CCAMP Working Group E. Mannie (Ebone) Internet Draft D. Papadimitriou (Alcatel) Expiration Date: August 2002 Document: draft-mannie-ccamp-gmpls- sonet-sdh-ospf-isis-00.txt February 2002 GMPLS Extensions to OSPF and IS-IS for SONET/SDH Control draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document discusses and explains some of the extensions required in existing IGP routing protocols to support sub-sequent signalling for dynamically established SONET/SDH circuits using GMPLS-based control plane architecture [GMPLS-ARCH]. In particular, it specifies the GMPLS routing extensions to OSPF and IS-IS routing protocols for SONET/SDH networks using [GMPLS-RTG] as guideline. The current document is based on the Traffic Engineering (TE) extensions defined in [OSPF-TE] and [ISIS-TE]. It supports link bundling (also referred to as TE-Links) as defined in [MPLS-BDL]. The document proposes several new sub-TLVs for SONET/SDH network control which complement those proposed in [GMPLS-OSPF-TE] and [GMPLS-ISIS-TE]. The proposed encoding does not preclude any further integration in the before mentioned documents that the current one complements. Expires August 2002 [Page 1] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 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. 2. Introduction This document is based on Traffic Engineering (TE) extensions defined in [OSPF-TE] and [ISIS-TE]. [GMPLS-OSPF-TE] and [GMPLS-ISIS- TE] have extended these attributes in the GMPLS context. The current proposal also uses the notion Link Bundling as defined in [MPLS-BDL]. A set of data bearing links between two adjacent GMPLS nodes (or simply nodes) is defined as a TE-link, which is identified by a TE link ID. GMPLS currently integrates the TE-link by detailing among others that several links having the same Traffic Engineering (TE) capabilities (i.e. same TE metric, same set of Resource Class and same Switching capability) can be advertised as a single TE-link. Such TE-links are referred to as link bundles whose individual data bearing link (or simply links) are referred to as component links; moreover, there is no longer a one-to-one association between a regular routing adjacency and a TE-link. In order to enable distributed SONET/SDH network control, the IGP routing protocol needs to transport two different sets (or types) of information. A set that describes the link capabilities of a SONET/ SDH GMPLS node (or simply a node, in this context), independently of their usage, and a set that describes (in some appropriate manner) the resources (or SONET/SDH signals, more precisely the timeslots) that are in use at each TE link. The first set can be defined as being driven by less frequent updates (since TE link capabilities changes are not expected to be frequent) while the second would follow update interval values as than the one used for any other non-technology dependent TE Link attribute. We consider here that when this frequency is very low the corresponding TE-link capability is static; by opposition, other are referred to as dynamic. The TLVs describing the capabilities of SONET/SDH TE-links are separately defined for LOVC/VT and HOVC/STS SPE: - LS-MC TLV : Link SONET/SDH Multiplex Capability TLV - LS-CC TLV : Link SONET/SDH Concatenation Capability TLV The TLVs describing the dynamic status of a SONET/SDH TE-Link is: - LS-UT-TLV : Link SONET/SDH number of Unallocated Timeslot TLV Expires January 2002 [Page 2] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 When using OSPF, GMPLS TE links can be advertised using Opaque LSAs (Link State Advertisements) of Type 10. The Traffic Engineering (TE) LSA, whose area flooding scope is specified [RFC-2370], has one top- level Type/Length/ Value (TLV) triplet and one or more nested sub- TLVs for extensibility. The top-level TLV can take one of two values (1) Router Address (referred to as the Node TLV) or (2) TE- Link TLV. So here, we propose to extend the current sub-TLV set of the latter. When using IS-IS, GMPLS TE links are advertised using LS PDUs. TE Attributes TLVs are defined sub-TLV of the Extended IS Reachability TLV (TLV 22) see [ISIS-TE]. 