Network Working Group L. Berger, Editor Request for Comments: 3471 Movaz Networks Category: Standards Track January 2003 Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved.
AbstractThis document describes extensions to Multi-Protocol Label Switching (MPLS) signaling required to support Generalized MPLS. Generalized MPLS extends the MPLS control plane to encompass time-division (e.g., Synchronous Optical Network and Synchronous Digital Hierarchy, SONET/SDH), wavelength (optical lambdas) and spatial switching (e.g., incoming port or fiber to outgoing port or fiber). This document presents a functional description of the extensions. Protocol specific formats and mechanisms, and technology specific details are specified in separate documents. 1. Introduction ............................................... 2 2. Overview .................................................. 3 3. Label Related Formats ..................................... 6 3.1 Generalized Label Request ............................... 6 3.2 Generalized Label ....................................... 11 3.3 Waveband Switching ...................................... 12 3.4 Suggested Label ......................................... 13 3.5 Label Set ............................................... 14 4. Bidirectional LSPs ......................................... 16 4.1 Required Information .................................... 17 4.2 Contention Resolution ................................... 17 5. Notification on Label Error ................................ 20 6. Explicit Label Control ..................................... 20 6.1 Required Information .................................... 21
7. Protection Information ..................................... 21 7.1 Required Information .................................... 22 8. Administrative Status Information .......................... 23 8.1 Required Information .................................... 24 9. Control Channel Separation ................................. 25 9.1 Interface Identification ................................ 25 9.2 Fault Handling .......................................... 27 10. Acknowledgments ............................................ 27 11. Security Considerations .................................... 28 12. IANA Considerations ........................................ 28 13. Intellectual Property Considerations ....................... 29 14. References ................................................. 29 14.1 Normative References ................................... 29 14.2 Informative References ................................. 30 15. Contributors ............................................... 31 16. Editor's Address ........................................... 33 17. Full Copyright Statement ................................... 34 RFC3031] has been defined to support the forwarding of data based on a label. In this architecture, Label Switching Routers (LSRs) were assumed to have a forwarding plane that is capable of (a) recognizing either packet or cell boundaries, and (b) being able to process either packet headers (for LSRs capable of recognizing packet boundaries) or cell headers (for LSRs capable of recognizing cell boundaries). The original architecture has recently been extended to include LSRs whose forwarding plane recognizes neither packet, nor cell boundaries, and therefore, can't forward data based on the information carried in either packet or cell headers. Specifically, such LSRs include devices where the forwarding decision is based on time slots, wavelengths, or physical ports. Given the above, LSRs, or more precisely interfaces on LSRs, can be subdivided into the following classes: 1. Interfaces that recognize packet/cell boundaries and can forward data based on the content of the packet/cell header. Examples include interfaces on routers that forward data based on the content of the "shim" header, interfaces on (Asynchronous Transfer Mode) ATM-LSRs that forward data based on the ATM VPI/VCI. Such interfaces are referred to as Packet-Switch Capable (PSC).
2. Interfaces that forward data based on the data's time slot in a repeating cycle. An example of such an interface is an interface on a SONET/SDH Cross-Connect. Such interfaces are referred to as Time-Division Multiplex Capable (TDM). 3. Interfaces that forward data based on the wavelength on which the data is received. An example of such an interface is an interface on an Optical Cross-Connect that can operate at the level of an individual wavelength. Such interfaces are referred to as Lambda Switch Capable (LSC). 4. Interfaces that forward data based on a position of the data in the real world physical spaces. An example of such an interface is an interface on an Optical Cross-Connect that can operate at the level of a single (or multiple) fibers. Such interfaces are referred to as Fiber-Switch Capable (FSC). Using the concept of nested Label Switched Paths (LSPs) allows the system to scale by building a forwarding hierarchy. At the top of this hierarchy are FSC interfaces, followed by LSC interfaces, followed by TDM interfaces, followed by PSC interfaces. This way, an LSP that starts and ends on a PSC interface can be nested (together with other LSPs) into an LSP that starts and ends on a TDM interface. This LSP, in turn, can be nested (together with other LSPs) into an LSP that starts and ends on an LSC interface, which in turn can be nested (together with other LSPs) into an LSP that starts and ends on a FSC interface. See [MPLS-HIERARCHY] for more information on LSP hierarchies. The establishment of LSPs that span only the first class of interfaces is defined in [RFC3036, RFC3212, RFC3209]. This document presents a functional description of the extensions needed to generalize the MPLS control plane to support each of the four classes of interfaces. Only signaling protocol independent formats and definitions are provided in this document. Protocol specific formats are defined in [RFC3473] and [RFC3472]. Technology specific details are outside the scope of this document and will be specified in technology specific documents, such as [GMPLS-SONET]. 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 [RFC2119].
