CCAMP Working Group E. Mannie (KPNQwest) Internet Draft D. Papadimitriou (Alcatel) Expiration Date: December 2002 June 2002 GMPLS Extensions to OSPF and IS-IS for SONET/SDH Network Control draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.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 introduces 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 (aka TE Links) as defined in [MPLS-BDL]. This document proposes several new sub-TLVs for SONET/SDH network control which complement those proposed in [GMPLS-OSPF] and [GMPLS-ISIS]. The proposed encoding does not preclude any further integration in these documents that the current one intends to complement. 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. Expires December 2002 [Page 1] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 2. Introduction This document is based on Traffic Engineering (TE) extensions defined in [OSPF-TE] and [ISIS-TE]. [GMPLS-OSPF] and [GMPLS-ISIS] have extended these attributes in the GMPLS context. The proposed approach also uses the notion of 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 and identified by a TE Link ID. The set of data bearing links belonging to a given TE Link must have the same TE metric, the same set of Resource Classes and the same set of Switching Capabilities and can be advertised as a single TE Link. Such TE Links are also referred to as link bundles and their individual data bearing link (or simply links) as component links. Moreover, there is no longer a one-to-one association between a regular routing adjacency and a TE Link (see [MPLS-HIER]). In order to enable distributed SONET/SDH network control, the IGP TE routing protocol has to enable the exchange of two different sets of TE Attributes. On one hand, a set that describes the TE Link capabilities of the SONET/SDH nodeÆs interfaces, independently of their usage. On the other hand, a set that describes the resources (i.e. the SONET/SDH signals) usage on 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 the ones used for any other TE Link attribute. Therefore, when this frequency is very low the corresponding TE Link capabilities are considered as static and by opposition, the TE Link resources usage as dynamic. 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. Per [OSPF-TE], the following top-level TLVs are defined (1) Router Address (referred to as the Node TLV) and (2) TE Link TLV. When using IS-IS, GMPLS TE links are advertised using LS PDUs. TE Attributes TLVs are defined as sub-TLV for the Extended IS Reachability TLV (TLV 22) (see [ISIS-TE] and [GMPLS-ISIS]). Thus, here we propose to extend the current sub-TLV set of the TE Link TLV and Extended IS Reachability TLV, respectively. The sub- TLVs describing the capabilities of SONET/SDH TE Links are separately defined for LOVC/VT and HOVC/STS SPE; these are: - LS-MC TLV : TE Link SONET/SDH Multiplexing Capability TLV - LS-CC TLV : TE Link SONET/SDH Concatenation Capability TLV - LS-TC TLV : TE Link SONET/SDH Transparency Capability TLV Expires December 2002 [Page 2] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 The sub-TLV describing the dynamic status of the SONET/SDH TE Link components is: - LS-UT-TLV : TE Link SONET/SDH (number of) Unallocated Timeslot TLV Note: the proposed sub-TLVs can also complement the Interface Switching Capability Descriptor sub-TLV of the TE Link TLV and Extended IS Reachability TLV (see [GMPLS-OSPF] and [GMPLS-ISIS], respectively) when the Switching Capability field value refers to TDM. 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 links (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 TE Link may have the same SONET/SDH multiplexing and concatenation capabilities as defined later in this document. The two corresponding TLVs (LS-MC and LS-CC) are specified once, but apply to each component of the TE Link. Thus, no per component information or identification is required for these TLVs. The TE Link SONET/SDH Unallocated Timeslot TLV defined in Section 5 gives the total number of unallocated components (i.e. timeslots) included in a given TE Link. Combined with the Link Property Correlation (see [LMP]) of data links into TE Links (also referred to as link bundling) this capability helps in removing the potential problem of flooding huge amount 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 into the corresponding 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 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. Therefore, for given TE Link it is not sufficient to simply represent the total number of timeslots (i.e. the bandwidth) that Expires December 2002 [Page 3] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 are (un)allocated. It is also essential to know the corresponding signal types. This because in an allocated component 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 knowledge of the signal types that can be carried in an STS- (3*N)/STM-N (for High Order, HO) or an STS-1/STM-0 (for Low Order, LO) and 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 the requested signal and (b) that it has sufficient available bandwidth (i.e. enough timeslot within the SONET/SDH multiplex on each interface) to carry the requested 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 TE Link Multiplexing Capability The types of signals that are supported by the TE Links of SONET/SDH node constitute an important information with respect to the SONET/SDH network capability. Therefore this information is to be advertised via IGP TE routing protocol extensions. The purpose of the TE Link multiplexing capability is to succinctly describe the types of SONET/SDH signals that can be multiplexed by a TE Link for explicit route computation purposes. For example, depending on how it is structured, an OC-48/STM-16 link may be able to multiplex a variety of signal types. 