ | | +----+ | | | | | UNI | | | | | | | | UNI | | | | | -+ EN1+-+-----+--+ CN1 +----+ CN2 +----+ CN3 +---+-----+-+ EN3+- | | | | | +--+--+ | | | | | | +---+-| | | | +----+ | | | +--+--+ +--+--+ +--+--+ | | | +----+ | +---------+ | | | | | | | +---------+ | | | | | | | +---------+ | | +--+--+ | +--+--+ | | +---------+ | +----+ | | | | | +-------+ +-----+ | +----+ | | | +-+--+ | | CN4 +---------------+ CN5 | | | | | | | -+ EN2+-+-----+--+ | | +---+-----+-+ EN4+- | | | | | UNI | +-----+ +-----+ | UNI | | | | | +----+ | | | | +----+ | +---------+ +----------------------------------+ +---------+ Overlay Core Network Overlay Network Network Legend: EN - Edge Node CN - Core Node Figure 1: Overlay Reference Model [RFC4208] Figure 1 depicts two types of UNI connectivity: single-homed and dual-homed ENs (which also applies to higher order multi-homed connectivity.). Single-homed Edge Node (EN) devices are connected to a single Core Node (CN) device via a single UNI link. This single UNI link may constitute a single point of failure. UNI connection between EN1 and CN1 is an example of singled-homed UNI connectivity. A single point of failure caused by a single-homed UNI can be avoided when the EN device is connected to two different CN devices, as depicted for EN2 in Figure 1. For the dual-homing case, it is possible to establish two different UNI connections from the same source EN device to the same destination EN device. For example, two connections from EN2 to EN3 may use the two UNI links EN2-CN1 and EN2-CN4. To avoid single points of failure within the provider network, it is necessary to also ensure path (LSP) diversity within the core network. In Figure 1, the CNs typically performs path computation. Information sharing across the UNI boundary is restricted based on the policy rules imposed by the core network. Typically, the Expires January 2015 [Page 4] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt core network topology information is not exposed to the ENs. In such networks, consider a use case where an LSP from EN2 to EN4 needs to be SRLG diverse from an LSP from EN1 to EN3. In this case, EN2 may not know SRLG attributes of the EN1- EN3 LSP and hence cannot construct an XRO to exclude these SRLGs. In this example EN2 cannot use procedures described in [RFC4874]. Similarly, in the context of dual-homed UNI example described above, an LSP from EN2 to EN3 going via CN1 needs to be diverse from an LSP from EN2 to EN3 going via CN4. Again in this case, [RFC4874] based exclusions cannot be used. This document addresses these diversity requirements by introducing the notion of excluding the path taken by particular LSP(s). The reference LSP(s) with which diversity is required is identified by an "identifier". The type of identifier to use is highly dependent on the networking deployment scenario. For example, if the identifier is client initiated, the network allocates identifier or a Path Computation Element (PCE) manages identifier. Consequently, this document defines three different types of identifiers: client initiated identifier, PCE allocated Identifier and network allocated Identifier, as detailed in the following sections. 1.1. Client Initiated Identifier There are scenarios in which the ENs have the following requirements for the diversity identifier: - The identifier is controller by the client side and is specified as part of the service request. - Both client and server should understand the identifier. - The identifier needs to be reference able even if the LSP referenced by it is not yet signaled. - The identifier should be stable for a long period of time. - The identifier should be stable even when the tunnel is rerouted. - The identifier should be human readable. The above-mentioned requirements are met by using RSVP tunnel/ LSP Forwarding Equivalence Class (FEC) as the identifier. Consequently, RSVP tunnel/ LSP FEC is used as client initiated identifier. Expires January 2015 [Page 5] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt The usage of the client-initiated identifier is illustrated by using Figure 1. Suppose a tunnel from EN2 to EN4 needs to be diverse with respect to a tunnel from EN1 to EN3. Lets assume tunnel FEC of the EN1-EN3 tunnel is FEC1, where FEC1 is defined by the tuple (tunnel-id = T1, source address = EN1.ROUTE Identifier (RID), destination address = EN3.RID, extended tunnel- id = EN1.RID). Similarly, tunnel FEC of the EN2-EN3 tunnel is FEC2, where FEC2 is defined by the tuple (tunnel-id = T2, source address = EN2.RID, destination address = EN4.RID, extended tunnel-id = EN2.RID). EN1-EN3 tunnel is signaled such that it specifies the exclusion requirement from FEC2. Similarly, EN2-EN3 tunnel is signaled such that it specifies the exclusion requirement from FEC1. In order to maintain diversity between these two connections within the core network, it is assumed that the core network implements Crank back Signaling [RFC4920]. Similarly, diversity within the core network for a dual homed UNI case is satisfied by the use of Crank back Signaling [RFC4920]. 