types of switching has driven generalized MPLS to extend certain base functions of traditional MPLS and, in some cases, to add functionality. These changes and additions impact basic LSP properties, how labels are requested and communicated, the unidirectional nature of LSPs, how errors are propagated, and information provided for synchronizing the ingress and egress. In traditional MPLS Traffic Engineering, links traversed by an LSP can include an intermix of links with heterogeneous label encodings. For example, an LSP may span links between routers, links between routers and ATM-LSRs, and links between ATM-LSRs. Generalized MPLS extends this by including links where the label is encoded as a time slot, or a wavelength, or a position in the real world physical space. Just like with traditional MPLS TE, where not all LSRs are capable of recognizing (IP) packet boundaries (e.g., an ATM-LSR) in their forwarding plane, generalized MPLS includes support for LSRs that can't recognize (IP) packet boundaries in their forwarding plane. In traditional MPLS TE an LSP that carries IP has to start and end on a router. Generalized MPLS extends this by requiring an LSP to start and end on similar type of LSRs. Also, in generalized MPLS the type of a payload that can be carried by an LSP is extended to allow such payloads as SONET/SDH, or 1 or 10Gb Ethernet. These changes from traditional MPLS are reflected in how labels are requested and communicated in generalized MPLS, see Sections 3.1 and 3.2. A special case of Lambda switching, called Waveband switching is also described in Section 3.3. Another basic difference between traditional and non-PSC types of generalized MPLS LSPs, is that bandwidth allocation for an LSP can be performed only in discrete units, see Section 3.1.3. There are also likely to be (much) fewer labels on non-PSC links than on PSC links. Note that the use of Forwarding Adjacencies (FA), see [MPLS- HIERARCHY], provides a mechanism that may improve bandwidth utilization, when bandwidth allocation can be performed only in discrete units, as well as a mechanism to aggregate forwarding state, thus allowing the number of required labels to be reduced. Generalized MPLS allows for a label to be suggested by an upstream node, see Section 3.4. This suggestion may be overridden by a downstream node but, in some cases, at the cost of higher LSP setup time. The suggested label is valuable when establishing LSPs through certain kinds of optical equipment where there may be a lengthy (in electrical terms) delay in configuring the switching fabric. For example micro mirrors may have to be elevated or moved, and this physical motion and subsequent damping takes time. If the labels and hence switching fabric are configured in the reverse direction (the
norm) the MAPPING/Resv message may need to be delayed by 10's of milliseconds per hop in order to establish a usable forwarding path. The suggested label is also valuable when recovering from nodal faults. Generalized MPLS extends on the notion of restricting the range of labels that may be selected by a downstream node, see Section 3.5. In generalized MPLS, an ingress or other upstream node may restrict the labels that may be used by an LSP along either a single hop or along the whole LSP path. This feature is driven from the optical domain where there are cases where wavelengths used by the path must be restricted either to a small subset of possible wavelengths, or to one specific wavelength. This requirement occurs because some equipment may only be able to generate a small set of the wavelengths that intermediate equipment may be able to switch, or because intermediate equipment may not be able to switch a wavelength at all, being only able to redirect it to a different fiber. While traditional traffic engineered MPLS (and even LDP) are unidirectional, generalized MPLS supports the establishment of bidirectional LSPs, see Section 4. The need for bidirectional LSPs comes from non-PSC applications. There are multiple reasons why such LSPs are needed, particularly possible resource contention when allocating reciprocal LSPs via separate signaling sessions, and simplifying failure restoration procedures in the non-PSC case. Bidirectional LSPs also have the benefit of lower setup latency and lower number of messages required during setup. Generalized MPLS supports the communication of a specific label to use on a specific interface, see Section 6. [RFC3473] also supports an RSVP specific mechanism for rapid failure notification. Generalized MPLS formalizes possible separation of control and data channels, see Section 9. Such support is particularly important to support technologies where control traffic cannot be sent in-band with the data traffic. Generalized MPLS also allows for the inclusion of technology specific parameters in signaling. The intent is for all technology specific parameters to be carried, when using RSVP, in the SENDER_TSPEC and other related objects, and when using CR-LDP, in the Traffic Parameters TLV. Technology specific formats will be defined on an as needed basis. For an example definition, see [GMPLS-SONET].