4.1.1 Structure of SONET/SDH Multiplexing Capabilities GMPLS-based control of SONET/SDH networks enables the control of multiplex structures at a finer level of granularity than both STM- N/STS-(3xN) with N = 1, 4, 16, 64, 256 and STM-0/STS-1. These multiplexing structures are defined in [T1.105] and [G.707]. 4.1.2 TE Link SONET/SDH Multiplexing Capability TLV (LS-MC) The Link SONET/SDH Multiplexing Capability (LS-MC) TLV describes the multiplexing 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 = 1, 4, 16, 64, 256). It indicates precisely the types of elementary signal 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). Expires December 2002 [Page 4] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 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 defined as a vector of flags is coded over one octet. 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 SONET/SDH TE Link Multiplex Capability TLV 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MC Flag | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS SONET/SDH TE Link Multiplex Capability TLV The MC Flag field indicates the capability of a link to multiplex a given signal into the higher order signal in the SONET/SDH multiplex tree. This flag is a vector of bits defined separately for both High Order (HO) and for Low Order (LO) SONET/SDH 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 SDH High Order VC (HOVC) is: - Bit 1 : VC-3 in AUG-1 - Bit 2 : AUG-1 in AUG-4 - Bit 3 : AUG-4 in AUG-16 - Bit 4 : AUG-16 in AUG-64 - Bit 5 : AUG-64 in AUG-256 - Bit 6 : TUG-3 in AUG-1 (via VC-4) - Bit 7 : Reserved - Bit 8 : Reserved For instance, a value of HOVC MC-Flag can take the following values: - 0b00111111 (0x3f): indicates a full SDH HO multiplexing capability - 0b00011110 (0x1e): indicates that the lowest multiplexing capability is AUG-1 (with C4->VC4->AU4->AUG1) - 0b00000111 (0x05): indicates a full AUG-4 (within an STM-4) multiplexing capability Similarly, the MC-Flag for SDH Low Order VC (LOVC) is: Expires December 2002 [Page 5] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 - Bit 1 : VC-11 in TUG-2 - Bit 2 : VC-12 in TUG-2 - Bit 3 : Reserved - Bit 4 : VC-2 in TUG-2 - Bit 5 : TUG-2 in TUG-3 - Bit 6 : TUG-2 in VC-3 - Bit 7 : Reserved - Bit 8 : Reserved For instance, a value of LOVC MC-Flag can take the following values: - 0b00100010 (0x22): indicates that VC-12 can only be multiplexed in VC-3 (through TUG-2). - 0b00101000 (0x28): indicates that VC-2 can only be multiplexed in VC-3 (through TUG-2). Note: A binary value of 0b0..0 when advertised indicates no SDH multiplexing capability at all. Therefore referring to VC-4-Nc in AUG-N/STM-N capable interfaces only. The MC Flag for SONET high order STS SPE is: - Bit 1 : STS-1 in STSG-3 - Bit 2 : STSG-3 in STSG-12 - Bit 3 : STSG-12 in STSG-48 - Bit 4 : STSG-48 in STSG-192 - Bit 5 : STSG-192 in STSG-768 - Bit 6 to 8 : reserved Similarly, the MC Flag for SONET low order VT SPE is: - Bit 1 : VT-1.5 SPE in VT Group - Bit 2 : VT-2 SPE in VT Group - Bit 3 : VT-3 SPE in VT Group - Bit 4 : VT-6 SPE in VT Group - Bit 5 : VT-Group in STS-1 SPE - Bit 6 to 8 : reserved Note: A binary value of 0b0...0 when advertised indicates no SONET multiplexing capability at all. Therefore referring to STS3-Mc in STS-N (with N = 3xM) capable interfaces only. 4.2 TE 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]. Note: Some 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 signals for contiguous (or even virtual) concatenation. It might also be that some of the supported contiguous and virtual concatenation capabilities are precluded or Expires December 2002 [Page 6] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 discarded for reasons 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. 4.2.1 SDH TE Link Concatenation Capability TLV (LS-CC) The SDH TE Link 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 corresponding encoding and values are defined for Low Order and High Order VCs. If no concatenation is supported on a TE Link, this TLV should not be advertised. 