Network Working Group Greg Bernstein Internet Draft Grotto Networking Intended status: Standards Track Young Lee Expires: August 2008 Dan Li Huawei Wataru Imajuku NTT February 20, 2008 Routing and Wavelength Assignment Information for Wavelength Switched Optical Networks draft-bernstein-ccamp-wson-info-02.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 This Internet-Draft will expire on August 20, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract Bernstein and Lee Expires August 20, 2008 [Page 1] Internet-Draft Wavelength Switched Optical Networks February 2008 This memo provides and information model and compact encodings for information needed for path computation and wavelength assignment in wavelength switched optical networks. Such encodings can be used in extensions to Generalized Multi-Protocol Label Switching (GMPLS) routing for control of wavelength switched optical networks (WSON) or for other mechanisms, e.g. XML based, for conveying this information to a path computation element. 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]. Table of Contents 1. Introduction...................................................3 2. Terminology....................................................3 3. High Level Information Model...................................4 3.1. Information Model.........................................4 3.2. Node Information..........................................5 3.2.1. ConnectivityMatrix...................................5 3.2.2. OEOWavelengthConverterInfo...........................6 3.3. Link Information..........................................6 3.3.1. Port Wavelength Restrictions.........................7 3.4. Dynamic Link Information..................................7 3.5. Dynamic Node Information..................................8 3.6. End System Information....................................8 4. Application to OSPF GMPLS extensions...........................8 4.1. Node Top Level TLV........................................8 4.2. Link Sub-TLVs.............................................9 4.3. Dealing with Dynamic Information..........................9 5. Type Length Value (TLV) Encoding of WSON Information...........9 5.1. Wavelength Information Encoding..........................10 5.2. Link Set Sub-TLV.........................................10 5.3. Wavelength Set Sub-TLV...................................12 5.3.1. Inclusive/Exclusive Wavelength Lists................13 5.3.2. Inclusive/Exclusive Wavelength Ranges...............14 5.3.3. Bitmap Wavelength Set...............................14 5.4. Connectivity Matrix Sub-TLV..............................15 5.5. Port Wavelength Restriction sub-TLV......................19 6. Security Considerations.......................................20 7. IANA Considerations...........................................20 8. Acknowledgments...............................................20 9. References....................................................21 Bernstein and Lee Expires August 20, 2008 [Page 2] Internet-Draft Wavelength Switched Optical Networks February 2008 9.1. Normative References.....................................21 9.2. Informative References...................................21 10. Contributors.................................................22 Author's Addresses...............................................22 Intellectual Property Statement..................................23 Disclaimer of Validity...........................................24 1. Introduction This document provides an information model and efficient encodings of information needed by the routing and wavelength assignment (RWA) process in wavelength switched optical networks (WSONs). Such encodings can be to extend GMPLS IGPs. In addition these encodings or information could be used by other mechanisms to convey this same information to a path computation element (PCE). Note since these encodings are relatively efficient they can provide more accurate analysis of the control plane communications/processing load for WSONs looking to utilize a GMPLS control plane. 2. Terminology CWDM: Coarse Wavelength Division Multiplexing. DWDM: Dense Wavelength Division Multiplexing. FOADM: Fixed Optical Add/Drop Multiplexer. ROADM: Reconfigurable Optical Add/Drop Multiplexer. A reduced port count wavelength selective switching element featuring ingress and egress line side ports as well as add/drop side ports. RWA: Routing and Wavelength Assignment. Wavelength Conversion/Converters: The process of converting an information bearing optical signal centered at a given wavelength to one with "equivalent" content centered at a different wavelength. Wavelength conversion can be implemented via an optical-electronic- optical (OEO) process or via a strictly optical process. WDM: Wavelength Division Multiplexing. Wavelength Switched Optical Networks (WSON): WDM based optical networks in which switching is performed selectively based on the center wavelength of an optical