Switching Type: 8 bits Indicates the type of switching that should be performed on a particular link. This field is needed for links that advertise more than one type of switching capability. This field should map to one of the values advertised for the corresponding link in the routing Switching Capability Descriptor, see [GMPLS- RTG]. The following are currently defined values: Value Type ----- ---- 1 Packet-Switch Capable-1 (PSC-1) 2 Packet-Switch Capable-2 (PSC-2) 3 Packet-Switch Capable-3 (PSC-3) 4 Packet-Switch Capable-4 (PSC-4) 51 Layer-2 Switch Capable (L2SC) 100 Time-Division-Multiplex Capable (TDM) 150 Lambda-Switch Capable (LSC) 200 Fiber-Switch Capable (FSC)
Generalized PID (G-PID): 16 bits An identifier of the payload carried by an LSP, i.e., an identifier of the client layer of that LSP. This is used by the nodes at the endpoints of the LSP, and in some cases by the penultimate hop. Standard Ethertype values are used for packet and Ethernet LSPs; other values are: Value Type Technology ----- ---- ---------- 0 Unknown All 1 Reserved 2 Reserved 3 Reserved 4 Reserved 5 Asynchronous mapping of E4 SDH 6 Asynchronous mapping of DS3/T3 SDH 7 Asynchronous mapping of E3 SDH 8 Bit synchronous mapping of E3 SDH 9 Byte synchronous mapping of E3 SDH 10 Asynchronous mapping of DS2/T2 SDH 11 Bit synchronous mapping of DS2/T2 SDH 12 Reserved 13 Asynchronous mapping of E1 SDH 14 Byte synchronous mapping of E1 SDH 15 Byte synchronous mapping of 31 * DS0 SDH 16 Asynchronous mapping of DS1/T1 SDH 17 Bit synchronous mapping of DS1/T1 SDH 18 Byte synchronous mapping of DS1/T1 SDH 19 VC-11 in VC-12 SDH 20 Reserved 21 Reserved 22 DS1 SF Asynchronous SONET 23 DS1 ESF Asynchronous SONET 24 DS3 M23 Asynchronous SONET 25 DS3 C-Bit Parity Asynchronous SONET 26 VT/LOVC SDH 27 STS SPE/HOVC SDH 28 POS - No Scrambling, 16 bit CRC SDH 29 POS - No Scrambling, 32 bit CRC SDH 30 POS - Scrambling, 16 bit CRC SDH 31 POS - Scrambling, 32 bit CRC SDH 32 ATM mapping SDH 33 Ethernet SDH, Lambda, Fiber 34 SONET/SDH Lambda, Fiber 35 Reserved (SONET deprecated) Lambda, Fiber 36 Digital Wrapper Lambda, Fiber 37 Lambda Fiber
38 ANSI/ETSI PDH SDH 39 Reserved SDH 40 Link Access Protocol SDH SDH (LAPS - X.85 and X.86) 41 FDDI SDH, Lambda, Fiber 42 DQDB (ETSI ETS 300 216) SDH 43 FiberChannel-3 (Services) FiberChannel 44 HDLC SDH 45 Ethernet V2/DIX (only) SDH, Lambda, Fiber 46 Ethernet 802.3 (only) SDH, Lambda, Fiber RFC3473] and [RFC3472]. Signal Type (Bit-rate) Value (Bytes/Sec) (IEEE Floating point) -------------- --------------- --------------------- DS0 (0.064 Mbps) 0x45FA0000 DS1 (1.544 Mbps) 0x483C7A00 E1 (2.048 Mbps) 0x487A0000 DS2 (6.312 Mbps) 0x4940A080 E2 (8.448 Mbps) 0x4980E800 Ethernet (10.00 Mbps) 0x49989680 E3 (34.368 Mbps) 0x4A831A80 DS3 (44.736 Mbps) 0x4AAAA780 STS-1 (51.84 Mbps) 0x4AC5C100 Fast Ethernet (100.00 Mbps) 0x4B3EBC20 E4 (139.264 Mbps) 0x4B84D000 FC-0 133M 0x4B7DAD68 OC-3/STM-1 (155.52 Mbps) 0x4B9450C0 FC-0 266M 0x4BFDAD68 FC-0 531M 0x4C7D3356 OC-12/STM-4 (622.08 Mbps) 0x4C9450C0 GigE (1000.00 Mbps) 0x4CEE6B28 FC-0 1062M 0x4CFD3356 OC-48/STM-16 (2488.32 Mbps) 0x4D9450C0 OC-192/STM-64 (9953.28 Mbps) 0x4E9450C0 10GigE-LAN (10000.00 Mbps) 0x4E9502F9 OC-768/STM-256 (39813.12 Mbps) 0x4F9450C0
MPLS- HIERARCHY]. Each Generalized Label object/TLV carries a variable length label parameter. MPLS-BUNDLE] is being used.
The information carried in a Port and Wavelength label 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Label: 32 bits Indicates port/fiber or lambda to be used, from the perspective of the sender of the object/TLV. Values used in this field only have significance between two neighbors, and the receiver may need to convert the received value into a value that has local significance. Values may be configured or dynamically determined using a protocol such as [LMP].