3. Additional Considerations Between two adjacent nodes, several links having the same Traffic Engineering (TE) capabilities (i.e. same TE metric, same set of Resource Class and same Switching capability) can be advertised as a single TE-link, such TE-links are referred to as link bundles. The individual link (or data bearing links) belonging to a given bundle are referred to as component links. Also there is no longer a one- to-one association between a regular routing adjacency and a TE- link. The result is that each component of a bundle must have the same SONET/SDH multiplexing and concatenation capabilities as defined later in this draft. The two corresponding TLVs (LS-MC and LS-CC) are specified once, but apply to each component. Thus, no per component information or identification is required for these TLVs. The Link SONET/SDH UT TLV defined later gives the total number of unallocated (identical) components in a TE-Link. Combined with the Link Property correlation (see [LMP]) of component links in TE-links, i.e. link bundling, this capability helps in removing the problem of having to potentially flood a huge amount of routing information. For instance, with a group of 10 fibers and 40 wavelengths per fiber, each of them supporting an STM-64, there are potentially 76800 VC-3 timeslots that can be allocated on that TE- link and that have therefore to be advertised to all nodes in the same routing domain. The most efficient way to proceed on a per-TE Link basis is to advertise the number of unallocated timeslots, such that after the initial advertisement, each node within a given routing area is aware of total capacity per TE-Link (see Section 5.1). Despite being bundled, the usage of each component link in a TE link may differ completely. For example, in a TE link comprising two components, for instance, the first component could be structured in VC-4-4c while the second component could be structured in VC-3s. Likewise, each STM-i of an STM-N (N > 1) could also be structured differently from the others. Expires January 2002 [Page 3] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 Therefore, for given TE link it is not sufficient to simply represent the total number of timeslots (i.e. the bandwidth) that are allocated. It is also essential to know the corresponding signal types. This because in SONET/SDH an ôallocatedö signal does not only consume a timeslot at a given position in the multiplex, it also imposes some restrictions on the future allocations that can be made from the free portion of the SONET/SDH multiplex. This imposes a specific Concatenation Capability rules as described in section 4.2. The types of signals that can be carried within an STS-(3*N)/STM-N (for High Order, HO) or an STS-1/STM-0 (for Low Order, LO) that are supported by the TE links are needed for path computation purposes. When computing an explicit route, a node considers the Interface Switching Capability descriptor subùTLV (see [GMPLS-RTG]) and the LS-MC sub-TLV to ensure that the path (a) has the capability to carry/switch the signal and (b) that it has sufficient available bandwidth (i.e. enough timeslot within the SONET/SDH multiplex) to carry the signal. 4. TE-Link Capabilities There are two SONET/SDH TE-link capabilities to be advertised in the routing protocols: the multiplexing capabilities and the concatenation capability. 4.1 Link Multiplex Capability The types of signals that are supported by the SONET/SDH links of a node (switch, multiplexer, or terminal) is a critical information regarding SONET/SDH network capability. Therefore this information is to be advertised via a TE routing protocol extensions. The purpose of the link multiplex capability is to succinctly describe the types of SDH/SONET signals that can be multiplexed by a node on one end of a link. For example, depending on how it is structured, an OC-48 link may be able to multiplex a variety of signal types. From a routing and path computation perspective, however, we are interested in knowing exactly which of these signals can be multiplexed at a particular end of that link in order to find an end-to-end route 4.1.1 Structure of SONET/SDH Multiplex Capabilities GMPLS-based control of SONET/SDH networks enables the control of multiplex structures at a finer level of granularity than STS-(3*N)/ STM-N (N = 1,4,16,64,256) and than STS-1/STM-0. These multiplex structures are defined in [T1.105] and [G.707]. 4.1.2 Link SONET/SDH Multiplex Capability TLV (LS-MC) The Link SONET/SDH Multiplex Capability (LS-MC) TLV describes the multiplex capabilities of either a low-order link (i.e. a single STS-1/STM-0), or a high-order link (i.e. a single STS-(3*N)/STM-N (N Expires January 2002 [Page 4] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 = 1,4,16,64,256). It indicates precisely the type of elementary signal type that can be multiplexed by this link. Both low order and high order instances of this TLV can be used simultaneously (for reasons outside of the scope of this document). In IS-IS, this TLV is a sub-TLV of the Extended IS Reachability TLV (TLV 22) with type TBD. In OSPF, this TLV is a sub-TLV of the Link TLV, with type TBD. The length of this TLV is four octets. The Multiplexing Capability Flag (MC-Flag) field is coded in one octet, and is defined as a vector of flags. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MC Flag | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF Link SONET/SDH Multiplex Capability TLV. 0 1 2 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 | MC Flag | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS Link SONET/SDH Multiplex Capability TLV. The MC Flag field above indicates the capability of a link to multiplex a given signal into the higher order signal directly above it in the SONET/SDH multiplex tree. This flag is actually a vector of bits defined separately for both High Order (HO) and for Low Order (LO) SDH/SONET signals. A bit value of 1 indicates that the multiplexing capability is supported while a bit value of 0 indicates that the multiplexing capability is not supported. Bit 1 is the lowest order bit of the flag field. The MC-Flag for HOVC SDH is: - Bit 1 : VC-3 in VC-4 (via TUG-3) - Bit 2 : VC-3 in AUG-1 - Bit 3 : VC-4-Nc in AUG-N , N=1,4,16,64 - Bit 4 : AUG-N in AUG-(4*N), N=1,4,16,64 - Bit 5 : Reserved - Bit 6 : Reserved - Bit 7 : Reserved - Bit 8 : Reserved Similarly, the MC-Flag for LOVC is: Expires January 2002 [Page 5] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 - Bit 1 : VC-11s in TUG-2 - Bit 2 : VC-12s in TUG-2 - Bit 3 : VC-2 in TUG-2 - Bit 4 : TUG-2s in TUG-3 - Bit 5 : TUG-2s in VC-3 - Bit 6 : VC-3 in STM-0 - Bit 7 : Reserved - Bit 8 : Reserved For instance, a value of HOVC MC-Flag can be: - "11111111" (0xff) indicates a full SDH HO multiplexing capability - "00001111" (0x0f) indicates that the lowest multiplexing capability is VC-3 - "00000111" (0x07) indicates a full AUG-N (within a STM-N) multiplexing capability, for a given value of N, - "00000011" (0x03) indicates a full AUG-1 (within a STM-1) multiplexing capability, For instance, a value of LOVC MC-Flag can be: - "00110010" indicates that VC-12 can only be multiplexed in VC-3 into an AU-3 (through TUG-2) and then in a STM-0. - "00110100" indicates that VC-2 can only be multiplexed in VC-3 into an AU-3 (through TUG-2) and then in a STM-0. A binary value of "00000000" should not be advertised since it indicates no SDH capability at all. Note that some values are invalid; for instance, the binary value "00011000" is invalid. The MC Flag for STS SPE in SONET is: - Bit 1 : STS-1 in STS-3c SPE - Bit 2 : STS-(3xN)c in STS-(3x(N*4))c SPE, N=1,4,16,64 - Bit 3 to 8 : reserved Similarly, the MC Flag for VT SPE is: - Bit 1 : VT-1.5 - Bit 2 : VT-2 - Bit 3 : VT-3 - Bit 4 : VT-6 - Bit 5 to 8 : reserved 4.2 Link Concatenation Capability Contiguous and Virtual concatenation of Low Order (LO) and High Order (HO) SONET and SDH signals are respectively defined in [T1.105] and [G.707]. 4.2.1 Link SONET/SDH Concatenation Capability TLV (LS-CC) Expires January 2002 [Page 6] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 The Link SONET/SDH Concatenation Capability TLV describes the SONET/SDH concatenation capabilities on a link. In IS-IS, this TLV is a sub-TLV of the Extended IS Reachability TLV with type TBD. In OSPF, this TLV is a sub-TLV of the Link TLV, with type TBD. The length is 4 or 8 octets depending on the value of the Flag V. The value is coded as follows. 1. Concatenation for SDH LOVC: - Contiguous concatenation for X VC-2s (VC-2-Xc, X = 1,...,7) - Virtual concatenation of X VC-2/1s (VC-2/1-Xv, X = 1,...,7) 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |V|E| Reserved | Max VC-2s Contiguous | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-1s Virtual | Max VC-2s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF LO Link SDH Concatenation Capability 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 | Length |V|E| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-2s Contiguous | Max VC-1s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-2s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS LO Link SDH Concatenation Capability TLV. 2. Concatenation for SDH HOVC: - Contiguous concatenation of X VC-4s (VC-4-Xc, X = 4,16,64,256) - Virtual concatenation of X VC-3/4s (VC-3/4-Xv, X = 1,...,256) 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |V|E| Reserved | Max VC-4s Contiguous | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-3s Virtual | Max VC-4s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF HO Link SDH Concatenation Capability TLVs. Expires January 2002 [Page 7] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 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 |V|E| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-4s Contiguous | Max VC-3s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-4s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS HO Link SDH Concatenation Capability TLV. Max VC-2s/VC-4s Contiguous: - this field gives the maximum number of VC-2s/VC-4s Contiguous that can be contiguously concatenated on a link. Max VC-1s/VC-3s Virtual: - this field gives the maximum number of VC-1s/VC-3s that can be virtually concatenated in one block on a link. Max VC-2s/VC-4s Virtual: - this field gives the maximum number of VC-2s/VC-4s that can be virtually concatenated on a link. A value of zero for one of these fields means that the corresponding concatenation capability is not supported. 3. Concatenation for SONET: Using the STS-1 SPE and STS-3c SPE equivalence to a VC-3 and a VC-4, respectively, the above HO Concatenation TLV applies. Notice that contiguous concatenation is applicable to STS-3c SPE signals, enabling STS-(3*X)c SPE with X = 4,16,64,256. For lower signals, Virtual Concatenation of X VT-n SPEs (n=1.5,2,3,6) is considered in [T1.105] but left for the next release of this document. 4. Support of Virtual Concatenation: Flag V Flag V, if set to 1, indicates that Virtual Concatenation is supported. Therefore, when set to 1, at least one of the (Max VC-1s or Max VC-2s) or (Max VC-3s) or (Max VC-4s) values must be non-zero. Therefore, when set to 0, this flag translates that Max VC-1s and Max VC-2s or Max VC-3s and Max VC-4s are equal to zero and so can be omitted except when Flag E would be set (see below). 4.2.2 Extended Link SONET/SDH Concatenation Capability TLV (LS-CC) In some cases equipmentÆs have limitations on the number of signal that can be concatenated. In that case, it may not possible to use a complete range of contiguous (or even virtual) concatenation. It might also be that some of supported contiguous and virtual concatenation capabilities are precluded or discarded for reasons Expires January 2002 [Page 8] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 outside of the scope of this specification. Therefore, we propose an alternate way of representing the concatenation capabilities of a link by listing explicitly all of the levels of contiguous and virtual concatenation being supported. Flag E is set to 1 to indicate the extended form of the LS-CC TLV. In that case, three lists are used to indicate all the discrete levels of concatenation supported. Each concatenation level is coded on 16 bits. The length of each list is given in terms of 16 bits entries. In IS-IS, this Extended TLV is a sub-TLV of the Extended IS Reachability TLV with type TBD. In OSPF, this TLV is a sub-TLV of the Link TLV, with type TBD. The length (in octets) is by definition variable. In below Extended LS-CC TLV examples, the first list is for the VC- 2/VC-4 contiguous concatenation, the second list is for the VC-1/VC- 3 virtual concatenation and the third list is for the VC-2/VC-4 virtual concatenation: 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |V|E| Reserved | Max VC-2s Contiguous | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-1s Virtual | Max VC-2s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Res| List 1 Length | List 2 Length | List 3 Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 1: List of VC-2s Contiguous | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 2: List of VC-1s Virtual | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 3: List of VC-2s Virtual | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF Extended LO Link SDH Concatenation 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 | Length |V|E| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-4s Contiguous | Max VC-3s Virtual | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max VC-4s Virtual | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires January 2002 [Page 9] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 |Res| List 1 Length | List 2 Length | List 3 Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 1: List of VC-4 Contiguous | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 2: List of VC-3 Virtual | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List 3: List of VC-4 Virtual | | Concatenation Levels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS Extended HO Link SDH Concatenation TLV. The reserved fields must be set to 0 when sent, and must be ignored on receipt. If no concatenation is supported on a link, this TLV should not be sent. 5. Dynamic Allocation This section defines the dynamic capabilities of a link that should be advertised by OSPF/IS-IS. The most important dynamic link capability that needs to be advertised concerns the link resources usage. In the SONET/SDH context, this information can be represented by the number of unallocated (free) timeslots per signal type and per link. 5.1 Link SONET/SDH Unallocated Timeslot TLV (LS-UT) The Link SONET/SDH Unallocated Timeslot TLV specifies the number of identical unallocated timeslots per TE-Link. As such, the initial value(s) of this TLV indicates the total capacity in terms of number of timeslot per TE-Link. In IS-IS, this TLV is a sub-TLV of the Extended IS Reachability TLV with type TBD. In OSPF, this TLV is a sub-TLV of the Link TLV, with type TBD. The length is n*4 octets. The value is the number of unallocated (free) timeslot in the TE-link, and is coded in 4 octets. The Signal Type field values are defined in [GMPLS-SONET-SDH]. Typically, a given LS-UT TLV, will only advertise signal types which are relevant for the particular implementation. Typically, a given LS-UT TLV, will only include signal types of the same order since one expect (as it is mostly the case in legacy networks) separated routing instances between LO and HOVC layers. 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 = n*4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | Expires January 2002 [Page 10] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | \\ ... \\ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF Link SONET/SDH Unallocated Timeslot 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 | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | \\ ... \\ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS Link SONET/SDH Unallocated Timeslot TLV. For instance, if a TE-link is made of 40 STM-64 decomposed in VC-4, the value of this TLV is 400 x 64. Thus, 25600 SDH STM-64 signals are supported, and, if required, 25600 instances of exactly the same signal can be allocated. Note: when two Number of Unallocated Timeslots fields having the same Signal Type value are advertised, the second one indicates the number of a contiguous block of unallocated slots. 6 Security Considerations Security considerations are not discussed in this version of the document. 7. References [G.707] ITU-T Recommendation G.707, ôNetwork Node Interface for the Synchronous Digital Hierarchyö, April 2000. [GMPLS-ARCH] E.Mannie (Editor) et al., ôGeneralized MPLS (GMPLS) Architecture,ö Internet Draft, Work in Progress, draft- ietf-ccamp-gmpls-architecture-01.txt, November 2001. [GMPLS-ISIS-TE] K. Kompella et al, ôIS-IS Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-ietf-isis-gmpls-extensions- 05.txt, January 2002. Expires January 2002 [Page 11] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 [GMPLS-OSPF-TE] K.Kompella et al., ôOSPF Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-ietf-ccamp-ospf-gmpls- extensions-04.txt, January 2002. [GMPLS-RTG] K. Kompella et al., ôRouting Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-kompella-ccamp-gmpls-routing-01.txt, February 2002. [ISIS-TE] H. Smith, T. Li, ôISIS Extensions for Traffic Engineeringö, draft-ietf-isis-traffic-04.txt, Internet Draft, Work in Progress, June 2001. [MPLS-BDL] K.Kompella et al., ôLink Bundling in MPLS Traffic Engineering,ö Internet Draft, Work in Progress, draft- ietf-mpls-bundle-01.txt, November 2001. [OSPF-TE] D. Katz, D. Yeung, K. Kompella ôTraffic Engineering Extensions to OSPFö, draft-katz-yeung-ospf-traffic- 06.txt, Internet Draft, Work in Progress, June 2001. [RFC-2370] R. Coltun, RFC 2370, "The OSPF Opaque LSA Option", July 1998. [T1.105] American National Standards Institute, ôSynchronous Optical Network (SONET) - Payload Mappingsö, ANSI T1.105, 2001. 8. Author's Addresses Eric Mannie Ebone (GTS) Terhulpsesteenweg, 6A 1560 Hoeilaart, Belgium Ph: +32-2-658.56.52 Email: eric.mannie@ebone.com Dimitri Papadimitriou Alcatel Francis Wellesplein 1, B-2018 Antwerpen, Belgium Phone: +32 3 240-8491 Email: Dimitri.Papadimitriou@alcatel.be Expires January 2002 [Page 12] draft-mannie-ccamp-gmpls-sdh-ospf-isis-01.txt FebÆ02 Expires January 2002 [Page 13]