1.2. PCE allocated Identifiers In scenarios where a PCE is deployed and used to perform path computation, the core edge node (e.g., node CN1 in Figure 1) could consult a PCE to allocate identifiers, which are used to signal path diversity constraints. In other scenarios a PCE is deployed in each border node or a PCE is part of the Network Management System (NMS). In all these cases, the Path key as defined in [RFC5520] can be used in RSVP signaling as the identifier to ensure diversity. The usage of specifying LSP diversity using Path Key is exemplified in Figure 2, where a simple network with two domains is shown. It is desired to set up a pair of path-disjoint LSPs from the source in Domain 1 to the destination in Domain 2, but the domains keep strict confidentiality about all path and topology information. The first LSP is signaled by the source with ERO {A, B, loose Dst} and is set up with the path {Src, A, B, U, V, W, Dst}. However, when sending the RRO out of Domain 2, node U would normally strip the path and replace it with a loose hop to the destination. With this limited information, the source is unable to include enough detail in the ERO of the second LSP to avoid it taking, for example, the path {Src, C, D, X, V, W, Dst} for path-disjointness. Expires January 2015 [Page 6] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt --------------------- ----------------------------- | Domain 1 | | Domain 2 | | | | | | --- --- | | --- --- --- | | | A |--| B |--+--+--| U |--| V |---| W | | | / --- --- | | --- --- --- \ | | ---/ | | / / \--- | | |Src| | | / / |Dst| | | ---\ | | / / /--- | | \ --- --- | | --- / --- / --- / | | | C |--| D |--+--+--| X |---| Y |--| Z | | | --- --- | | --- --- --- | | | | | --------------------- ----------------------------- Figure 2: A Simple Multi-Domain Network In order to improve the situation, node U performs the PCE function and replaces the path segment {U, V, W} in the RRO with a Path Key Subobject [RFC5553]. The Path Key Subobject assigns an "identifier" to the key. The PCE ID in the message indicates that it was node U that made the replacement. With this additional information, the source is able to signal the subsequent LSPs with the ERO set to {C, D, exclude Path Key(EXRS), loose Dst}. When the signaling message reaches node X, it can consult node U to expand the Path Key and know how to avoid the path of the first LSP. Alternatively, the source could use an ERO of {C, D, loose Dst} and include an XRO containing the Path Key. 1.3. Network allocated Identifiers There are scenarios in which the network provides diversity information for a service that allows the client device to include this information in the signaling message. In this section two signaling approaches are outlined that use network allocated identifiers. While both methods could be implemented in the same core network, it is very likely that a core network supports only one of the two mechanisms. The first method assumes that core network Shared Resource Link Group (SRLG) identifier information is both available and shareable (by policy) with the ENs. In this case, the procedure defined in [DRAFT-SRLG-RECORDING] can be used to collect SRLG identifiers associated with an LSP (say LSP1). Suppose that LSP2 Expires January 2015 [Page 7] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt needs to be diverse with respect to LSP1. When the EN constructs the RSVP signaling message for setting up LSP2, it can insert the SRLG identifiers associated with LSP1 as diversity constraints into the XRO using the procedure described in [RFC4874]. This method is not discussed further as it utilizes existing RSVP protocol mechanisms for collecting SRLG information and passing this diversity information to the CN. The second method assumes that core network SRLG identifiers are either not available or not shareable with the ENs based on policies enforced by core network. In this case, a signaling mechanism is defined where information signaled to the CN via the UNI does not require shared knowledge of provider SRLG information. For this purpose, notion of Path Affinity Set (PAS) is used for abstracting SRLG information. The motive behind the PAS information is to have as little exchange of diversity information as possible between the core network (CNs) and the client devices (ENs). I.e., rather than a detailed SRLG list, the PAS contains an abstract SRLG identifier associated with a given path. There are two types of diversity information in the PAS. The first type of information is a single PAS identifier. The Second part is the optional PATH information, in the form of Source and Destination addresses of a path. This mechanism can also be applied to L1 VPNs and in this particular case, the identifier only needs to be unique within the scope of a particular VPN. A CN on the core network boundary interprets the specific PAS identifier, for example, "123" as meaning to exclude the core network SRLG information (or equivalent) that has been allocated by LSPs associated with this PAS identifier value. For example, if a Path exists for the LSP with the identifier "123", the CN would use local knowledge of the core network SRLGs associated with the "123" LSPs and use those SRLGs as constraints for path computation. In other words, two LSPs that need to be diverse both signal "123" and the CNs interpret this as meaning not to use shared resources. Alternatively, a CN could use the PAS identifier to select from already established LSPs. Once the path is established core network allocated the "123" identifier or optionally another PAS identifier for that VPN that replaces "123". The optional PAS source and destination address tuple represents one or more source addresses and destination addresses associated with the EN PAS identifier. These associated address tuples