CCAMP Working Group Dimitri Papadimitriou (Alcatel) Internet Draft Category: Standard Expiration Date: March 2006 October 2005 Link State Routing Protocols Extensions for ASON Routing draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Copyright Notice Copyright (C) The Internet Society (2005). All Rights Reserved. Abstract The Generalized MPLS (GMPLS) suite of protocols has been defined to control different switching technologies as well as different applications. These include support for requesting TDM connections including SONET/SDH and Optical Transport Networks (OTNs). This document provides the extensions of the IETF Link State Routing Protocols to meet the routing requirements for an Automatically Switched Optical Network (ASON) as defined by ITU-T. D.Papadimitriou et al. - Expires March 2006 1 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 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 [ASON-RR] and the evaluation outcomes detailed in [ASON-EVAL]. 2. Introduction There are certain capabilities that are needed to support the ITU-T Automatically Switched Optical Network (ASON) control plane architecture as defined in [G.8080]. [ASON-RR] 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]. [ASON-EVAL] evaluates the IETF Link State Routing Protocols against the requirements identified in [ASON-RR]. Candidate routing protocols are IGP (OSPFv2 and IS-IS). ASON (Routing) terminology sections are provided in Appendix 1 and 2. 3. Reachability 3.1 OSPFv2 In order to advertise blocks of reachable address prefixes a summarization mechanism is introduced that complements the techniques described in [OSPF-NODE]. This extension takes the form of a network mask (a 32-bit number indicating the range of IP addresses residing on a single IP network/subnet). The set of local addresses are carried in an OSPF TE LSA node attribute TLV (a specific sub-TLV is defined per address family, e.g., IPv4 and IPv6). The proposed solution is to advertise the local address prefixes of a router as new sub-TLVs of the (OSPFv2 TE LSA) Node Attribute top level TLV (of Type TBD). This document defines the following sub- TLVs: - Node IPv4 Local Prefix sub-TLV: Type 3 - Length: variable - Node IPv6 Local Prefix sub-TLV: Type 4 - Length: variable 3.1.1 Node IPv4 local prefix sub-TLV The node IPv4 local prefix sub-TLV has a type of 3 and contains one or more local IPv4 prefixes. It has the following format: D.Papadimitriou et al. - Expires March 2006 2 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 3 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Network Mask 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Address 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Network Mask n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Address n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The length is set to 8 * n where n is the number of local prefixes included in the sub-TLV. Network mask: A 32-bit number indicating the IPv4 address mask for the advertised destination prefix. Each pair listed as part of this sub- TLV represents a reachable destination prefix hosted by the advertising Router ID. The local addresses that can be learned from TE LSAs i.e. router address and TE interface addresses SHOULD not be advertised in the node IPv4 local prefix sub-TLV. 3.1.2 Node IPv6 local prefix sub-TLV The node IPv6 local prefix sub-TLV has a type of 4 and contains one or more local IPv6 prefixes. IPv6 Prefix Representation uses RFC 2740 Section A.4.1. It has the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 4 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PrefixLength | PrefixOptions | (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | IPv6 Address Prefix 1 | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . D.Papadimitriou et al. - Expires March 2006 3 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PrefixLength | PrefixOptions | (0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | IPv6 Address Prefix n | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ PrefixLength: length in bits of the prefix. PrefixOptions: 8-bit field describing various capabilities associated with the prefix (see [RFC2740] Section A.4.2). Address Prefix: encoding of the prefix itself as an even multiple of 32-bit words, padding with zero bits as necessary. The Length is set to Sum[n][4 + #32-bit words/4] where n is the number of local prefixes included in the sub-TLV. The local addresses that can be learned from TE LSAs i.e. router address and TE interface addresses SHOULD not be advertised in the node IPv6 local prefix sub-TLV. 3.2 IS-IS A similar mechanism does not exist for IS-IS as the Extended IP Reachability TLV [RFC3784] focuses on IP reachable end-points (terminating points), as its name indicates. Solution TBD 4. Link Attribute 4.1 Local Adaptation The Local Adaptation is defined as TE link attribute (i.e. sub-TLV) that describes the cross/inter-layer relationships. This information is encoded as an Interface Adaptation Capability Descriptor (IACD). In OSPF, the Interface Adaptation Capability Descriptor is a sub-TLV (of type TBA) of the Link TLV (of type 2). In IS-IS, the Interface Adaptation Capability Descriptor is a sub- TLV (of type TBA) of the Extended IS Reachability TLV (of type 22). 