INTERNET-DRAFT A. Malis, ed. Intended Status: Proposed Standard Verizon Communications Expires: December 27, 2010 A. Lindem, ed. Ericsson June 25, 2010 Updates to ASON Routing for OSPFv2 Protocols (RFC 5787bis) draft-malis-ccamp-rfc5787bis-00.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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." 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Malis Expires December 27, 2010 [Page 1] INTERNET DRAFT RFC5787bis June 25, 2010 Abstract The ITU-T has defined an architecture and requirements for operating an Automatically Switched Optical Network (ASON). The Generalized Multiprotocol Label Switching (GMPLS) protocol suite is designed to provide a control plane for a range of network technologies including optical networks such as time division multiplexing (TDM) networks including SONET/SDH and Optical Transport Networks (OTNs), and lambda switching optical networks. The requirements for GMPLS routing to satisfy the requirements of ASON routing, and an evaluation of existing GMPLS routing protocols are provided in other documents. This document defines extensions to the OSPFv2 Link State Routing Protocol to meet the requirements for routing in an ASON. Note that this work is scoped to the requirements and evaluation expressed in RFC 4258 and RFC 4652 and the ITU-T Recommendations current when those documents were written. Future extensions of revisions of this work may be necessary if the ITU-T Recommendations are revised or if new requirements are introduced into a revision of RFC 4258. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Conventions Used in This Document . . . . . . . . . . . . 5 2. Routing Areas, OSPF Areas, and Protocol Instances . . . . . . . 5 3. Terminology and Identification . . . . . . . . . . . . . . . . 5 4. Reachability . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. Link Attribute . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Local Adaptation . . . . . . . . . . . . . . . . . . . . . 7 5.2. Bandwidth Accounting . . . . . . . . . . . . . . . . . . . 8 6. Routing Information Scope . . . . . . . . . . . . . . . . . . . 8 6.1. Link Advertisement (Local and Remote TE Router ID Sub-TLV) . . . . . . . . . . . . . . . . . . . . . . . . . 8 6.2. Reachability Advertisement (Local TE Router ID sub-TLV) . 9 7. Routing Information Dissemination . . . . . . . . . . . . . . 10 7.1 Import/Export Rules . . . . . . . . . . . . . . . . . . . 10 7.2 Loop Prevention . . . . . . . . . . . . . . . . . . . . . 11 7.2.1 Inter-RA Export Upward/Downward Sub-TLVs . . . . . . 11 7.2.2 Inter-RA Export Upward/Downward Sub-TLV Processing . 12 8. OSPFv2 Scalability . . . . . . . . . . . . . . . . . . . . . 12 9. Security Considerations . . . . . . . . . . . . . . . . . . . 13 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 13 10.1. Sub-TLVs of the Link TLV . . . . . . . . . . . . . . . 14 Malis Expires December 27, 2010 [Page 2] INTERNET DRAFT RFC5787bis June 25, 2010 10.2. Sub-TLVs of the Node Attribute TLV . . . . . . . . . . 14 10.3. Sub-TLVs of the Router Address TLV . . . . . . . . . . 14 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 11.2. Informative References . . . . . . . . . . . . . . . . 16 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 Appendix A. ASON Terminology . . . . . . . . . . . . . . . . . . 18 Appendix B. ASON Routing Terminology . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 Malis Expires December 27, 2010 [Page 3] INTERNET DRAFT RFC5787bis June 25, 2010 1. Introduction The Generalized Multiprotocol Label Switching (GMPLS) [RFC3945] protocol suite is designed to provide a control plane for a range of network technologies including optical networks such as time division multiplexing (TDM) networks including SONET/SDH and Optical Transport Networks (OTNs), and lambda switching optical networks. The ITU-T defines the architecture of the Automatically Switched Optical Network (ASON) in [G.8080]. [RFC4258] details the routing requirements for the GMPLS suite of routing protocols to support the capabilities and functionality of ASON control planes identified in [G.7715] and in [G.7715.1]. [RFC4652] evaluates the IETF Link State routing protocols against the requirements identified in [RFC4258]. Section 7.1 of [RFC4652] summarizes the capabilities to be provided by OSPFv2 [RFC2328] in support of ASON routing. This document details the OSPFv2 specifics for ASON routing. Multi-layer transport networks are constructed from multiple networks of different technologies operating in a client-server relationship. The