INTERNET DRAFT Tomohiro Otani Updates: RFC 3471 KDDI Intended status: standard track (Editor) Expires: September 23, 2009 March 23, 2009 Generalized Labels for G.694 Lambda-Switching Capable Label Switching Routers Document: draft-ietf-ccamp-gmpls-g-694-lambda-labels-04.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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 September 23, 2009. Abstract Technology in the optical domain is constantly evolving and as a consequence new equipment providing lambda switching capability has been developed and is currently being deployed. However, RFC 3471 has defined that a wavelength label (section 3.2.1.1) "only has significance between two neighbors" and global wavelength continuity is not considered. In order to achieve interoperability in a network composed of next generation lambda switch-capable equipment, this document defines a standard lambda label format, being compliant with ITU-T G.694. Moreover some consideration on how to ensure lambda continuity with RSVP-TE is provided. This document is a companion to the Generalized Multi-Protocol Label Switching (GMPLS) signaling. It defines the label format when Lambda Switching is requested in an all optical network. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 1]
Internet Drafts March 2009 Table of Contents Abstract........................................................... 1 1. Introduction.................................................... 2 2. Conventions used in this document............................... 2 3. Assumed network model and related problem statement............. 2 4. Label Related Formats........................................... 5 5. Security Considerations......................................... 8 6. IANA Considerations............................................. 9 7. Acknowledgement................................................ 10 8. References..................................................... 11 8.1. Normative References......................................... 11 8.2. Informative References....................................... 11 Appendix A. DWDM Example.......................................... 11 Appendix B. CWDM Example.......................................... 12 Authors' address.................................................. 13 Intellectual property and Copyright Statement..................... 14 1. Introduction As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS from supporting only packet (Packet Switching Capable - PSC) interfaces and switching to also include support for four new classes of interfaces and switching: o Layer-2 Switch Capable (L2SC) o Time-Division Multiplex (TDM) o Lambda Switch Capable (LSC) o Fiber-Switch Capable (FSC). A functional description of the extensions to MPLS signaling needed to support new classes of interfaces and switching is provided in [RFC3471]. This document presents details that are specific to the use of GMPLS with a new generation of Lambda Switch Capable (LSC) equipment. Technologies such as Reconfigurable Optical Add/Drop Multiplex (ROADM) and Wavelength Cross-Connect (WXC) operate at the wavelength switching level. As such, the wavelength is important information that is necessary to set up a wavelength-based LSP appropriately and the wavelength defined in [G.694] is widely utilized. 2. 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]. 3. Assumed network model and related problem statement T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 2]
Internet Drafts March 2009 Figure 1 depicts an all-optically switched network consisting of different vendor's optical network domains. Vendor A's network consists of ROADM or WXC, and vendor B's network consists of PXCs and DWDMs, otherwise both vendors' networks might be based on the same technology. In this case, the use of standardized wavelength label information is quite significant to establish a wavelength-based LSP. It is also an important constraint when conducting CSPF calculation for RSVP-TE signaling. The way the CSPF is performed is outside the scope of this document, but defined in [GMPLS-CSPF]. It is needless to say, a LSP must be appropriately provisioned between a selected pair of ports not only within Domain A but also over multiple domains satisfying wavelength constraints. Figure 2 illustrates in detail the interconnection between Domain A and Domain B. | Domain A (or Vendor A) | Domain B (or Vendor B) | Node-1 Node-2 | Node-6 Node-7 +--------+ +--------+ | +-------+ +-+ +-+ +-------+ | ROADM | | ROADM +---|------+ PXC +-+D| |D+-+ PXC | | or WXC +========+ or WXC +---|------+ +-+W+=====+W+-+ | | (LSC) | | (LSC) +---|------+ (LSC) +-+D| |D+-+ (LSC) | +--------+ +--------+ | | +-|M| |M+-+ | || || | +++++++++ +-+ +-+ +++++++++ || Node-3 || | ||||||| ||||||| || +--------+ || | +++++++++ +++++++++ ||===| WXC +===|| | | DWDM | | DWDM | | (LSC) | | +--++---+ +--++---+ ||===+ +===|| | || || || +--------+ || | +--++---+ +--++---+ || || | | DWDM | | DWDM | +--------+ +--------+ | +++++++++ +++++++++ | ROADM | | ROADM | | ||||||| ||||||| | or WXC +========+ or WXC +=+ | +-+ +++++++++ +-+ +-+ +++++++++ | (LSC) | | (LSC) | | | |D|-| PXC +-+D| |D+-+ PXC | +--------+ +--------+ +=|==+W|-| +-+W+=====+W+-+ | Node-4 Node-5 | |D|-| (LSC) +-+D| |D+-+ (LSC) | | |M|-| +-+M| |M+-+ | | +-+ +-------+ +-+ +-+ +-------+ | Node-8 Node-9 Figure 1 Wavelength-based network model. +-------------------------------------------------------------+ | Domain A | Domain B | T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 3]