represent paths that use resources that should be excluded for Expires January 2015 [Page 8] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt the establishment of the current LSP. The address tuple information gives both finer grain details on the path diversity request and serves as an alternative identifier in the case when the PAS identifier is not known by the CN. The address tuples used in signaling is within a client network context and its interpretation is local to a CN that receives a Path request from an EN. The CN can use the address information to relate to CN addresses and core network SRLG information. When a CN satisfies a connection setup for a (SRLG) diverse signaled path, the CN may optionally record the core network SRLG information for that connection in terms of CN based parameters and associates that with the EN addresses in the Path message. Specifically for L1VPNs, Port Information tables (PIT) [RFC5251] can be leveraged to translate between client (EN) based addresses and core network based addresses. The PAS and associated core network addresses with core network SRLG information can be distributed via the IGP in the core network (or by other means such as configuration); they can be utilized by other CNs when other ENs are requesting paths to be setup that would require path/connection diversity. In the VPN case, this information is distributed on a VPN basis and contains a PAS identifier, CN addresses and SRLG information. If diversity is not signaled, the assumption is that no diversity is required and the core network is free to route the LSP to optimize traffic. No Path affinity set information needs to be recorded for these LSPs. If a diversity object is included in the connection request, the CN in the core network should be able to determine (look-up) the existing core network SRLG information and choose an LSP that is maximally diverse from other LSPs. The Path Affinity Set identifier is independent of the mechanism the EN or the CN use for diversity. The Path Affinity Set is a single identifier that can be used to request diversity and associate diversity. 2. RSVP-TE signaling extensions This section describes the signaling extensions required to address the aforementioned requirements and use cases. 2.1. Diversity XRO Subobject New Diversity XRO subobjects are defined by this document as follows. Expires January 2015 [Page 9] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type |Attribute Flags|Exclusion Flags| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLVs ... | // // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ L: The L-flag is used as for the XRO subobjects defined in [RFC4874], i.e., 0 indicates that the attribute specified MUST be excluded. 1 indicates that the attribute specified SHOULD be avoided. Type Type for diversity XRO subobject (to be assigned by IANA; suggested value: 37). Attribute Flags: The Attribute Flags are used to communicate desirable attributes of the LSP being signaled. The following flags are defined. Each flag acts independently. Any combination of flags is permitted. 0x01 = Destination node exception Indicates that exclusion does not apply to the destination node of the LSP being signaled. 0x02 = Processing node exception Indicates that exclusion does not apply to the border node(s) performing ERO expansion for the LSP being signaled. Ingress UNI-N node is an example of such nodes. 0x04 = Penultimate node exception Expires January 2015 [Page 10] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Indicates that the penultimate node of the LSP being signaled MAY be shared with the excluded path even when this violates the exclusion flags. 0x08 = LSP ID to be ignored This flag is only applicable to the IPv4/ IPv6 Point-to- Point tunnel identifier TLVs of the Diversity XRO subobjects defined in section 2.1.1. In this context, the flag indicates tunnel level exclusion. Specifically, this flag is used to indicate that the lsp-id field of the IPv4/ IPv6 Point-to-Point tunnel identifier TLVs is to be ignored and the exclusion applies to any LSP matching the rest of the supplied FEC. Exclusion Flags The Exclusion-Flags are used to communicate the desired type(s) of exclusion. The following flags are defined. 0x01 = SRLG exclusion Indicates that the path of the LSP being signaled is requested to be SRLG diverse from the excluded path specified by the Diversity subobject. 0x02 = Node exclusion Indicates that the path of the LSP being signaled is requested to be node diverse from the excluded path specified by the Diversity subobject. (Note: the meaning of this flag may be modified by the value of the Attribute-flags.) 0x04 = Link exclusion Indicates that the path of the LSP being signaled is requested to be link diverse from the path specified by the Diversity subobject. Expires January 2015 [Page 11] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt TLVs (Type-Length-Value tuples) have the following format. Only one TLV is allowed in the Diversity XRO subobject. However, multiple Diversity XRO subobjects may be present in an XRO. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value | // // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Types (2 bytes): This document defines the following types of TLVs: - Type = 1: IPv4 Point-to-Point tunnel identifier. - Type = 2: IPv6 Point-to-Point tunnel identifier. - Type = 3: IPv4 Path Key. - Type = 4: IPv6 Path Key. - Type = 5: IPv4 Path Affinity Set (PAS). - Type = 6: IPv6 Path Affinity Set (PAS). Format of the individual TLVs is described in the following. 