ASON routing model includes the definition of routing levels that provide scaling and confidentiality benefits. In multi-level routing, domains called routing areas (RAs) are arranged in a hierarchical relationship. Note that as described in [RFC4652], there is no implied relationship between multi-layer transport networks and multi-level routing. The multi-level routing mechanisms described in this document work for both single-layer and multi-layer networks. Implementations may support a hierarchical routing topology (multi- level) for multiple transport network layers and/or a hierarchical routing topology for a single transport network layer. This document details the processing of the generic (technology- independent) link attributes that are defined in [RFC3630], [RFC4202], and [RFC4203] and that are extended in this document. As detailed in Section 5.2, technology-specific traffic engineering attributes and their processing may be defined in other documents that complement this document. Note that this work is scoped to the requirements and evaluation expressed in [RFC4258] and [RFC4652] and the ITU-T Recommendations current when those documents were written. Future extensions of revisions of this work may be necessary if the ITU-T Recommendations are revised or if new requirements are introduced into a revision of Malis Expires December 27, 2010 [Page 4] INTERNET DRAFT RFC5787bis June 25, 2010 [RFC4258]. 1.1. 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]. The reader is assumed to be familiar with the terminology and requirements developed in [RFC4258] and the evaluation outcomes detailed in [RFC4652]. General ASON terminology is provided in Appendix A. ASON routing terminology is described in Appendix B. 2. Routing Areas, OSPF Areas, and Protocol Instances An ASON routing area (RA) represents a partition of the data plane, and its identifier is used within the control plane as the representation of this partition. RAs are arranged in hierarchical levels such that any one RA may contain multiple other RAs, and is wholly contained by a single RA. Thus, an RA may contain smaller RAs inter-connected by links. The limit of the subdivision results in an RA that contains just two sub- networks interconnected by a single link. An ASON RA can be mapped to an OSPF area, but the hierarchy of ASON RA levels does not map to the hierarchy of OSPF areas. Instead, successive hierarchical levels of RAs MUST be represented by separate instances of the protocol. Thus, inter-level routing information exchange (as described in Section 7) involves the export and import of routing information between protocol instances. An ASON RA may therefore be identified by the combination of its OSPF instance identifier and its OSPF area identifier. With proper and careful network-wide configuration, this can be achieved using just the OSPF area identifier, and this process is RECOMMENDED in this document. These concepts are discussed in Section 7. 3. Terminology and Identification The definition of short-hand terminology introduced in [RFC4652] is repeated here for clarity. - Pi is a physical (bearer/data/transport plane) node. Malis Expires December 27, 2010 [Page 5] INTERNET DRAFT RFC5787bis June 25, 2010 - Li is a logical control plane entity that is associated to a single data plane (abstract) node. Each Li is identified by a unique TE Router ID. The latter is a control plane identifier, defined as the Router Address top-level TLV (Type 1) of the Traffic Engineering (TE) Link State Advertisement (LSA) [RFC3630]. Note: The Router Address top-level TLV definition, processing, and usage remain per [RFC3630]. This TLV specifies a stable IP address of the advertising router (Ri) that is always reachable if there is any IP connectivity to it (e.g., via the Data Communication Network). Moreover, each advertising router advertises a unique, reachable IP address for each Pi on behalf of which it advertises topology information. - Ri is a logical control plane entity that is associated to an OSPF control plane router. The latter is the source for topology information that it generates and shares with other OSPF control plane routers. The Ri is identified by the advertising Router ID as defined in [RFC2328]. The Router ID, which is represented by Ri and which corresponds to the RC-ID [RFC4258], does not enter into the identification of the logical entities representing the data plane resources such as links. The Routing Database (RDB) is associated with the Ri. Note: Aside from the Li/Pi mappings, these identifiers are not assumed to be in a