Internet Drafts March 2009 | | | | +---+ lambda 1 | +---+ | | | |---------------|---------| | | | WDM | N | lambda 2 | | N | WDM | | =====| O |---------------|---------| O |===== | | O | D | . | | D | O | | T WDM | E | . | | E | WDM T | | H =====| 2 | lambda n | | 6 |===== H | | E | |---------------|---------| | E | | R +---+ | +---+ R | | | | | N +---+ | +---+ N | | O | | | | | O | | D WDM | N | | | N | WDM D | | E =====| O | WDM | | O |===== E | | S | D |=========================| D | S | | WDM | E | | | E | WDM | | =====| 5 | | | 8 |===== | | | | | | | | | +---+ | +---+ | +-------------------------------------------------------------+ Figure 2 Interconnecting details between two domains. In the scenario of Figure 1, consider the setting up of a bidirectional LSP from ingress switch 1 to egress switch 9. In order to satisfy wavelength continuity constraint, a fixed wavelength (lambda 1) needs to be used in domain A and domain B. A Path message will be used for the signaling, the PATH message must contain the upstream label and a label set object; both containing the same lambda. The label set object is made by only one sub channel that must be same as the upstream label. The path setup will continue downstream to switch 9 by configuring each lambda switch based on the wavelength label. This label allows the correct switching of lambda switches and the label contents needs to be used over the inter- domain. As same above, the path setup will continue downstream to switch 9 by configuring lambda switch based on multiple wavelength labels. If the node has a tunable wavelength transponder, the tuning wavelength is considered as a part of wavelength switching operation. Not using a standardized label would add undue burden on the operator to enforce policy as each manufacturer may decide on a different representation and therefore each domain may have its own label formats. Moreover, manual provisioning may lead to misconfiguration if domain-specific labels are used. Therefore, a wavelength label should be standardized in order to allow interoperability between multiple domains; otherwise appropriate existing labels are identified in support of wavelength availability. As identical wavelength information, the ITU-T frequency grid specified in [G.694.1] for Dense WDM (DWDM) and wavelength information in [G.694.2] for Coarse WDM (CWDM) are used by LSRs and should be followed as a wavelength label. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 4]
Internet Drafts March 2009 4. Label Related Formats To deal with the widening scope of MPLS into the optical and time domains, several new forms of "label" have been defined in [RFC3471]. This section contains clarifications for the Wavelength label based on [G.694] and Label Set definition specific for LSC LSRs. 4.1 Wavelength Labels In section 3.2.1.1 of [RFC3471], a Wavelength label is defined to have significance between two neighbors, and the receiver may need to convert the received value into a value that has local significance. LSC equipment uses multiple wavelengths controlled by a single control channel. In such case, the label indicates the wavelength to be used for the LSP. This document proposes to standardize the wavelength label. As an example of wavelength values, the reader is referred to [G.694.1] which lists the frequencies from the ITU-T DWDM frequency grid. The same can be done for CWDM technology by using the wavelength defined in [G.694.2]. In that sense, we can call G.694 wavelength labels. Since the ITU-T DWDM grid is based on nominal central frequencies, we need to indicate the appropriate table, the channel spacing in the grid and a value n that allows the calculation of the frequency. That value can be positive or negative. The frequency is calculated as such in [G.694.1]: Frequency (THz) = 193.1 THz + n * channel spacing (THz) , where n is a two's-complement integer (positive, negative or 0) and channel spacing is defined to be 0.0125, 0.025, 0.05 or 0.1 THz. When wider channel spacing such as 0.2 THz is utilized, the combination of narrower channel spacing and the value n can provide proper frequency with that channel spacing. Channel spacing is not utilized to indicate the LSR capability but only to specify a frequency in signaling. For the other example of the case of the ITU-T CWDM grid, the spacing between different channels was defined to be 20nm, so we need to pass the wavelength value in nm in this case. Examples of CWDM wavelengths are 1471, 1491, etc. nm. The wavelength is calculated as follows Wavelength (nm) = 1471 nm + n * 20 nm , where n is a two's-complement integer (positive, negative or 0).The tables listed in [G.694.1] and [G.694.2] are not numbered and change with the changing frequency spacing as technology advances, so an index is not appropriate in this case. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 5]