4.2 Technology Specific Bandwidth Accounting GMPLS Routing defines an Interface Switching Capability Descriptor (ISCD) that delivers among others the information about the (maximum/minimum) bandwidth per priority an LSP can make use of. D.Papadimitriou et al. - Expires March 2006 4 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 In the ASON context, accounting on per timeslot basis using 32-bit tuples of the form may optionally extend the technology specific information part of the ISCD sub-TLV. In OSPF, the Interface Switching Capability Descriptor is a sub-TLV (of type 15) of the Link TLV (of type 2). In IS-IS, the Interface Switching Capability Descriptor is a sub-TLV (of type 21) of the Extended IS Reachability TLV (of type 22). 5. Routing Information Scope The Ri is a logical control plane entity that is associated to a control plane "router". The latter is the source for topology information that it generates and shares with other control plane "routers". The Ri is identified by the (advertising) Router_ID. The routing protocol MUST support a single Ri advertising on behalf of more than one Li. Each Li is identified by a unique TE Router ID. 5.1 Link Advertisement (Local and Remote TE Router ID sub-TLV) A Router_ID (Ri) advertising on behalf multiple TE Router_ID (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 unicity), the advertisement needs to indicate the remote Lj value and rely on the initial discovery process to retrieve the [Li;Lj] relationship. In brief, as unnumbered links have their ID defined on per Li bases, 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. 5.1.1 OSPFv2 For this purpose, a new sub-TLV of the (OSPFv2 TE LSA) top level Link TLV is introduced that defines the local and the remote TE_Router_ID. The type of this sub-TLV is 17, and length is eight octets. The value field of this sub-TLV contains four octets of Local TE Router Identifier followed by four octets of Remote TE Router Identifier. The value of the Remote TE Router Identifier SHOULD NOT be set to 0. The format of this sub-TLV is the following: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 17 | Length | D.Papadimitriou et al. - Expires March 2006 5 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This sub-TLV is optional and SHOULD only be included as part of the top level Link 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. 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. 5.1.2 IS-IS TBD 5.1 Reachability Advertisement (Local TE Router ID sub-TLV) When the Router_ID advertises on behalf of multiple TE Router_IDs, the routing protocol MUST be able to associate the advertised reachability information with the correct TE Router ID. 5.2.1 OSPFv2 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 (sub-TLV 3 and 4, see above) to a given TE Router_ID. The type of this sub-TLV is 5, and length is four octets. The value field of this sub-TLV contains four octets of Local TE Router Identifier. The format of this sub-TLV is the following: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 5 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Local TE Router Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This sub-TLV is optional and SHOULD only 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. 5.2.2 IS-IS D.Papadimitriou et al. - Expires March 2006 6 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 TBD 7. OSPFv2 Extensions and Compatibility All extensions proposed as part of this document, are addressed into the OSPFv2 TE LSA: o) Router Address top level TLV (Type 1): - no new sub-TLV o) Link top level TLV (Type 2): - Local and Remote TE Router ID sub-TLV: optional sub-TLV for scoping link attributes per TE_Router ID - Interface Adaptation Capability Descriptor sub-TLV: optional sub-TLV that describes the local adaptation capabilities o) Node Attribute top level TLV (Type TBD): - Node IPv4 Local Prefix sub-TLVs: optional sub-TLV for IPv4 reachability advertisement - Node IPv6 Local Prefix sub-TLVs: optional sub-TLV for IPv6 reachability advertisement - Local TE Router ID sub-TLV: optional sub-TLV for scoping reachability per TE_Router ID 8. IS-IS Extensions and Compatibility TBD 9. Acknowledgements The authors would like to thank Alan Davey and Adrian Farrel for their useful comments and suggestions. 