particular entity relationship except that the Ri may have multiple Li's in its scope. The relationship between Ri and Li is simple at any moment in time: an Li may be advertised by only one Ri at any time. However, an Ri may advertise a set of one or more Li's. Hence, the OSPFv2 routing protocol must support a single Ri advertising on behalf of more than one Li. 4. Reachability In order to advertise blocks of reachable address prefixes, a summarization mechanism is introduced that is based on the techniques described in [RFC5786]. For ASON reachability advertisement, blocks of reachable address prefixes are advertised together with the associated data plane node. The data plane node is identified in the control plane by its TE Router ID, as discussed in section 6. In order to support ASON reachability advertisement, the Node Attribute TLV defined in [RFC5786] is used to advertise the combination of a TE Router ID and its set of associated reachable address prefixes. The Node Attribute TLV can contain the following sub-TLVs: Malis Expires December 27, 2010 [Page 6] INTERNET DRAFT RFC5787bis June 25, 2010 - TE Router ID sub-TLV: Length: 4; Defined in Section 6.2 - Node IPv4 Local Address sub-TLV: Length: variable; [RFC5786] - Node IPv6 Local Address sub-TLV: Length: variable; [RFC5786] A router may support multiple data plane nodes as discussed in section 5, and as a result may be required to advertise reachability separately for multiple TE Router ID values. As a consequence, it MUST be possible for the router to originate more than one TE LSA containing the Node Attribute TLV when used for ASON reachability advertisement. Hence, the Node Attribute TLV [RFC5786] advertisement rules must be relaxed for ASON. A Node Attribute TLV MAY appear in more than one TE LSA originated by the RC when the RC is advertising reachability information for a different logical control plane entity (Li) identified by the Local TE Router Sub-TLV (refer to section 6.1). 5. Link Attribute [RFC4652] provides a map between link attributes and characteristics and their representation in sub-TLVs of the top-level Link TLV advertised in TE LSAs [RFC3630] and [RFC4203], with the exception of the local adaptation (refer to Section 5.1). Advertisement of this information SHOULD be supported on a per-layer basis, i.e., one TE LSA per switching capability (and per bandwidth granularity, e.g., low-order virtual container and high-order virtual container). 5.1. Local Adaptation Local adaptation is defined as a TE link attribute (i.e., sub-TLV) that describes the cross/inter-layer relationships. The Interface Switching Capability Descriptor (ISCD) TE Attribute [RFC4202] identifies the ability of the TE link to support cross- connection to another link within the same layer, and the ability to use a locally terminated connection that belongs to one layer as a data link for another layer (adaptation capability). However, the information associated with the ability to terminate connections within that layer (referred to as the termination capability) is embedded with the adaptation capability. For instance, a link between two optical cross-connects will contain at least one ISCD attribute describing the lambda switching capable (LSC) switching capability; whereas a link between an optical cross- connect and an IP/MPLS Label Switch Router (LSR) will contain at least two ISCD attributes: Malis Expires December 27, 2010 [Page 7] INTERNET DRAFT RFC5787bis June 25, 2010 one for the description of the LSC termination capability and one for the packet switching capable (PSC) adaptation capability. In OSPFv2, the Interface Switching Capability Descriptor (ISCD) is a sub-TLV (type 15) of the top-level Link TLV (type 2) [RFC4203]. The adaptation and termination capabilities are advertised using two separate ISCD sub-TLVs within the same top-level Link TLV. Per [RFC4202] and [RFC4203], an interface MAY have more than one ISCD sub-TLV. Hence, the corresponding advertisements should not result in any compatibility issues. However, some link types may support several different signal types that are modeled as separate layers in the G.805 model [G.805] (e.g., SDH links may simultaneously support VC-3, VC-4, VC-4-4c, VC-4-16c and VC-4-64c signals). Optimization refinements to reduce the overhead of advertising link characteristics separately for each signal type may be defined. Further refinement of the ISCD sub-TLV for multi-layer networks is outside the scope of this document. 