signal. Bernstein and Lee Expires August 20, 2008 [Page 3] Internet-Draft Wavelength Switched Optical Networks February 2008 3. High Level Information Model The purpose of the following information model and encodings for WSONs is to facilitate constrained lightpath computation. In particular, the cases of no or a limited number of wavelength converters available in the WSON. This constraint is frequently referred to as the "wavelength continuity" constraint, and the corresponding constrained lightpath computation is known as the routing and wavelength assignment (RWA) problem. Hence the information model must provide sufficient topology and wavelength restriction and availability information to support this computation. More details on the RWA process and WSON subsystems and their properties can be found in [WSON-Frame]. 3.1. Information Model From [WSON-Frame] the following WSON information needs to be conveyed via GMPLS routing or some other mechanism. Information Static/Dynamic --------------------------------------------------------- Connectivity matrix Static Per port wavelength restrictions Static(2) WDM link (fiber) lambda ranges Static(2) WDM link channel spacing Static(2) Laser Transmitter range Static(2) Wavelength conversion capabilities Static(2) Wavelength Availability Dynamic(2) Wavelength Converter availability Dynamic(1,2) Notes: 1. This could be dynamic in the case of a limited pool of converters where the number available can change with connection establishment. Note we may want to include regeneration capabilities here since OEO converters are also regenerators. 2. Not necessarily needed in the case of distributed wavelength assignment via signaling. See [WSON-Frame] for more details on these types of WSON information and their use. For the purposes of conveying the information we can group the information model into four categories regardless of whether they stem from a switching subsystem or a line subsystem: o Node Information Bernstein and Lee Expires August 20, 2008 [Page 4] Internet-Draft Wavelength Switched Optical Networks February 2008 o Link Information o Dynamic Node Information o Dynamic Link Information o End System Information In the following we use a BNF/Regular expression like syntax where the symbol "|" indicates a choice between two or more elements; the symbol "*" indicates zero or more occurrences of an element; the symbol "?" indicates zero or one occurrences; and the symbol "+" indicates one or more occurrences. 3.2. Node Information Node information contains relatively static information related to a WSON node. This includes internal information such as a connectivity matrix and port wavelength constraints. Additional information could include properties of wavelength converters in the node if any are present. Formally, Node Information := Node_ID (ConnectivityMatrix?, OEOWavelengthConverterInfo? ) Where the Node_ID would be a "Router ID" in OSPFv2. 3.2.1. ConnectivityMatrix The ConnectivityMatrix represents the potential connectivity matrix for asymmetric switches (e.g. ROADMs and such) and the connectivity matrix for asymmetric fixed devices. The following provides a compact representation of the connectivity via a list of pairs of link sets that have connectivity to each other. ConnectivityMatrix := ConnectivityFixed (LinkSetA, LinkSetB)+ Where ConnectivityFixed is a Boolean that takes the value true if the device has fixed connectivity and false if the device is a switch or ROADM. LinkSets are defined in Section 5.2. Only two valid combinations of link sets A and B are permitted. In the first case LinkSetA is a set of ingress links and LinkSetB is a set of egress links. In the second case LinkSetA and LinkSetB are both bi- directional link sets. Bernstein and Lee Expires August 20, 2008 [Page 5] Internet-Draft Wavelength Switched Optical Networks February 2008 3.2.2. OEOWavelengthConverterInfo An OEO based wavelength converter can be characterized by an input wavelength set and an output wavelength set. In addition any constraints on the signal formats and rates accommodated by the converter must be described. Such a wavelength converter can be modeled by: OEOWavelengthConverterInfo := RegeneratorLevel (IngressWavelengthRange, EgressWavelengthRange, BitRateRange?, AcceptableSignals? ) Where the RegeneratorLevel is used to model an OEO regenerator. Regenerators are usually classified into three levels. Level 1 provides signal amplification, level 2 amplification and pulse shaping, and level 3 amplification, pulse shaping and timing regeneration. Level 2 regenerators can have a restricted bit rate range, while level 3 regenerators can also be specialized to a particular signal type. For ingress and egress wavelength ranges see the WavelengthSet definition in section 5.3. 