2.1.1. Tunnel identifier TLVs The IPv4 and IPv6 Point-to-Point (P2P) tunnel identifier TLVs for diversity XRO subobjects are defined as follows. 2.1.1.1. IPv4 Point-to-Point tunnel identifier TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 1 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 tunnel end point address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires January 2015 [Page 12] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt | Must Be Zero | Tunnel ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 tunnel sender address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv4 Point-to-Point tunnel identifier TLV (to be assigned by IANA; suggested value: 1). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 24. The remaining fields are as defined in [RFC3209]. Please note that the L-bit, exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv4 Point-to-Point tunnel identifier TLV. 2.1.1.2. IPv6 Point-to-Point tunnel identifier TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 2 | Length = 60 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel end point address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel end point address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel end point address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel end point address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | Tunnel ID | Expires January 2015 [Page 13] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel sender address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel sender address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel sender address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel sender address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv6 Point-to-Point tunnel identifier TLV (to be assigned by IANA; suggested value: 2). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 60. The remaining fields are as defined in [RFC3209]. Please note that the L-bit, exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv6 Point-to-Point tunnel identifier TLV. 2.1.2. Path Key TLVs The IPv4 and IPv6 Path Key TLVs for diversity XRO subobjects are defined as follows. Expires January 2015 [Page 14] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt 2.1.2.1. IPv4 Path Key TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 3 | Length = 12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | Path Key | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PCE ID (4 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv4 Path Key TLV (to be assigned by IANA; suggested value: 3). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 12. Path Key: Path Key is defined in [RFC5553]. PCE-ID: The IPv4 address of a node that assigned the Path Key identifier and that can return an expansion of the Path Key or use the Path Key as exclusion in a path computation. Please note that exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv4 Path Key TLV. 2.1.2.2. IPv6 Path Key TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 4 | Length = 24 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires January 2015 [Page 15] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt | Must Be Zero | Path Key | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PCE ID (16 bytes) | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv4 Path Key TLV (to be assigned by IANA; suggested value: 4). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 24. Path Key: Path Key is defined in [RFC5553]. PCE-ID: The IPv6 address of a node that assigned the Path Key identifier and that can return an expansion of the Path Key or use the Path Key as exclusion in a path computation. Please note that the L-bit, exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv6 Path Key TLV. 2.1.3. Path Affinity Set TLVs The IPv4 and IPv6 Path Affinity Set (PAS) TLVs for diversity XRO subobjects are defined as follows. 2.1.3.1. IPv4 PAS TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires January 2015 [Page 16] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt | Type = 5 | Length = 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Path Affinity Set identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Path Source Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Path Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv4 PAS TLV (to be assigned by IANA; suggested value: 5). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 16. Path Affinity Set identifier: The Path affinity Set identifier (4 bytes) is a single number that represents a summarized SRLG for this path. IPv4 Path Source Address: The IPv4 address of the source node associated with the Path. IPv4 Path Destination Address: The IPv4 address of the destination node associated with the Path. Please note that L-bit, exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv4 PAS TLV. 2.1.3.2. IPv6 PAS TLV 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 Expires January 2015 [Page 17] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 6 | Length = 40 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Path Affinity Set identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Source Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Source Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Source Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Source Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Destination Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Destination Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 