5.2. Bandwidth Accounting GMPLS routing defines an Interface Switching Capability Descriptor (ISCD) that delivers, among other things, information about the (maximum/minimum) bandwidth per priority that a Label Switched Path (LSP) can use. Per [RFC4202] and [RFC4203], one or more ISCD sub-TLVs can be associated with an interface. This information, combined with the Unreserved Bandwidth (sub-TLV defined in [RFC3630], Section 2.5.8), provides the basis for bandwidth accounting. In the ASON context, additional information may be included when the representation and information in the other advertised fields are not sufficient for a specific technology (e.g., SDH). The definition of technology-specific information elements is beyond the scope of this document. Some technologies will not require additional information beyond what is already defined in [RFC3630], [RFC4202], and [RFC4203]. 6. Routing Information Scope 6.1. Link Advertisement (Local and Remote TE Router ID Sub-TLV) A Router ID (Ri) advertising on behalf multiple TE Router IDs (Li's) creates a 1:N relationship between the Router ID and the TE Router ID. As the link local and link remote (unnumbered) ID association is not unique per node (per Li), the advertisement needs to indicate the remote Lj value and rely on the initial discovery process to retrieve Malis Expires December 27, 2010 [Page 8] INTERNET DRAFT RFC5787bis June 25, 2010 the [Li;Lj] relationship. In brief, as unnumbered links have their ID defined on a per-Li basis, the remote Lj needs to be identified to scope the link remote ID to the local Li. Therefore, the routing protocol MUST be able to disambiguate the advertised TE links so that they can be associated with the correct TE Router ID. For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Link TLV is introduced that defines the Local and Remote TE Router ID. The Type field of the Local and Remote TE Router ID sub-TLV is assigned a value TBD. The Length field takes the value 8. The Value field of this sub-TLV contains 4 octets of the Local TE Router Identifier followed by 4 octets of the Remote TE Router Identifier. The value of the Local and Remote TE Router Identifier SHOULD NOT be set to 0. The format of the Local and Remote TE Router ID sub-TLV is: 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 (8) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This sub-TLV MUST be included as a sub-TLV of the top-level Link TLV if the Router ID is advertising on behalf of more than one TE Router ID. This sub-TLV SHOULD be omitted if the Ri is only advertising on behalf of a single Li. Note: The Link ID sub-TLV that identifies the other end of the link (i.e., Router ID of the neighbor for point-to-point links) MUST appear exactly once per Link TLV. This sub-TLV MUST be processed as defined in [RFC3630]. 6.2. Reachability Advertisement (Local TE Router ID sub-TLV) When the Router ID is advertised on behalf of multiple TE Router IDs (Li's), the routing protocol MUST be able to associate the advertised reachability information with the correct TE Router ID. For this purpose, a new sub-TLV of the OSPFv2 TE LSA top-level Node Attribute TLV is introduced. This TLV associates the local prefixes (see above) to a given TE Router ID. Malis Expires December 27, 2010 [Page 9] INTERNET DRAFT RFC5787bis June 25, 2010 The Type field of the Local TE Router ID sub-TLV is assigned a value TBD. The Length field takes the value 4. The Value field of this sub-TLV contains the Local TE Router Identifier [RFC3630] encoded over 4 octets. The format of the Local TE Router ID sub-TLV is: 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 (4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This sub-TLV is only required to be included as part of the Node Attribute TLV if the Router ID is advertising on behalf of more than one TE Router ID. In any other case, this sub-TLV SHOULD be omitted. 7. Routing Information Dissemination An ASON routing area (RA) represents a partition of the data plane, and its identifier is used within the control plane as the representation of this partition. An RA may contain smaller RAs inter-connected by links. ASON RA levels do not map directly to OSPF areas. Rather, hierarchical levels of RAs are represented by separate OSPF protocol instances. Routing controllers (RCs) supporting RAs disseminate information downward and upward in this ASON hierarchy. The vertical routing information dissemination mechanisms described in this section do not introduce or imply hierarchical OSPF areas. RCs supporting RAs at multiple levels are structured as separate OSPF instances with routing information exchange between levels described by import and export rules between these instances. The functionality described herein does not pertain to OSPF areas or OSPF Area Border Router (ABR) functionality. 