3.3. Link Information WSONs contribute information in addition to that in RFC3630 (OSPF-TE) and RFC4203 (OSPF for GMPLS) via additional link constraints. These stem from (a) WDM line system characterization, laser transmitter tuning restrictions, and switching subsystem port wavelength constraints, e.g., colored ROADM drop ports. As described below we add two new sub-elements to the link information model derived from [RFC3630, RFC4203]: (a) the maximum number of channels, and (b) link wavelength restrictions. Note that network topology information is implicit in the link information element. LinkInfo := LocalLinkID LocalNodeID RemoteLinkID RemoteNodeID (AdministrativeGroup?, InterfaceCapDesc?, MaximumBandwidthPerChannel?, Protection?, SRLG*, TrafficEngineeringMetric?, PortWavelengthRestriction?) Note that RFC3630 provides other ways to identify local and remote link ends in the case of numbered links. In the above we have reinterpreted the Maximum Bandwidth of RFC3630 as the maximum bandwidth per WDM channel and have omitted the Maximum Reservable Bandwidth of RFC3630 since overbooking is not typically used in circuit switching for obvious reasons. In addition we propose an alternative to the Unreserved Bandwidth of RFC3630 in the next section. Bernstein and Lee Expires August 20, 2008 [Page 6] Internet-Draft Wavelength Switched Optical Networks February 2008 3.3.1. Port Wavelength Restrictions Models the wavelength restrictions that various optical devices such as OXC, ROADMs, and waveband mulitplers may impose on a port. PortWavelengthRestriction := (RestrictionKind, MaxNumChannels, WavelengthSet ) Where RestrictionKind can take the following values and meanings: 0 Simple wavelength selective restriction. Max number of channels indicates the number of wavelength permitted on the port and the accompanying wavelength set indicates the permitted values. 1 Waveband device with a tunable center frequency and passband. In this case the maximum number of channels indicates the maximum width of the waveband in terms of the channels spacing given in the wavelength set. The corresponding wavelength set is used to indicate the overall tuning range. Specific center frequency tuning information can be obtained from dynamic channel in use information. It is assumed that both center frequency and bandwidth (Q) tuning can be done without causing faults in existing signals. A 16 bit non-negative integer would suffice for the maximum number of channels. For example if the port is a "colored" drop port of a ROADM then the value of RestrictionKind = 0 for a simple wavelength selective restriction, the MaxNumberOfChannels = 1, and the wavelength restriction is just a wavelength set consisting of a single member corresponding to the frequency of the permitted wavelength. 3.4. Dynamic Link Information By dynamic information we mean information that is subject to change on a link with subsequent connection establishment or teardown. Currently for WSON the only information we currently envision is wavelength availability. DynamicLinkInfo := LocalLinkID LocalNodeID RemoteLinkID RemoteNodeID AvailableWavelengths Where, once again, the local and remote link and node IDs are used to specify the particular link in the unnumbered case and AvailableWavelengths is a WavelengthSet as defined in Section 5.3. Bernstein and Lee Expires August 20, 2008 [Page 7] Internet-Draft Wavelength Switched Optical Networks February 2008 3.5. Dynamic Node Information Dynamic node information is used to hold information for a node that can change frequently. Currently only wavelength converter availability information is included as a possible (but not required) information sub-element. DynamicNodeInfo := NodeID AvailableWavelengthConverters? Where NodeID is a node identifier such as the router ID in OSPFv2 and the number of currently available wavelength converters is given by AvailableWavelengthConverters. 3.6. End System Information Current end system information of interest includes the tuning range of laser transmitters, support or single or multiple wavelengths on a port, etc... 4. Application to OSPF GMPLS extensions RFC2370 defined the opaque link state advertisement (LSA) and its various flavors based on flooding scope. RFC3630 defines the Traffic Engineering (TE) LSA which is an opaque LSA of area flooding scope with an LSA ID defined by: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | Instance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ "The Instance field is an arbitrary value used to maintain multiple Traffic Engineering LSAs. A maximum of 16777216 Traffic Engineering LSAs may be sourced by a single system. The LSA ID has no topological significance." [RFC3630] From RFC3630 the TE LSA can contain only one top level TLV and RFC3630 defines two top level TLVs: (a) router address, and (b) link. RFC4203 adds new sub-TLVs to the top level link TLV to support GMPLS, but does not add any new top level TLVs. 4.1. Node Top Level TLV As we saw in section 3.2. for WSON networks there can be a significant amount of information specific to nodes in WSON networks hence we recommend the addition of a new top level TE TLV (e.g. type Bernstein and Lee