Path Destination Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: IPv6 PAS TLV (to be assigned by IANA; suggested value: 6). Length: The length contains the total length of the TLV in bytes, including the type and length fields. The length is always 40. Path Affinity Set identifier: The Path affinity Set identifier (4 bytes) is a single number that represents a summarized SRLG for this path. IPv6 Path Source Address: The IPv6 address of the source node associated with the Path. IPv6 Path Destination Address: Expires January 2015 [Page 18] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt The IPv6 address of the destination node associated with the Path. Please note that the L-bit, exclusion and attribute flags defined at the diversity XRO subobject level in Section 2.1 are equally applicable to the IPv6 PAS TLV. 2.2. Processing rules for the Diversity XRO subobject The procedure defined in [RFC4874] for processing XRO and EXRS is not changed by this document. If the processing node cannot recognize the Diversity XRO subobject or the TLV contained in it, the node follows procedure defined in [RFC4874]. An XRO object MAY contain multiple Diversity subobjects. However, all Diversity subobjects are expected to contain the same TLV type. If a Path message contains an XRO with Diversity subobjects with TLVs of different types, the processing node SHOULD return a PathErr with the error code "Routing Problem" (24) and error sub- code "XRO Too Complex" (68). If the processing node is the destination for the LSP being signaled, it SHOULD NOT process a Diversity XRO subobject. The attribute-flags affect the processing of the Diversity XRO subobject as follows: o When the "destination node exception" flag is not set, the exclusion flags SHOULD also be respected for the destination node. o When the "processing node exception" flag is not set, the exclusion flags SHOULD also be respected for the processing node. o When the "penultimate node exception" flag is not set, the exclusion flags SHOULD also be respected for the penultimate node. o The use of "LSP ID to be ignored" flag is only defined for the IPv4 and IPv6 tunnel identifier TLVs. This flag is never set and is always ignored in processing all other TLVs. When the "LSP ID to be ignored" flag is set, the processing node MUST calculate a path based on exclusions Expires January 2015 [Page 19] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt from the paths of all known LSPs matching the tunnel-id, source, destination and extended tunnel-id specified in the subobject (i.e., tunnel level exclusion). When this flag is not set, the lsp-id is not ignored and the exclusion applies only to the specified LSP (i.e., LSP level exclusion). The rest of the processing role depends on the TLV carried by the object. 2.2.1. Processing rules for the tunnel identifier TLVs This section describes processing rules for the IPv4 and IPv6 tunnel identifier TLVs. If the L-flag of the diversity XRO subobject is not set, the processing node follows the following procedure: - The processing node MUST ensure that any path calculated for the signaled LSP respects the requested exclusion flags with respect to the excluded path referenced by the subobject, including local resources. - If the processing node fails to find a path that meets the requested constraint, the processing node MUST return a PathErr with the error code "Routing Problem" (24) and error sub-code "Route blocked by Exclude Route" (67). - If the excluded path referenced in the tunnel identifier TLV is unknown to the processing node, the processing node SHOULD ignore the tunnel identifier TLV in the diversity XRO subobject of XRO and SHOULD proceed with the signaling request. After sending the Resv for the signaled LSP, the processing node SHOULD return a PathErr with the error code "Notify Error" (25) and error sub-code "Route of XRO tunnel identifier unknown" (value to be assigned by IANA, suggested value: 13) for the signaled LSP. If the L-flag of the diversity XRO subobject is set, the processing node follows the procedure below: - The processing node SHOULD respect the requested exclusion flags with respect to the excluded path to the extent possible. - If the processing node fails to find a path that meets the requested constraint, it SHOULD proceed with signaling using a suitable path that meets the constraint as far as possible. Expires January 2015 [Page 20] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt After sending the Resv for the signaled LSP, it SHOULD return a PathErr message with error code "Notify Error" (25) and error sub-code "Failed to respect Exclude Route" (value: to be assigned by IANA, suggest value: 14) to the source node. - If the excluded path referenced in the tunnel identifier TLV is unknown to the processing node, the processing node SHOULD ignore the tunnel identifier TLV in the diversity XRO subobject of XRO and SHOULD proceed with the signaling request. After sending the Resv for signaled LSP, the processing node SHOULD return a PathErr message with the error code "Notify Error" (25) and error sub-code "Route of XRO tunnel identifier unknown" for the signaled LSP. If, subsequent to the initial signaling of a diverse LSP: - An excluded path referenced