7.1 Import/Export Rules RCs supporting RAs disseminate information upward and downward in the hierarchy by importing/exporting routing information as TE LSAs. TE LSAs are area-scoped opaque LSAs with opaque type 1 [RFC3630]. The information that MAY be exchanged between adjacent levels includes the Router Address, Link, and Node Attribute top-level TLVs. The imported/exported routing information content MAY be transformed, e.g., filtered or aggregated, as long as the resulting routing Malis Expires December 27, 2010 [Page 10] INTERNET DRAFT RFC5787bis June 25, 2010 information is consistent. In particular, when more than one RC is bound to adjacent levels and both are allowed to import/export routing information, it is expected that these transformations are performed in a consistent manner. Definition of these policy-based mechanisms is outside the scope of this document. In practice, and in order to avoid scalability and processing overhead, routing information imported/exported downward/upward in the hierarchy is expected to include reachability information (see Section 4) and, upon strict policy control, link topology information. 7.2 Loop Prevention When more than one RC is bound to an adjacent level of the ASON hierarchy, and is configured to export routing information upward or downward, a specific mechanism is required to avoid looping of routing information. Looping is the re-advertisement of routing information into an RA that had previously advertised that routing information upward or downward into an upper or lower level RA in the ASON hierarchy. For example, without loop prevention mechanisms, this could happen when the RC advertising routing information downward in the hierarchy is not the same one that advertises routing upward in the hierarchy. 7.2.1 Inter-RA Export Upward/Downward Sub-TLVs The Inter-RA Export Sub-TLVs can be used to prevent the re- advertisement of OSPF TE routing information into an RA which previously advertised that information. The type value TBD will indicate that the associated routing information has been exported downward. The type value TBD will indicate that the associated routing information has been exported upward. While it is not required for routing information exported downward, both Sub-TLVs will include the Routing Area (RA) ID from the which the routing information was exported. This RA is not necessarily the RA originating the routing information but RA from which the information was immediately exported. These additional Sub-TLVs MAY be carried in TE LSAs that include any of the following top-level TLVs: - Router Address top-level TLV - Link top-level TLV - Node Attribute top-level TLV The Type field of the Inter-RA Export Upward and Inter-RA Export Downward sub-TLVs are respectively assigned the values TBD1 and TBD2. Malis Expires December 27, 2010 [Page 11] INTERNET DRAFT RFC5787bis June 25, 2010 The Length of the Associated RA ID TLV is 4 octets. The Value field in these sub-TLVs contains the associated RA ID. The RA ID value must be a unique identifier for the RA within the ASON routing domain. The format of the Inter-RA Export Upward and Inter-RA Export Downward Sub-TLVs is graphically depicted below: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Upward/Downward Type | Length (4) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Associated RA ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7.2.2 Inter-RA Export Upward/Downward Sub-TLV Processing TE LSAs MAY be imported or exported downward or upward in the ASON routing hierarchy. The direction and advertising RA ID are advertised in an Inter-RA Export Upward/Downward Sub-TLV. They MUST be retained by the receiving RA with the associated routing information. When exporting routing information upward in the ASON routing hierarchy, any information received from a level above, i.e., tagged with an Inter-RA Export Downward Sub-TLV, MUST NOT be exported upward. Since an RA at level N is contained by a single RA at level N+1, this is the only checking that is necessary and the associated RA ID is used solely for informational purposes. When exporting routing information downward in the ASON routing hierarchy, any information received from a level below, i.e., tagged with an Inter-RA Expert Upward Sub-TLV MUST NOT be exported downward if the target RA ID matches the RA ID associated with the routing information. This additional checking is required for routing information exported downward since a single RA at level N+1 may contain multiple RAs at level N in the ASON routing hierarchy. In order words, routing information MUST NOT be exported downward into the RA from which it was received. 