Expires August 20, 2008 [Page 8] Internet-Draft Wavelength Switched Optical Networks February 2008 5) for holding node related information. Currently we have defined two sub-TLVs for the Node TLV: (a) Connectivity Matrix sub-TLV, (b) OEO Wavelength converter information sub-TLV. 4.2. Link Sub-TLVs As discussed in section 3.3. two new sub-TLVs are needed to characterize WSON links: (a) Maximum number of channels sub-TLV and, (b) wavelength constraints sub-TLV. 4.3. Dealing with Dynamic Information In our information model we differentiated between relatively static and dynamic information; defining dynamic information as that information that is subject to change due to connection setup or teardown. There are three ways that we could differentiate dynamic from static information in flooding and processing, if desired. A. Use a separate TE LSA instance for static and dynamic information for the same modeled entity. For example, one could group all the relatively static information concerning a specific link into one instance and the wavelength availability information (subTLV of the link TLV) into another TE LSA instance. B. Use separate top level TLVs to differentiate static and dynamic information. For example define a top level "dynamic link" TLV. C. Define a new "dynamic TE LSA" type (e.g. opaque type 5) specifically for conveying dynamic information These three different options are ordered in reverse of the amount of processing required to tell whether the information is dynamic or not. For example in case (A) one must look all the way into the sub- TLV type to understand that this is dynamic information, while in case (C) this can easily be inferred from the LSA ID. Note that for high level LSA processing the LSA ID is the finest granularity field that would be looked at. 5. Type Length Value (TLV) Encoding of WSON Information A TLV encoding of the high level WSON information model is given in the following sections. This encoding is designed to be suitable for use in routing protocols such as OSPFv2 via the extension mechanisms of RFC2370 (opaque LSA), RFC3630 (OSPF-TE) and RFC4203 (OSPF-GMPLS), and in PCE protocols such as PCEP. Note that the information in Bernstein and Lee Expires August 20, 2008 [Page 9] Internet-Draft Wavelength Switched Optical Networks February 2008 RFC3630 and RFC4203 is arranged via the nesting of sub-TLVs within TLVs and we will make use of such constructs. The following encodings have multiple uses in specifying WSON information. 5.1. Wavelength Information Encoding This document makes frequent use of the lambda label format defined in [Otani] shown below: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where Grid is used to indicate which ITU-T grid specification is being used. C.S. = Channel spacing used in a DWDM system, i.e., with a ITU-T G.694.1 grid. S = sign of the offset from the center frequency of 193.1THz for the ITU-T 6.694.1 grid. n = Used to specify the frequency as 193.1THz +/- n*(channel spacing) where the + or - is chosen based on the sign (S) bit. 5.2. Link Set Sub-TLV We will frequently want to describe properties of links. To do so efficiently we can make use of a link set concept similar to the label set concept of [RFC3471]. All links will be denoted by their local link identifier as defined an used in[RFC4202, RFC4203, RFC4205]. The information carried in a Link Set is defined by: Bernstein and Lee Expires August 20, 2008 [Page 10] Internet-Draft Wavelength Switched Optical Networks February 2008 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action |Dir| Format | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Identifier 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : : : : : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Identifier N | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Action: 8 bits 0 - Inclusive List Indicates that the object/TLV contains one or more link elements that are included in the Link Set. 1 - Exclusive List Indicates that the object/TLV contains one or more link elements that are excluded from the Link Set. 2 - Inclusive Range Indicates that the object/TLV contains a range of links. The object/TLV contains two link 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. 3 - Exclusive Range Indicates that the object/TLV contains a range of links that are excluded from the Link Set. The object/TLV contains two link 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. Dir: Directionality of the Link Set (2 bits) 0 -- bidirectional 1 -- ingress Bernstein and Lee Expires August 20, 2008 [Page 11] Internet-Draft Wavelength Switched Optical Networks February 2008 2 -- egress In optical networks we think in terms of unidirectional as well as bidirectional links. For example wavelength restrictions or connectivity may be much different for an ingress port, than for its "companion" egress port if it has one. Note that "interfaces" such as discussed in the Interfaces MIB are assumed bidirectional, as well as the links of various link state IGPs. Format: The format of the link identifier (6 bits) 0 -- Link Local Identifier Others TBD. Reserved: 16 bits This field is reserved. It MUST be set to zero on transmission and MUST be ignored on receipt. Link Identifier: The link identifier represents the port which is being described either for connectivity or wavelength restrictions. This can be the link local identifier of [RFC4202], GMPLS routing, [RFC4203] GMPLS OSPF routing, and [RFC4205] IS-IS GMPLS routing. The use of the link local identifier format can result in more compact WSON encodings when the assignments are done in a reasonable fashion. 