in the diverse LSP's XRO tunnel identifier becomes known to the processing node (e.g. when the excluded path is signaled), or - A change in the excluded path becomes known to the processing node, the processing node SHOULD re-evaluate the exclusion and diversity constraints requested by the diverse LSP to determine whether they are still satisfied. - If the requested exclusion constraints for the diverse LSP are no longer satisfied and an alternative path for the diverse LSP that can satisfy those constraints exists, the processing node SHOULD send a PathErr message for the diverse LSP with the error code "Notify Error" (25) and a new error sub-code "compliant path exists" (value: to be assigned by IANA, suggest value: 15). A source node receiving a PathErr message with this error code and sub-code combination MAY try to reoptimize the diverse tunnel to the new compliant path. - If the requested exclusion constraints for the diverse LSP are no longer satisfied and no alternative path for the diverse LSP that can satisfy those constraints exists, then: o If the L-flag was not set in the original exclusion, the processing node MUST send a PathErr message for the diverse LSP with the error code "Routing Problem" (24) and error sub-code "Route blocked by Exclude Route" (67). The PSR flag SHOULD NOT be set. o If the L-flag was set in the original exclusion, the processing node SHOULD send a PathErr message for the Expires January 2015 [Page 21] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt diverse LSP with the error code error code "Notify Error" (25) and error sub-code "Failed to respect Exclude Route" (value: to be assigned by IANA, suggest value: 14). The following rules apply whether or not the L-flag is set: - A source node receiving a PathErr message with the error code "Notify Error" (25) and error sub-codes "Route of XRO tunnel identifier unknown" or "Failed to respect Exclude Route" MAY take no action. 2.2.2. Processing rules for the Path Key TLVs This section describes processing rules for the IPv4 and IPv6 Path Key TLVs. An EN may include a path-key identifier (PKS) in the path-key TLVs of the diversity XRO subobject to convey diversity constraints. In order to exclude multiple PKS, an EN may include multiple diversity XRO subobjects each with a different path-key. If the node, receiving the path-key TLV, cannot recognize the subobject, it will react according to [RFC4874] and SHOULD ignore the constraint. Otherwise, if it decodes the path-key TLV but cannot find a route/route segment meeting the constraint: -if L flag is set to 0, it will react according to [RFC4874] and SHOULD send a PathErr message with the error code "Routing Problem" (24) and the error sub-code "Route blocked by Exclude Route" (67). -if L flag is set to 1, which means the node SHOULD try to be as much diversified as possible with the specified resource. If it cannot fully support the constraint, it SHOULD send a PathErr message with the error code/value combination "Notify Error" / "Failed to respect Exclude Route" (value: to be assigned by IANA, suggest value: 14). The following rules apply whether or not the L-flag is set: - A source node receiving a PathErr message with the error code "Notify Error" (25) and error sub-codes "Failed to respect Exclude Route" MAY take no action. This mechanism can work with all the PKS resolution mechanisms, as detailed in [RFC5553] section 3.1. A PCE, co-located or not, may be used to resolve the PKS, but the node (i.e., a Label Expires January 2015 [Page 22] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Switcher Router (LSR)) can also use the PKS information to index a Path Segment previously supplied to it by the entity that originated the PKS, for example the LSR that inserted the PKS in the RRO or a management system. 2.2.3. Processing rules for the PAS TLVs This section describes processing rules for the IPv4 and IPv6 PAS TLVs. An EN may include a PAS identifier in the PAS TLVs of the diversity XRO subobject to convey diversity constraints. In order to exclude multiple PAS identifiers, an EN may include multiple diversity XRO subobjects each with a different PAS identifier. How an EN determines the PAS identifier is a local matter for the EN administrator. This identifier is a suggested identifier and may be overridden by a CN under some conditions, regardless if L bit is set or not. For example, a PAS identifier can be used with no prior exchange of PAS information between the EN and the CN. Upon reception of the PAS identifier information the CN can infer the EN's requirements. The actual PAS identifier used will be returned in the RESV message. If the L-flag of the diversity XRO subobject is not set, the processing node follows the following procedure: - The processing node MUST ensure that any path calculated for the signaled LSP respects the requested PAS exclusion, including local resources. - If the processing node fails to find a path that meets the requested constraint, the processing node MUST return a PathErr with the error code "Routing Problem" (24) and error sub-code "Route blocked by Exclude Route" (67). - If the PAS value referenced in the PAS TLV is unknown to the processing node, the processing node MAY infer the diversity requirement. After sending the Resv for the signaled LSP, the processing node SHOULD return a PathErr with the error code "Notify Error" (25) and error sub-code "XRO PAS value inferred" (value to be assigned