8. OSPFv2 Scalability The extensions described herein are only applicable to ASON routing domains and it is not expected that the attendant Ri/Li reachability and link information will ever be mixed with global or local IP routing information. If there ever were a requirement for a given RC to participate in both domains, separate OSPFv2 instances would be utilized. However, in a multi-level ASON hierarchy, the potential volume of information could be quite large and the recommendations in Malis Expires December 27, 2010 [Page 12] INTERNET DRAFT RFC5787bis June 25, 2010 this section SHOULD be followed by RC implementing this specification. - Routing information exchange upward/downward in the hierarchy between adjacent RAs SHOULD, by default, be limited to reachability information. In addition, several transformations such as prefix aggregation are RECOMMENDED to reduce the amount of information imported/exported by a given RC when such transformations will not impact consistency. - Routing information exchange upward/downward in the ASON hierarchy involving TE attributes MUST be under strict policy control. Pacing and min/max thresholds for triggered updates are strongly RECOMMENDED. - The number of routing levels MUST be maintained under strict policy control. 9. Security Considerations This document specifies the contents and processing of OSPFv2 TE LSAs [RFC3630] and [RFC4202]. The TE LSA extensions defined in this document are not used for SPF computation, and have no direct effect on IP routing. Additionally, ASON routing domains are delimited by the usual administrative domain boundaries. Any mechanisms used for securing the exchange of normal OSPF LSAs can be applied equally to all TE LSAs used in the ASON context. Authentication of OSPFv2 LSA exchanges (such as OSPF cryptographic authentication [RFC2328] and [RFC5709]) can be used to secure against passive attacks and provide significant protection against active attacks. [RFC5709] defines a mechanism for authenticating OSPFv2 packets by making use of the HMAC algorithm in conjunction with the SHA family of cryptographic hash functions. If a stronger authentication were believed to be required, then the use of a full digital signature [RFC2154] would be an approach that should be seriously considered. Use of full digital signatures would enable precise authentication of the OSPF router originating each OSPF link-state advertisement, and thereby provide much stronger integrity protection for the OSPF routing domain. 10. IANA Considerations This document is classified as Standards Track. It defines new sub- TLVs for inclusion in OSPF TE LSAs. According to the assignment policies for the registries of code points for these sub-TLVs, values must be assigned by IANA [RFC3630]. Malis Expires December 27, 2010 [Page 13] INTERNET DRAFT RFC5787bis June 25, 2010 The following subsections summarize the required sub-TLVs. 10.1. Sub-TLVs of the Link TLV This document defines the following sub-TLVs of the Link TLV advertised in the OSPF TE LSA: - Local and Remote TE Router ID sub-TLV - Associated RA ID sub-TLV - Inter-RA Export Upward sub-TLV - Inter-RA Export Downward sub-TLV Codepoints for these Sub-TLVs should be allocated from the "Types for sub-TLVs of TE Link TLV (Value 2)" registry standards action range (0 - 32767) [RFC3630]. Note that the same values for the Associated RA ID sub-TLV, Inter-RA Export Upward sub-TLV, and Inter-RA Export Downward Sub-TLV MUST be used when they appear in the Link TLV, Node Attribute TLV, and Router Address TLV. 10.2. Sub-TLVs of the Node Attribute TLV This document defines the following sub-TLVs of the Node Attribute TLV advertised in the OSPF TE LSA: - Local TE Router ID sub-TLV - Associated RA ID sub-TLV - Inter-RA Export Upward sub-TLV - Inter-RA Export Downward sub-TLV Codepoints for these Sub-TLVs should be assigned from the "Types for sub-TLVs of TE Node Attribute TLV (Value 5)" registry standards action range (0 - 32767) [RFC5786]. Note that the same values for the Associated RA ID sub-TLV, Inter-RA Export Upward sub-TLV, and Inter-RA Export Downward Sub-TLV MUST be used when they appear in the Link TLV, Node Attribute TLV, and Router Address TLV. 10.3. Sub-TLVs of the Router Address TLV The Router Address TLV is advertised in the OSPF TE LSA [RFC3630]. Since this TLV currently has no