5.3. Wavelength Set Sub-TLV Wavelength sets come up frequently in WSONs to describe the range of a laser transmitter, the wavelength restrictions on ROADM ports, or the availability of wavelengths on a DWDM link. The general format for a wavelength set is given below. This format uses the Action concept from [RFC3471] with an additional Action to define a "bit map" type of label set. Note that the second 32 bit field is a lambda label in the previously defined format. This provides important information on the WDM grid type and channel spacing that will be used in the compact encodings listed. Bernstein and Lee Expires August 20, 2008 [Page 12] Internet-Draft Wavelength Switched Optical Networks February 2008 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action | Reserved | Num Wavelengths | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Additional fields as necessary per action | | Action: 0 - Inclusive List 1 - Exclusive List 2 - Inclusive Range 3 - Exclusive Range 4 - Bitmap Set 5.3.1. Inclusive/Exclusive Wavelength Lists In the case of the inclusive/exclusive lists the wavelength set format is given by: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Action=0 or 1 | Reserved | Num Wavelengths | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n2 | n3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | nm | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where Num Wavelengths tells us the number of wavelength in this inclusive or exclusive list this does not include the initial wavelength in the list hence if the number of wavelengths is odd then zero padding of the last half word is required. Bernstein and Lee Expires August 20, 2008 [Page 13] Internet-Draft Wavelength Switched Optical Networks February 2008 5.3.2. Inclusive/Exclusive Wavelength Ranges In the case of inclusive/exclusive ranges the wavelength set format is given by: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Action=2 or 3 | Reserved | Num Wavelengths | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ In this case Num Wavelengths specifies the number of wavelengths in the range starting at the given wavelength and incrementing the Num Wavelengths number of channel spacing up in frequency (regardless of the value of the sign bit). 5.3.3. Bitmap Wavelength Set In the case of Action = the bitmap the wavelength set format is given by: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action = 4 | Reserved | Num Wavelengths | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Bit Map Word #1 (Lowest frequency channels) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Bit Map Word #N (Highest frequency channels) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where Num Wavelengths in this case tells us the number of wavelengths represented by the bit map which is required to be ceiling[(Num Wavelengths)/32]. Each bit in the bit map represents a particular frequency with a value of 1/0 indicating whether the frequency is in the set or not. Bit position zero represents the lowest frequency, while each succeeding bit position represents the next frequency a channel spacing (C.S.) above the previous. Example: Bernstein and Lee Expires August 20, 2008 [Page 14] Internet-Draft Wavelength Switched Optical Networks February 2008 A 40 channel C-Band DWDM system with 100GHz spacing with lowest frequency 192.0THz (1561.4nm) and highest frequency 195.9THz (1530.3nm). These frequencies correspond to n = -11, and n = 28 respectively. Now suppose the following channels are available: Frequency(THz) n Value bit map position -------------------------------------------------- 192.0 -11 0 192.5 -6 5 193.1 0 11 193.9 8 19 194.0 9 20 195.2 21 32 195.8 27 38 With the Grid value set to indicate an ITU-T G.694.1 DWDM grid, C.S. set to indicate 100GHz, and with S (sign) set to indicate negative this lambda bit map set would then be encoded as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action = 4 | Reserved | Num Wavelengths = 40 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency = -11 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1 0 0 0 0 0 1 0| Not used in 40 Channel system (all zeros) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.4. Connectivity Matrix Sub-TLV The potential connectivity matrix for asymmetric switches (e.g. ROADMs and such) and the connectivity