by IANA, suggested value: TBD). However, if processing node fails to infer the diversity requirement from PAS value, it MUST return a PathErr with the error code "Routing Problem" (24) and error sub-code "Route blocked by Exclude Route" (67). Expires January 2015 [Page 23] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt If the L-flag of the diversity XRO subobject is set, the processing node follows the procedure below: - The processing node SHOULD ensure that any path calculated for the signaled LSP respects the requested PAS exclusion, including local resources. - If the processing node fails to find a path that meets the requested constraint, it SHOULD proceed with signaling using a suitable path that meets the constraint as far as possible. After sending the Resv for the signaled LSP, it SHOULD return a PathErr message with error code "Notify Error" (25) and error sub-code "Failed to respect Exclude Route" (value: to be assigned by IANA, suggest value: 14) to the source node. - If the PAS value referenced in the PAS TLV is unknown to the processing node, the processing node MAY infer the diversity requirement. However, if processing node fails to infer the diversity requirement it MAY ignore the PAS TLV in the diversity XRO subobject of XRO and SHOULD proceed with the signaling request. After sending the Resv for signaled LSP, the processing node SHOULD return a PathErr message with the error code "Notify Error" (25) and error sub-code "Failed to respect Exclude Route" (value: to be assigned by IANA, suggest value: 14) to the source node. In the context of VPN, upon reception of the PAS identifier information, the CN looks up the CN based addresses in the Provider Index Table (PIT). The CN also looks up the SRLG information (or equivalent) in the core network that is associated with LSPs belonging to the same Path Affinity Set and exclude those resources from the path computation for this LSP. The CN may alternatively choose from an existing path with a disjoint set of resources. Optionally the EN may use a value of all zeros in the PAS identifier allowing the CN to select an appropriate PAS identifier. Also the CN may to override the PAS identifier allowing the CN to re-assign the identifier if required. An EN should not assume that the PAS identifier used for setup is the actual PAS identifier. Expires January 2015 [Page 24] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt 2.2.3.1.1. Distribution of the Path Affinity Set Information Information about TE link SRLGs is already available in the IGP TE database. A core network can be designed to have additional opaque records for core network paths that distribute EN paths, PAS values associated with them and SRLG on a VPN basis. When a core network path is setup, the following information allows a CN to lookup the CN diversity information: . L1 VPN Identifier . Path Affinity Set Identifier . Source CN Address . Destination CN Address . List of core network SRLGs (variable) The source CN address and destination CN address are the same addresses in the VPN PIT and correspond to the respective EN address identifiers. Note that all of the information is local to the CN context and is not shared with the EN. The VPN Identifier is associated with an EN. The only value that is signaled from the EN is the Path Affinity Set and optionally the addresses of an existing LSP. The CN stores source and destination CN addresses of the LSP in their native format along with the SRLG information. This information is internal to the core network and is assumed to be known. 2.3. Diversity EXRS Subobject [RFC4874] defines the EXRS ERO subobject. An EXRS is used to identify abstract nodes or resources that must not or should not be used on the path between two inclusive abstract nodes or resources in the explicit route. An EXRS contains one or more subobjects of its own, called EXRS subobjects [RFC4874]. An EXRS MAY include Diversity subobject as specified in this document. In this case, the EXRS format would be as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type | Length | Reserved | Expires January 2015 [Page 25] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |L| Type |Attribute Flags|Exclusion Flags| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLVs ... | // // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The meanings of respective fields in EXRS header are as defined in [RFC4874]. The meanings of respective fields in Diversity subobject are as defined earlier in this document. The processing rules for the EXRS object are unchanged from [RFC4874]. When the EXRS contains one or more Diversity subobject(s), the processing rules specified in Section 2.3 apply to the node processing the ERO with the EXRS subobject. If a loose-hop expansion results in the creation of another loose-hop in the outgoing ERO, the processing node MAY include the EXRS in the newly created loose hop for further processing by downstream nodes. The processing node exception for the EXRS subobject applies to the node processing the ERO. The destination node exception for the EXRS subobject applies to the explicit node identified by the ERO subobject that identifies the next abstract node. This flag is only processed if the L bit is set in the ERO subobject that identifies the next abstract node. The penultimate node exception for the EXRS subobject applies to the node before the explicit node identified by the ERO subobject that