section 3.2.1. In the context of waveband switching, the generalized label 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Waveband Id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Start Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | End Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Waveband Id: 32 bits A waveband identifier. The value is selected by the sender and reused in all subsequent related messages. Start Label: 32 bits Indicates the channel identifier of the lowest value wavelength making up the waveband, from the object/TLV sender's perspective. End Label: 32 bits Indicates the channel identifier of the highest value wavelength making up the waveband, from the object/TLV sender's perspective. Channel identifiers are established either by configuration or by means of a protocol such as LMP [LMP]. They are normally used in the label parameter of the Generalized Label one PSC and LSC.
setup latency, and may be important for restoration purposes where alternate LSPs may need to be rapidly established as a result of network failures. The use of Suggested Label is only an optimization. If a downstream node passes a different label upstream, an upstream LSR reconfigures itself so that it uses the label specified by the downstream node, thereby maintaining the downstream control of a label. Note, the transmission of a suggested label does not imply that the suggested label is available for use. In particular, an ingress node should not transmit data traffic on a suggested label until the downstream node passes a label upstream. The information carried in a suggested label is identical to a generalized label. Note, values used in the label field of a suggested label are from the object/TLV sender's perspective.
3 - Exclusive Range Indicates that the object/TLV contains a range of labels that are excluded from the Label Set. The object/TLV contains two subchannel elements. The first element indicates the start of the range. The second element indicates the end of the range. A value of zero indicates that there is no bound on the corresponding portion of the range. Reserved: 10 bits This field is reserved. It MUST be set to zero on transmission and MUST be ignored on receipt. Label Type: 14 bits Indicates the type and format of the labels carried in the object/TLV. Values are signaling protocol specific. Subchannel: The subchannel represents the label (wavelength, fiber ... ) which is eligible for allocation. This field has the same format as described for labels under section 3.2. Note that subchannel to local channel identifiers (e.g., wavelength) mappings are a local matter. RFC3209] or [RFC3212] two unidirectional paths must be independently established. This approach has the following disadvantages: * The latency to establish the bidirectional LSP is equal to one round trip signaling time plus one initiator-terminator signaling transit delay. This not only extends the setup latency for successful LSP establishment, but it extends the worst-case
latency for discovering an unsuccessful LSP to as much as two times the initiator-terminator transit delay. These delays are particularly significant for LSPs that are established for restoration purposes. * The control overhead is twice that of a unidirectional LSP. This is because separate control messages (e.g., Path and Resv) must be generated for both segments of the bidirectional LSP. * Because the resources are established in separate segments, route selection is complicated. There is also additional potential race for conditions in assignment of resources, which decreases the overall probability of successfully establishing the bidirectional connection. * It is more difficult to provide a clean interface for SONET/SDH equipment that may rely on bidirectional hop-by-hop paths for protection switching. * Bidirectional optical LSPs (or lightpaths) are seen as a requirement for many optical networking service providers. With bidirectional LSPs both the downstream and upstream data paths, i.e., from initiator to terminator and terminator to initiator, they are established using a single set of signaling messages. This reduces the setup latency to essentially one initiator-terminator round trip time plus processing time, and limits the control overhead to the same number of messages as a unidirectional LSP. Section 3.2.