Sub-TLVs defined, a "Types for sub- TLVs of Router Address TLV (Value 1)" registry must be defined. The registry guidelines for the assignment of types for sub-TLVs of the Router Address TLV are as follows: Malis Expires December 27, 2010 [Page 14] INTERNET DRAFT RFC5787bis June 25, 2010 o Types in the range 0-32767 are to be assigned via Standards Action. o Types in the range 32768-32777 are for experimental use; these will not be registered with IANA, and MUST NOT be mentioned by RFCs. o Types in the range 32778-65535 are not to be assigned at this time. Before any assignments can be made in this range, there MUST be a Standards Track RFC that specifies IANA Considerations that covers the range being assigned. This document defines the following sub-TLVs for inclusion in the Router Address TLV: - Associated RA ID sub-TLV - Inter-RA Export Upward sub-TLV - Inter-RA Export Downward sub-TLV Codepoints for these Sub-TLVs should be allocated from the "Types for sub-TLVs of Router Address TLV (Value 1)" registry standards action range (0 - 32767). Note that the same values for the Associated RA ID sub-TLV, Inter-RA Export Upward sub-TLV, and Inter-RA Export Downward Sub-TLV MUST be used when they appear in the Link TLV, Node Attribute TLV, and Router Address TLV. 11. References 11.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, September 2003. [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, October 2005. Malis Expires December 27, 2010 [Page 15] INTERNET DRAFT RFC5787bis June 25, 2010 [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005. [RFC5786] Aggarwal, R. and K. Kompella, "Advertising a Router's Local Addresses in OSPF TE Extensions", RFC 5786, March 2010. 11.2. Informative References [RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with Digital Signatures", RFC 2154, June 1997. [RFC4258] Brungard, D., Ed., "Requirements for Generalized Multi- Protocol Label Switching (GMPLS) Routing for the Automatically Switched Optical Network (ASON)", RFC 4258, November 2005. [RFC4652] Papadimitriou, D., Ed., Ong, L., Sadler, J., Shew, S., and D. Ward, "Evaluation of Existing Routing Protocols against Automatic Switched Optical Network (ASON) Routing Requirements", RFC 4652, October 2006. [RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, M., Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA Cryptographic Authentication", RFC 5709, October 2009. For information on the availability of ITU Documents, please see http://www.itu.int. [G.7715] ITU-T Rec. G.7715/Y.1306, "Architecture and Requirements for the Automatically Switched Optical Network (ASON)", June 2002. [G.7715.1] ITU-T Draft Rec. G.7715.1/Y.1706.1, "ASON Routing Architecture and Requirements for Link State Protocols", November 2003. [G.805] ITU-T Rec. G.805, "Generic functional architecture of transport networks)", March 2000. [G.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the Automatically Switched Optical Network (ASON)," November 2001 (and Revision, January 2003). Malis Expires December 27, 2010 [Page 16] INTERNET DRAFT RFC5787bis June 25, 2010 12. Acknowledgements The editors would like to thank Dimitri Papadimitriou for editing RFC 5787, from which this document is derived, and Lyndon Ong and Remi Theillaud for their useful comments and suggestions. Malis Expires December 27, 2010 [Page 17] INTERNET DRAFT RFC5787bis June 25, 2010 Appendix A. ASON Terminology This document makes use of the following terms: Administrative domain: (See Recommendation [G.805].) For the purposes of [G7715.1], an administrative domain represents the extent of resources that belong to a single player such as a network operator, a service provider, or an end-user. Administrative domains of different players do not overlap amongst themselves. Control plane: performs the call control and connection control functions. Through signaling, the control plane sets up and releases connections, and may restore a connection in case of a failure. (Control) Domain: represents a collection of (control) entities that are grouped for a particular purpose. The control plane is subdivided into domains matching administrative domains. Within an administrative domain, further subdivisions of the control plane are recursively applied. A routing control domain is an abstract entity that hides the details of the RC distribution. External NNI (E-NNI): interfaces located between protocol controllers between control domains. Internal NNI (I-NNI): interfaces located between protocol controllers within control domains. Link: (See Recommendation G.805.) A "topological component" that