1. Low Order VC (LOVC) Concatenation LOVC Concatenation includes: - Contiguous concatenation of X VC-2s (VC-2-Xc, X = 1,...,7) - Virtual concatenation of X VC-2/12/11s (VC-m-Xv, m = 11,12,2) as defined in the following table: Signal Carried in X interval -------------------------------------------------- VC-11-Xv VC-3 1 to 28 VC-12-Xv VC-3 1 to 21 VC-2-Xv VC-3 1 to 7 VC-11-Xv VC-4 1 to 64 VC-12-Xv VC-4 1 to 63 VC-2-Xv VC-4 1 to 21 The SDH LOVC TE Link Concatenation Capability TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // . . . // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | Expires December 2002 [Page 7] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF SDH LOVC TE Link 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // . . . // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS SDH LOVC TE Link Concatenation Capability TLV Signal Type (8 bits): The Signal Type field values are defined in [GMPLS-SONET-SDH]. CT û Concatenation Type (4 bits): The CT field is defined as a 4-bit vector of flags indicating the supported concatenation type(s): Bit 1: Contiguous Concatenation Bit 2: Virtual Concatenation Bit 3: Concatenation Conversion (see ITU-T G.783) Bit 4: Reserved Reserved (4 bits): The Reserved field bits must be set to zero when sent and should be ignored when received. LT û List Type (4 bits): The LT field indicates the type of the list; the following values are defined (the values to which they refer must be mutually disjoint): Expires December 2002 [Page 8] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 0 Inclusive list 1 Exclusive list 2 Inclusive range (one or more Minimum/Maximum pairs) 3 Exclusive range (one or more Minimum/Maximum pairs) Values ranging from 4 to 15 are reserved. List Length (12 bits): The List Length indicates the number of NCC elements included within the sub-list. Zero is an invalid value. NCC - Number of Concatenated Components (16 bits): The NCC field indicates the supported number of low order VCÆs with respect to the Signal Type and the CT values. For SDH LOVCs, the number of VC-mÆs values MUST refer to one or more of the following values (as defined in the Signal Type field): VC- 11, VC-12 and/or VC-2. When the LT field value equals 2 or 3, at least one pair of LOVCÆs numbers (i.e. two NCC fields) must be included in the list. The first value indicates the minimum number of LOVCÆs and the second one the maximum number of LOVCÆs supported (or not supported, respectively) with the selected concatenation type (CT). 2. High Order VC (HOVC) Concatenation: HOVC Concatenation includes: - 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) The SDH HOVC TE Link Concatenation Capability TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // . . . // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Expires December 2002 [Page 9] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF SDH HOVC TE 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // . . . // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | CT | Res. | LT | List Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NCC | . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS SDH HOVC TE Link SDH Concatenation Capability TLV Signal Type (8 bits): see above. CT û Concatenation Type (4 bits): see above. Reserved (4 bits): see above. LT û List Type (4 bits): see above. List Length (12 bits): see above. NCC - Number of Concatenated Components (16 bits): The NCC field indicates the supported number of high order VCÆs with respect to the Signal Type (i.e. VC-3 and/or VC-4) and the CT values. When the LT field value equals 2 or 3, at least one pair of HOVCÆs numbers (i.e. two NCC fields) must be included in the list. The first value indicates the minimum number of HOVCÆs and the second one the maximum number of HOVCÆs supported (or not supported, respectively) with the selected concatenation type (CT). Expires December 2002 [Page 10] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 4.2.2 SONET TE Link Concatenation Capability TLV (LS-CC) Using the STS-1 SPE and STS-3c SPE equivalence to a VC-3 and a VC-4, respectively, the above High Order Concatenation Capability TLV applies. Notice that in SONET, contiguous concatenation is applicable to STS-3c SPE signals, resulting in STS-(3*X)c SPE signals with X = 4, 16, 64, 256. For low order signal, only virtual concatenation of X VTn SPEs (VTn-Xv SPE, n = 1.5,2,3,6) must be considered since low order contiguous concatenation is not defined in ANSI [T1.105]. 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 corresponding encoding and values are defined for Low Order and High Order VCs. 1. Low order VT SPEs concatenation: - Virtual concatenation of X VTnÆs SPE (VTn-Xv SPE, n = 1.5,2,3, 6) as defined in the following table: Signal Carried in X interval -------------------------------------------------- VT1.5-Xv SPE STS-1 1 to 28 VT2-Xv SPE STS-1 1 to 21 VT3-Xv SPE STS-1 1 to 14 VT6-Xv SPE STS-1 1 to 7 VT1.5-Xv SPE STS-3c 1 to 64 VT2-Xv SPE STS-3c 1 to 63 VT3-Xv SPE STS-3c 1 to 42 VT6-Xv SPE STS-3c 1 to 21 The OSPF/ISIS encoding for the Low Order SONET TE Link Concatenation Capability TLV is identical to the one defined for SDH LOVC Concatenation. 2. High order STS SPEs concatenation: - Contiguous concatenation of X STS-3c SPEs (STS-(3*X)c with X = 4,16,64,256) - Virtual concatenation of X STS-1/STS-3c SPEs (STS-1-Xv/STS-3c- Xv with X = 1,...,256) The OSPF and ISIS encoding for the High Order SONET TE Link Concatenation Capability TLV is identical to the one defined for SDH HOVC Concatenation. 