means. To resolve contention, the node with the higher node ID will win the contention and it MUST issue a PathErr/NOTIFICATION message with a "Routing problem/Label allocation failure" indication. Upon receipt of such an error, the node SHOULD try to allocate a different Upstream label (and a different Suggested Label if used) to the bidirectional path. However, if no other resources are available, the node must proceed with standard error handling. To reduce the probability of contention, one may impose a policy that the node with the lower ID never suggests a label in the downstream direction and always accepts a Suggested Label from an upstream node with a higher ID. Furthermore, since the labels may be exchanged using LMP, an alternative local policy could further be imposed such that (with respect to the higher numbered node's label set) the higher numbered node could allocate labels from the high end of the label range while the lower numbered node allocates labels from the low end of the label range. This mechanism would augment any close packing algorithms that may be used for bandwidth (or wavelength) optimization. One special case that should be noted when using RSVP and supporting this approach is that the neighbor's node ID might not be known when sending an initial Path message. When this case occurs, a node should suggest a label chosen at random from the available label space. An example of contention between two nodes (PXC 1 and PXC 2) is shown in Figure 1. In this example PXC 1 assigns an Upstream Label for the channel corresponding to local BCId=2 (local BCId=7 on PXC 2) and sends a Suggested Label for the channel corresponding to local BCId=1 (local BCId=6 on PXC 2). Simultaneously, PXC 2 assigns an Upstream Label for the channel corresponding to its local BCId=6 (local BCId=1 on PXC 1) and sends a Suggested Label for the channel corresponding to its local BCId=7 (local BCId=2 on PXC 1). If there is no restriction on the labels that can be used for bidirectional LSPs and if there are alternate resources available, then both PXC 1 and PXC 2 will pass different labels upstream and the contention is resolved naturally (see Fig. 2). However, if there is a restriction on the labels that can be used for bidirectional LSPs (for example, if they must be physically coupled on a single I/O card), then the contention must be resolved using the node ID (see Fig. 3).
+------------+ +------------+ + PXC 1 + + PXC 2 + + + SL1,UL2 + + + 1 +------------------------>+ 6 + + + UL1, SL2 + + + 2 +<------------------------+ 7 + + + + + + + + + + 3 +------------------------>+ 8 + + + + + + 4 +<------------------------+ 9 + +------------+ +------------+ Figure 1. Label Contention In this example, PXC 1 assigns an Upstream Label using BCId=2 (BCId=7 on PXC 2) and a Suggested Label using BCId=1 (BCId=6 on PXC 2). Simultaneously, PXC 2 assigns an Upstream Label using BCId=6 (BCId=1 on PXC 1) and a Suggested Label using BCId=7 (BCId=2 on PXC 1). +------------+ +------------+ + PXC 1 + + PXC 2 + + + UL2 + + + 1 +------------------------>+ 6 + + + UL1 + + + 2 +<------------------------+ 7 + + + + + + + L1 + + + 3 +------------------------>+ 8 + + + L2 + + + 4 +<------------------------+ 9 + +------------+ +------------+ Figure 2. Label Contention Resolution without resource restrictions
In this example, there is no restriction on the labels that can be used by the bidirectional connection and there is no contention. +------------+ +------------+ + PXC 1 + + PXC 2 + + + UL2 + + + 1 +------------------------>+ 6 + + + L2 + + + 2 +<------------------------+ 7 + + + + + + + L1 + + + 3 +------------------------>+ 8 + + + UL1 + + + 4 +<------------------------+ 9 + +------------+ +------------+ Figure 3. Label Contention Resolution with resource restrictions In this example, labels 1,2 and 3,4 on PXC 1 (labels 6,7 and 8,9 on PXC 2, respectively) must be used by the same bidirectional connection. Since PXC 2 has a higher node ID, it wins the contention and PXC 1 must use a different set of labels. RFC3209], [RFC3472] and [RFC3473]. When these cases occur, it can be useful for the node generating the error message to indicate which labels would be acceptable. To cover this case, GMPLS introduces the ability to convey such information via the "Acceptable Label Set". An Acceptable Label Set is carried in appropriate protocol specific error messages, see [RFC3472] and [RFC3473]. The format of an Acceptable Label Set is identical to a Label Set, see section 3.5.1.