10. References 11.1 Normative References [GMPLS-RTG] Kompella, K. (Editor) et al., "Routing Extensions in Support of Generalized MPLS," Internet Draft (work in progress), draft-ietf-ccamp-gmpls-routing-09.txt, October 2003. [OSPF-NODE] R.Aggarwal, and K.Kompella, "Advertising a Router's Local Addresses in OSPF TE Extensions," Internet Draft, (work in progress), draft-ietf-ospf-te-node-addr- 02.txt, March 2005. [RFC2026] S.Bradner, "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. [RFC2328] J.Moy, "OSPF Version 2", RFC 2328, April 1998. D.Papadimitriou et al. - Expires March 2006 7 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 [RFC2740] R.Coltun et al. "OSPF for IPv6", RFC 2740, December 1999. [RFC2119] S.Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3477] K.Kompella et al. "Signalling Unnumbered Links in Resource ReSerVation Protocol - Traffic Engineering (RSVP-TE)", RFC 3477, January 2003. [RFC3630] D.Katz et al. "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, September 2003. [RFC3667] S.Bradner, "IETF Rights in Contributions", BCP 78, RFC 3667, February 2004. [RFC3668] S.Bradner, Ed., "Intellectual Property Rights in IETF Technology", BCP 79, RFC 3668, February 2004. [RFC3784] H.Smit and T.Li, "Intermediate System to Intermediate System (IS-IS) Extensions for Traffic Engineering (TE)," RFC 3784, June 2004. [RFC3946] E.Mannie, and D.Papadimitriou, (Editors) et al., "Generalized Multi-Protocol Label Switching Extensions for SONET and SDH Control," RFC 3946, October 2004. 8.2 Informative References [ASON-RR] C.Hopps et al. "Evaluation of existing Routing Protocols against ASON Routing Requirements", Work in progress, draft-ietf-ccamp-gmpls-ason-routing-eval-01.txt, July 2005. [ASON-EVAL] W.Alanqar et al. "Requirements for Generalized MPLS (GMPLS) Routing for Automatically Switched Optical Network (ASON)," Work in progress, draft-ietf-ccamp- gmpls-ason-routing-reqts-05.txt, October 2004. 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.8080] ITU-T Rec. G.8080/Y.1304, "Architecture for the Automatically Switched Optical Network (ASON)," D.Papadimitriou et al. - Expires March 2006 8 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 November 2001 (and Revision, January 2003). 9. Author's Addresses Dimitri Papadimitriou (Alcatel) Francis Wellensplein 1, B-2018 Antwerpen, Belgium Phone: +32 3 2408491 EMail: dimitri.papadimitriou@alcatel.be D.Papadimitriou et al. - Expires March 2006 9 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 Appendix 1: 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 which 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 are located between protocol controllers between control domains. Internal NNI (I-NNI): interfaces are located between protocol controllers within control domains. Link: (see Recommendation G.805) a "topological component" which 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 which 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 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 D.Papadimitriou et al. - Expires March 2006 10 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 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 bi-directional 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 G.805 Recommendation. 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. D.Papadimitriou et al. - Expires March 2006 11 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 Appendix 2: ASON Routing Terminology This document makes use of the following terms: Routing Area (RA): a 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] a 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. A RA may contain smaller RAs inter-connected by links. The limit of subdivision results in a RA that contains two sub-networks interconnected by a single link. Routing Database (RDB): 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). Routing Components: ASON routing architecture functions. These functions can be classified as protocol independent (Link Resource Manager or LRM, Routing Controller or RC) and 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. D.Papadimitriou et al. - Expires March 2006 12 draft-dimitri-ccamp-gmpls-ason-routing-sol-00.txt October 2005 Full Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTSOR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. D.Papadimitriou et al. - Expires March 2006 13