identifies the next abstract node. This flag is only processed if the L bit is set in the ERO subobject that identifies the next abstract node. 3. Security Considerations This document does not introduce any additional security issues above those identified in [RFC5920], [RFC2205], [RFC3209], [RFC3473] and [RFC4874]. Expires January 2015 [Page 26] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt 4. IANA Considerations 4.1. New XRO subobject types IANA registry: RSVP PARAMETERS Subsection: Class Names, Class Numbers, and Class Types This document introduces two new subobjects for the EXCLUDE_ROUTE object [RFC4874], C-Type 1. Subobject Description Subobject Type -------------- --------------------- Diversity subobject To be assigned by IANA (suggested value: 36) 4.2. New EXRS subobject types The diversity XRO subobjects are also defined as new EXRS subobjects. 4.3. TLV types for Diversity XRO and EXRS subobjects The following TLV types for Diversity XRO and EXRS subobjects are defined. TLV Description TLV Type --------------- -------- IPv4 Point-to-Point tunnel identifier To be assigned by IANA (suggested value: 1) IPv6 Point-to-Point tunnel identifier To be assigned by IANA (suggested value: 2) IPv4 Path Key To be assigned by IANA (suggested value: 3) IPv6 Path Key To be assigned by IANA (suggested value: 4) IPv4 Path Affinity Set To be assigned by IANA (suggested value: 5) IPv6 Path Affinity Set To be assigned by IANA (suggested value: 6) Expires January 2015 [Page 27] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt 4.4. New RSVP error sub-codes IANA registry: RSVP PARAMETERS Subsection: Error Codes and Globally Defined Error Value Sub- Codes For Error Code "Notify Error" (25) (see [RFC3209]) the following sub-codes are defined. Sub-code Value -------- ----- Route of XRO To be assigned by IANA. tunnel identifier unknown Suggested Value: 13. Failed to respect Exclude Route To be assigned by IANA. Suggested Value: 14. Compliant path exists To be assigned by IANA. Suggested Value: 15. XRO PAS value inferred To be assigned by IANA. Suggested Value: 16 5. Acknowledgements The authors would like to thank Luyuan Fang and Walid Wakim for their review comments. 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [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., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. Expires January 2015 [Page 28] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt [RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes - Extension to Resource ReserVation Protocol- Traffic Engineering (RSVP-TE)", RFC 4874, April 2007. [RFC5553] Farrel, A., Ed., Bradford, R., and JP. Vasseur, "Resource Reservation Protocol (RSVP) Extensions for Path Key Support", RFC 5553, May 2009. 6.2. Informative References [RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter, "Generalized Multiprotocol Label Switching (GMPLS) User-Network Interface (UNI): Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Support for the Overlay Model", RFC 4208, October 2005. [RFC4920] Farrel, A., Ed., Satyanarayana, A., Iwata, A., Fujita, N., and G. Ash, "Crankback Signaling Extensions for MPLS and GMPLS RSVP-TE", RFC 4920, July 2007. [RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel, "Preserving Topology Confidentiality in Inter-Domain Path Computation Using a Path-Key-Based Mechanism", RFC 5520, April 2009. [DRAFT-SRLG-RECORDING] F. Zhang, D. Li, O. Gonzalez de Dios, C. Margaria, "RSVP-TE Extensions for Collecting SRLG Information", draft-ietf-ccamp-rsvp-te-srlg-collect.txt, work in progress. [RFC2205] Braden, R. (Ed.), Zhang, L., Berson, S., Herzog, S. and S. Jamin, "Resource ReserVation Protocol -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual Private Network (VPN) Terminology", RFC 4026, March 2005. [RFC5253] Takeda, T., Ed., "Applicability Statement for Layer 1 Virtual Private Network (L1VPN) Basic Mode", RFC 5253, July 2008. Expires January 2015 [Page 29] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010. Contributor's Addresses Igor Bryskin ADVA Optical Networking Email: ibryskin@advaoptical.com Daniele Ceccarelli Ericsson Email: Daniele.Ceccarelli@ericsson.com Dhruv Dhody Huawei Technologies EMail: dhruv.ietf@gmail.com Oscar Gonzalez de Dios Telefonica I+D Email: ogondio@tid.es Don Fedyk Hewlett-Packard Email: don.fedyk@hp.com Clarence Filsfils Cisco Systems, Inc. Email: cfilsfil@cisco.com Xihua Fu ZTE Email: fu.xihua@zte.com.cn Expires January 2015 [Page 30] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Gabriele Maria Galimberti Cisco Systems Email: ggalimbe@cisco.com Ori Gerstel SDN Solutions Ltd. Email: origerstel@gmail.com Matt Hartley Cisco Systems Email: mhartley@cisco.com Kenji Kumaki KDDI Corporation Email: ke-kumaki@kddi.com Rudiger Kunze Deutsche Telekom AG Email: Ruediger.Kunze@telekom.de Lieven Levrau Alcatel-Lucent Email: Lieven.Levrau@alcatel-lucent.com Cyril Margaria cyril.margaria@gmail.com Julien Meuric France Telecom Orange Email: julien.meuric@orange.com Yuji Tochio Fujitsu Email: tochio@jp.fujitsu.com Xian Zhang Huawei Technologies Email: zhang.xian@huawei.com Authors' Addresses Expires January 2015 [Page 31] Internet Draft draft-ietf-ccamp-lsp-diversity-04.txt Zafar Ali Cisco Systems. Email: zali@cisco.com Dieter Beller Alcatel-Lucent Email: Dieter.Beller@alcatel-lucent.com George Swallow Cisco Systems Email: swallow@cisco.com Fatai Zhang Huawei Technologies Email: zhangfatai@huawei.com Expires January 2015 [Page 32]