label used on a link. Specifically, the problem is that ERO and ER- Hop do not support explicit label sub-objects. An example case where such a mechanism is desirable is where there are two LSPs to be "spliced" together, i.e., where the tail of the first LSP would be "spliced" into the head of the second LSP. This last case is more likely to be used in the non-PSC classes of links. To cover this case, the Label ERO subobject / ER Hop is introduced. Section 3.2.1. Placement and ordering of these parameters are signaling protocol specific. GMPLS-RTG]. Path computation algorithms may take this information into account when computing paths for setting up LSPs. Protection Information also indicates if the LSP is a primary or secondary LSP. A secondary LSP is a backup to a primary LSP. The resources of a secondary LSP are not used until the primary LSP
fails. The resources allocated for a secondary LSP MAY be used by other LSPs until the primary LSP fails over to the secondary LSP. At that point, any LSP that is using the resources for the secondary LSP MUST be preempted.
0x10 Dedicated 1+1 Indicates that a dedicated link layer protection scheme, i.e., 1+1 protection, should be used to support the LSP. 0x08 Dedicated 1:1 Indicates that a dedicated link layer protection scheme, i.e., 1:1 protection, should be used to support the LSP. 0x04 Shared Indicates that a shared link layer protection scheme, such as 1:N protection, should be used to support the LSP. 0x02 Unprotected Indicates that the LSP should not use any link layer protection. 0x01 Extra Traffic Indicates that the LSP should use links that are protecting other (primary) traffic. Such LSPs may be preempted when the links carrying the (primary) traffic being protected fail.
MPLS-BUNDLE]. In GMPLS, the separation of control and data channel may be due to any number of factors. (Including bundling and other cases such as data channels that cannot carry in- band control information.) This section will cover the two critical related issues: the identification of data channels in signaling and handling of control channel failures that don't impact data channels. LMP]). In all cases the choice of the data interface is indicated by the upstream node using addresses and identifiers used by the upstream node.
Where each 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Value ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Length: 16 bits Indicates the total length of the TLV, i.e., 4 + the length of the value field in octets. A value field whose length is not a multiple of four MUST be zero-padded so that the TLV is four- octet aligned. Type: 16 bits Indicates type of interface being identified. Defined values are: Type Length Format Description -------------------------------------------------------------------- 1 8 IPv4 Addr. IPv4 2 20 IPv6 Addr. IPv6 3 12 See below IF_INDEX (Interface Index) 4 12 See below COMPONENT_IF_DOWNSTREAM (Component interface) 5 12 See below COMPONENT_IF_UPSTREAM (Component interface) For types 3, 4 and 5 the Value field has the 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ IP Address: 32 bits The IP address field may carry either an IP address of a link or an IP address associated with the router, where associated address is the value carried in a router address TLV of routing.
Interface ID: 32 bits For type 3 usage, the Interface ID carries an interface identifier. For types 4 and 5, the Interface ID indicates a bundled component link. The special value 0xFFFFFFFF can be used to indicate the same label is to be valid across all component links. RFC3473] and [RFC3472]. Note that these cases only apply when there are mechanisms to detect data channel failures independent of control channel failures.