matrix for asymmetric fixed devices can be represented by a matrix A where Amn = 0 or 1, depending upon whether a wavelength on ingress port m can be connected to egress port n. This can be compactly represented link sets as follows: Bernstein and Lee Expires August 20, 2008 [Page 15] Internet-Draft Wavelength Switched Optical Networks February 2008 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Connectivity | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Set A #1 | : : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Set B #1 : : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Additional Link set pairs as needed | : to specify connectivity : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where Connectivity = 0 if the device is fixed 1 if the device is reconfigurable (ROADM/OXC) Issue for further study: It may be useful to have a bit from the reserved field to indicate whether "local" switching can take place or not, i.e., whether the diagonal of Amn should be assumed to be 0 or 1 in cases where the same port # appears in both ingress set list and egress set list. For a typical ROADM Amm = 0. Example: Suppose we have a typical 2-degree 40 channel ROADM. In addition to its two line side ports it has 80 add and 80 drop ports. The picture below illustrates how a typical 2-degree ROADM system that works with bi-directional fiber pairs is a highly asymmetrical system composed of two unidirectional ROADM subsystems. Bernstein and Lee Expires August 20, 2008 [Page 16] Internet-Draft Wavelength Switched Optical Networks February 2008 (Tributary) Ports #3-#42 Ingress added to Egress dropped from West Line Egress East Line Ingress vvvv ^^^^ | |...| | |...| +-----| |...|--------| |...|------+ | +----------------------+ | | | | | Egress | | Unidirectional ROADM | | -----------------+ | | +-------------- <=====================| |===================< -----------------+ +----------------------+ +-------------- | | Port #1 | | Port #2 (West Line Side) | |(East Line Side) -----------------+ +----------------------+ +-------------- >=====================| |===================> -----------------+ | Unidirectional ROADM | +-------------- | | | | | | _ | | | +----------------------+ | +-----| |...|--------| |...|------+ | |...| | |...| vvvv ^^^^ (Tributary) Ports #43-#82 Egress dropped from Ingress added to West Line ingress East Line egress Referring to the figure we see that the ingress direction of ports #3-#42 (add ports) can only potentially egress on port #1. While in ingress side of port #2 (line side) can egress only on ports #3-#42 (drop) and #1 (pass through). Similarly, the ingress direction of ports #43-#82 can only potentially egress on port #2 (line). While the ingress direction of port #1 can only potentially egress on ports #43-#82 (drop) or port #2 (pass through). We can now represent this potential connectivity matrix as follows. This representation uses only 30 32-bit words. Bernstein and Lee Expires August 20, 2008 [Page 17] Internet-Draft Wavelength Switched Optical Networks February 2008 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Conn = 1 | Reserved |1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: adds to line +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=2 |0 1|0 0 0 0 0 0|Reserved(Note:inclusive range) |2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #3 |3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #42 |4 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |1 0|0 0 0 0 0 0|Reserved (Note:inclusive list) |5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #1 |6 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: line to drops +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #2 |8 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=2 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|9 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #3 |10 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #42 |11 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: line to line +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |12 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #2 |13 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|14 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #1 |15 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: adds to line +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=2 |0 1|0 0 0 0 0 0|Reserved(Note:inclusive range) |16 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #42 |17 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #82 |18 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Bernstein and Lee Expires August 20, 2008 [Page 18] Internet-Draft Wavelength Switched Optical Networks February 2008 | Action=0 |1 0|0 0 0 0 0 0|Reserved (Note:inclusive list) |19 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #2 |20 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: line to drops +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |21 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #1 |22 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=2 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|23 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #43 |24 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #82 |25 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Note: line to line +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |26 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #1 |27 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Action=0 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|28 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Identifier = #2 |30 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.5. Port Wavelength Restriction sub-TLV The port wavelength restriction of section 3.3.1. can be encoded as a sub-TLV as follows. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |RestrictionKind| Reserved | MaxNumChannels | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ --Wavelength Set-- | Action | Reserved | Num Wavelengths | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S. |S| Reserved | n for lowest frequency | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Additional fields as necessary per action | | | Where the meanings of RestrictionKind, MaxNumChannels and the Wavelength Set were defined in section 3.3.1. Bernstein and Lee Expires August 20, 2008 [Page 19] Internet-Draft Wavelength Switched Optical Networks February 2008 6. Security Considerations This document has no requirement for a change to the security models within GMPLS and associated protocols. That is the OSPF-TE, RSVP-TE, and PCEP security models could be operated unchanged. 7. IANA Considerations TBD. Once finalized in our approach we will need identifiers for such things and modulation types, modulation parameters, wavelength assignment methods, etc... 8. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. Bernstein and Lee Expires August 20, 2008 [Page 20] Internet-Draft Wavelength Switched Optical Networks February 2008 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM applications: DWDM frequency grid", June, 2002. [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, September 2003. [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, October 2005 [RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005. 9.2. Informative References [Otani] T. Otani, H. Guo, K. Miyazaki, D. Caviglia, "Generalized Labels of Lambda-Switching Capable Label Switching Routers (LSR)", work in progress: draft-otani-ccamp-gmpls-lambda- labels-01.txt, November 2007. [G.694.1] ITU-T Recommendation G.694.1, Spectral grids for WDM applications: DWDM frequency grid, June 2002. [G.694.2] ITU-T Recommendation G.694.2, Spectral grids for WDM applications: CWDM wavelength grid, December 2003. [RFC4205] Kompella, K., Ed., and Y. Rekhter, Ed., "Intermediate System to Intermediate System (IS-IS) Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4205, October 2005. Bernstein and Lee Expires August 20, 2008 [Page 21] Internet-Draft Wavelength Switched Optical Networks February 2008 [WSON-Frame] G. Bernstein, Y. Lee, W. Imajuku, "Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks", work in progress: draft-bernstein-ccamp-wavelength- switched-02.txt, February 2008. 10. Contributors Diego Caviglia Ericsson Via A. Negrone 1/A 16153 Genoa Italy Phone: +39 010 600 3736 Email: diego.caviglia@(marconi.com, ericsson.com) Anders Gavler Acreo AB Electrum 236 SE - 164 40 Kista Sweden Email: Anders.Gavler@acreo.se Jonas Martensson Acreo AB Electrum 236 SE - 164 40 Kista, Sweden Email: Jonas.Martensson@acreo.se Itaru Nishioka NEC Corp. 1753 Simonumabe, Nakahara-ku, Kawasaki, Kanagawa 211-8666 Japan Phone: +81 44 396 3287 Email: i-nishioka@cb.jp.nec.com Author's Addresses Greg Bernstein (ed.) Grotto Networking Fremont, CA, USA Phone: (510) 573-2237 Email: gregb@grotto-networking.com Bernstein and Lee Expires August 20, 2008 [Page 22] Internet-Draft Wavelength Switched Optical Networks February 2008 Young Lee (ed.) Huawei Technologies 1700 Alma Drive, Suite 100 Plano, TX 75075 USA Phone: (972) 509-5599 (x2240) Email: ylee@huawei.com Dan Li Huawei Technologies Co., Ltd. F3-5-B R&D Center, Huawei Base, Bantian, Longgang District Shenzhen 518129 P.R.China Phone: +86-755-28973237 Email: danli@huawei.com Wataru Imajuku NTT Network Innovation Labs 1-1 Hikari-no-oka, Yokosuka, Kanagawa Japan Phone: +81-(46) 859-4315 Email: imajuku.wataru@lab.ntt.co.jp Intellectual Property Statement 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. Bernstein and Lee Expires August 20, 2008 [Page 23] Internet-Draft Wavelength Switched Optical Networks February 2008 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. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST 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. Copyright Statement Copyright (C) The IETF Trust (2008). 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Bernstein and Lee Expires August 20, 2008 [Page 24]