4.2.3 SONET/SDH TE Link Transparency Capability (LS-TC TLV) This TLV is defined as a vector of flags that indicates the type of transparency supported by each of the component of a given TE Link. Several flags can be combined to provide different types of transparency while any combination is not necessarily valid. By Expires December 2002 [Page 11] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 default, the supported transparency on a TE Link is defined as the Path Overhead (POH) transparency; therefore the LS-TC TLV should not be sent for a TE Link only supporting POH transparency. Note that when the LS-TC TLV is advertised, the Signal Type(s) field(s) in the LS-UT TLV (see Section 5) MUST take at least one of the following values (see [GMPLS-SONET-SDH]): STM-0/STS-1, STM- 1/STS-3, STM-4/STS-12, STM-16/STS-48, STM-64/STS-192, and STM- 256/STS-768. Equivalently, at least one transparency type must be specified when advertising such Signal Type(s) in the LS-UT TLV. In IS-IS, the LS-TC 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. It includes the Transparency field defined as a 32-bit 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Transparency (T) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ OSPF SONET/SDH TE Link Transparency 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Transparency (T) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS SONET/SDH TE Link Transparency Capability TLV The different transparency flags are the following: Flag 1 (bit 1): Section/Regenerator Section layer Flag 2 (bit 2): Line/Multiplex Section layer Where bit 1 is the low order bit. Others flags are reserved, they should be set to zero when sent, and should be ignored when received. A flag is set to one to indicate that the corresponding transparency is supported on the corresponding TE Link. We refer to [GMPLS-SONET-SDH-EXT] for an extended set of transparency flags beyond the standard transparencies defined in ANSI [T1.105] and ITU-T [G.707]. 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 Expires December 2002 [Page 12] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 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 (LS-UT) TLV 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 be advertised by including Signal Type(s) of the same order since one expects (as it is mostly the case in legacy networks) separated routing instances between Low Order and High Order VC transport 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Type | Number of Unallocated Timeslots | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // . . . // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IS-IS Link SONET/SDH Unallocated Timeslot TLV Expires December 2002 [Page 13] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 For instance, if a TE Link is constituted by 40 STM-64, each of them decomposed in VC-4, initially the value of the Number of Unallocated Timeslots field of this TLV is 40 x 64. Thus, 2560 VC-4 signals are supported, and, if required, 2560 instances of exactly the same signal can be allocated. When two Number of Unallocated Timeslots fields with the same Signal Type value are advertised, the second one indicates the number of contiguous block of unallocated timeslots. Thus, when advertised initially the corresponding value equal 1. 6 Security Considerations This document does not introduce additional considerations to [OSPF- TE] and [ISIS-TE]. 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-02.txt, February 2002. [GMPLS-ISIS] K.Kompella et al, ôIS-IS Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-ietf-isis-gmpls-extensions-13.txt, June 2002. [GMPLS-OSPF] K.Kompella et al., ôOSPF Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-ietf-ccamp-ospf-gmpls-extensions-07.txt, April 2002. [GMPLS-RTG] K.Kompella et al., ôRouting Extensions in Support of Generalized MPLS,ö Internet Draft, Work in Progress, draft-ietf-ccamp-gmpls-routing-04.txt, April 2002. [GMPLS-SONET-SDH] E.Mannie and D.Papadimitriou (Editors) et al., "GMPLS extensions for SONET and SDH control", Internet Draft, Work in progress, draft-ietf-ccamp-gmpls-sonet- sdh-05.txt, May 2002. [ISIS-TE] H.Smith and 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-03.txt, May 2002. Expires December 2002 [Page 14] draft-mannie-ccamp-gmpls-sonet-sdh-ospf-isis-01.txt JuneÆ02 [MPLS-HIER] K.Kompella and Y.Rekhter, ôLSP Hierarchy with Generalized MPLS TEö, Internet Draft, Work in progress, draft-ietf-mpls-lsp-hierarchy-06.txt, May 2002. [OSPF-TE] D.Katz, D.Yeung and K.Kompella, ôTraffic Engineering Extensions to OSPFö, draft-katz-yeung-ospf-traffic- 06.txt, Internet Draft, Work in Progress, October 2001. [RFC-2370] R.Coltun, RFC 2370, Standard Track, "The OSPF Opaque LSA Option", July 1998. [T1.105] American National Standards Institute, ôSynchronous Optical Network - Payload Mappingsö, ANSI T1.105, 2001. 8. Author's Addresses Eric Mannie (KPNQwest) Dimitri Papadimitriou (Alcatel) Terhulpsesteenweg, 6A Francis Wellesplein 1, 1560 Hoeilaart, Belgium B-2018 Antwerpen, Belgium Phone:+32 2 658-5652 Phone:+32 3 240-8491 Email: eric.mannie@ebone.com Email:dimitri.papadimitriou@alcatel.be Expires December 2002 [Page 15]