describes a fixed relationship between a "subnetwork" or "access group" and another "subnetwork" or "access group". Links are not limited to being provided by a single server trail. Management plane: performs management functions for the transport plane, the control plane, and the system as a whole. It also provides coordination between all the planes. The following management functional areas are performed in the management plane: performance, fault, configuration, accounting, and security management. Management domain: (See Recommendation G.805.) A management domain defines a collection of managed objects that are grouped to meet organizational requirements according to geography, technology, policy, or other structure, and for a number of functional areas such as configuration, security, (FCAPS), for the purpose of providing control in a consistent manner. Management domains can be disjoint, contained, or overlapping. As such, the resources Malis Expires December 27, 2010 [Page 18] INTERNET DRAFT RFC5787bis June 25, 2010 within an administrative domain can be distributed into several possible overlapping management domains. The same resource can therefore belong to several management domains simultaneously, but a management domain shall not cross the border of an administrative domain. Subnetwork Point (SNP): The SNP is a control plane abstraction that represents an actual or potential transport plane resource. SNPs (in different subnetwork partitions) may represent the same transport resource. A one-to-one correspondence should not be assumed. Subnetwork Point Pool (SNPP): A set of SNPs that are grouped together for the purposes of routing. Termination Connection Point (TCP): A TCP represents the output of a Trail Termination function or the input to a Trail Termination Sink function. Transport plane: provides bidirectional or unidirectional transfer of user information, from one location to another. It can also provide transfer of some control and network management information. The transport plane is layered; it is equivalent to the Transport Network defined in Recommendation G.805. User Network Interface (UNI): interfaces are located between protocol controllers between a user and a control domain. Note: There is no routing function associated with a UNI reference point. Appendix B. ASON Routing Terminology This document makes use of the following terms: Routing Area (RA): an RA represents a partition of the data plane, and its identifier is used within the control plane as the representation of this partition. Per [G.8080], an RA is defined by a set of sub-networks, the links that interconnect them, and the interfaces representing the ends of the links exiting that RA. An RA may contain smaller RAs inter-connected by links. The limit of subdivision results in an RA that contains two sub- networks interconnected by a single link. Routing Database (RDB): a repository for the local topology, network topology, reachability, and other routing information that is updated as part of the routing information exchange and may additionally contain information that is configured. The RDB may contain routing information for more than one routing area (RA). Malis Expires December 27, 2010 [Page 19] INTERNET DRAFT RFC5787bis June 25, 2010 Routing Components: ASON routing architecture functions. These functions can be classified as protocol independent (Link Resource Manager or LRM, Routing Controller or RC) or protocol specific (Protocol Controller or PC). Routing Controller (RC): handles (abstract) information needed for routing and the routing information exchange with peering RCs by operating on the RDB. The RC has access to a view of the RDB. The RC is protocol independent. Note: Since the RDB may contain routing information pertaining to multiple RAs (and possibly to multiple layer networks), the RCs accessing the RDB may share the routing information. Link Resource Manager (LRM): supplies all the relevant component and TE link information to the RC. It informs the RC about any state changes of the link resources it controls. Protocol Controller (PC): handles protocol-specific message exchanges according to the reference point over which the information is exchanged (e.g., E-NNI, I-NNI), and internal exchanges with the RC. The PC function is protocol dependent. Authors' Addresses Andrew G. Malis Verizon Communications 117 West St. Waltham MA 02451 USA EMail: andrew.g.malis@verizon.com Acee Lindem Ericsson 102 Carric Bend Court Cary, NC 27519 EMail: acee.lindem@ericsson.com Malis Expires December 27, 2010 [Page 20]