RFC3212] or [RFC3209]. The security considerations mentioned in [RFC3212] or [RFC3209] apply to the respective protocol specific forms of GMPLS, see [RFC3473] and [RFC3472]. BCP 26 "Guidelines for Writing an IANA Considerations Section in RFCs" [BCP26]. This document defines the following namespaces: o LSP Encoding Type: 8 bits o Switching Type: 8 bits o Generalized PID (G-PID): 16 bits o Action: 8 bits o Interface_ID Type: 16 bits All future assignments should be allocated through IETF Consensus action or documented in a Specification. LSP Encoding Type - valid value range is 1-255. This document defines values 1-11. Switching Type - valid value range is 1-255. This document defines values 1-4, 100, 150 and 200. Generalized PID (G-PID) - valid value range is 0-1500. This document defines values 0-46. Action - valid value range is 0-255. This document defines values 0-3. Interface_ID Type - valid value range is 1-65535. This document defines values 1-5.
Section 10.4 of [RFC2026]. The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels," BCP 14, RFC 2119, March 1997. [RFC3036] Andersson, L., Doolan, P., Feldman, N., Fredette, A. and B. Thomas, "LDP Specification", RFC 3036, January 2001. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V. and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3212] Jamoussi, B., Andersson, L., Callon, R., Dantu, R., Wu, L., Doolan, P., Worster, T., Feldman, N., Fredette, A., Girish, M., Gray, E., Heinanen, J., Kilty, T. and A. Malis, "Constraint-Based LSP Setup using LDP", RFC 3212, January 2002.
[RFC3472] Ashwood-Smith, P. and L. Berger, Editors, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling - Constraint-based Routed Label Distribution Protocol (CR-LDP) Extensions", RFC 3472, January 2003. [RFC3473] Berger, L., Editor "Generalized Multi-Protocol Label Switching (GMPLS) Signaling - Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [GMPLS-RTG] Kompella, K., et al., "Routing Extensions in Support of Generalized MPLS", Work in Progress. [GMPLS-SONET] Ashwood-Smith, P., et al., "GMPLS - SONET / SDH Specifics", Work in Progress. [LMP] Lang, et al., "Link Management Protocol", Work in Progress. [MPLS-BUNDLE] Kompella, K., Rekhter, Y. and L. Berger, "Link Bundling in MPLS Traffic Engineering", Work in Progress. [MPLS-HIERARCHY] Kompella, K. and Y. Rekhter, "LSP Hierarchy with MPLS TE", Work in Progress. [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 3," BCP 9, RFC 2026, October 1996. [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. [RFC3031] Rosen, E., Viswanathan, A. and R. Callon, "Multiprotocol label switching Architecture", RFC 3031, January 2001.
Yanhe Fan Axiowave Networks, Inc. 200 Nickerson Road Marlborough, MA 01752 Phone: + 1 774 348 4627 EMail: firstname.lastname@example.org Kireeti Kompella Juniper Networks, Inc. 1194 N. Mathilda Ave. Sunnyvale, CA 94089 EMail: email@example.com Jonathan P. Lang EMail: firstname.lastname@example.org Eric Mannie Independent Consultant 2 Avenue de la Folle Chanson 1050 Brussels Belgium EMail: email@example.com Bala Rajagopalan Tellium, Inc. 2 Crescent Place P.O. Box 901 Oceanport, NJ 07757-0901 Phone: +1 732 923 4237 Fax: +1 732 923 9804 EMail: firstname.lastname@example.org Yakov Rekhter Juniper Networks, Inc. EMail: email@example.com
Debanjan Saha EMail: firstname.lastname@example.org Vishal Sharma Metanoia, Inc. 1600 Villa Street, Unit 352 Mountain View, CA 94041-1174 Phone: +1 650-386-6723 EMail: email@example.com George Swallow Cisco Systems, Inc. 250 Apollo Drive Chelmsford, MA 01824 Phone: +1 978 244 8143 EMail: firstname.lastname@example.org Z. Bo Tang EMail: email@example.com
Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society.