Internet Drafts March 2009 4.2 DWDM Wavelength Label For the case of DWDM, the information carried in a 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S | Reserved | n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (1) Grid: 3 bits The value for grid is set to 1 for ITU-T DWDM Grid as defined in [G.694.1]. +----------+---------+ | Grid | Value | +----------+---------+ | Reserved | 0 | +----------+---------+ |ITU-T DWDM| 1 | +----------+---------+ |ITU-T CWDM| 2 | +----------+---------+ |Future use| 3 - 7 | +----------+---------+ (2) C.S.(channel spacing): 4 bits DWDM channel spacing is defined as follows. +----------+---------+ | C.S(GHz) | Value | +----------+---------+ | Reserved | 0 | +----------+---------+ | 100 | 1 | +----------+---------+ | 50 | 2 | +----------+---------+ | 25 | 3 | +----------+---------+ | 12.5 | 4 | +----------+---------+ |Future use| 5 - 15 | +----------+---------+ (3) n: 16 bits n is a two's-complement integer to take either a negative, zero or a positive value. The value used to compute the frequency as shown above. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 6]
Internet Drafts March 2009 4.3 CWDM Wavelength Label For the case of CWDM, the information carried in a 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Grid | C.S | Reserved | n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The structure of the label in the case of CWDM is the same as that of DWDM case. (1) Grid: 3 bits The value for grid is set to 2 for ITU-T CWDM Grid as defined in [G.694.2]. +----------+---------+ | Grid | Value | +----------+---------+ | Reserved | 0 | +----------+---------+ |ITU-T DWDM| 1 | +----------+---------+ |ITU-T CWDM| 2 | +----------+---------+ |Future use| 3 - 7 | +----------+---------+ (2) C.S.(channel spacing): 4 bits CWDM channel spacing is defined as follows. +----------+---------+ | C.S(nm) | Value | +----------+---------+ | Reserved | 0 | +----------+---------+ | 20 | 1 | +----------+---------+ |Future use| 2 - 15 | +----------+---------+ (3) n: 16 bits n is a two's-complement integer. The value used to compute the wavelength as shown above. We do not need to define a new type as the information stored is either a port label or a wavelength label. Only the wavelength label as above needs to be defined. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 7]
Internet Drafts March 2009 5. Security Considerations This document introduces no new security considerations to [RFC3473]. GMPLS security is described in section 11 of [RFC3471] and refers to [RFC3209] for RSVP-TE. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 8]
Internet Drafts March 2009 6. IANA Considerations This document has no actions for IANA. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 9]
Internet Drafts March 2009 7. Acknowledgement The authors would like to thank Adrian Farrel, Lawrence Mao, Zafar Ali, Dan Li and Daniele Ceccarelli for the discussion and their comments. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 10]
Internet Drafts March 2009 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [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. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (MPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (MPLS) Signaling - Resource ReserVation Protocol Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3945] Mannie, E., Ed., "Generalized Multiprotocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. 8.2. Informative References [GMPLS-CSPF] Otani, T., et al, "Considering Generalized Multiprotocol Label Switching Traffic Engineering Attributes During Path Computation", draft-otani-ccamp-gmpls-cspf-constraints-08.txt, Feb. 2008. [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. Appendix A. DWDM Example Considering the network displayed in figure 1 it is possible to show an example of LSP set up using the lambda labels. Node 1 receives the request for establishing an LSP from itself to Node 9. The ITU-T grid to be used is the DWDM one, the channel spacing is 50Ghz and the wavelength to be used is 193,35 THz. Node 1 signals the LSP via a Path message including a Wavelength Label structured as defined in section 4.2: 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 | Reserved | n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 11]
Internet Drafts March 2009 Where: Grid = 1 : ITU-T DWDM grid C.S. = 2 : 50 GHz channel spacing n = 5 : Frequency (THz) = 193.1 THz + n * channel spacing (THz) 193.35 (THz) = 193.1 (THz) + n* 0.05 (THz) n = (193.35-193.1)/0.05 = 5 Appendix B. CWDM Example The network displayed in figure 1 can be used also to display an example of signaling using the Wavelength Label in a CWDM environment. This time the signaling of an LSP from Node 4 to Node 7 is considered. Such LSP exploits the CWDM ITU-T grid with a 20nm channel spacing and is to established using wavelength equal to 1331 nm. Node 4 signals the LSP via a Path message including a Wavelength Label structured as defined in section 4.3: 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 | Reserved | n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: Grid = 2 : ITU-T CWDM grid C.S. = 1 : 20 nm channel spacing n = -7 : Wavelength (nm) = 1471 nm + n * 20 nm 1331 (nm) = 1471 (nm) + n * 20 nm n = (1331-1471)/20 = -7 T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 12]
Internet Drafts March 2009 Authors' address Tomohiro Otani KDDI Corporation 2-3-2 Nishishinjuku Shinjuku-ku Tokyo, 163-8003, Japan Phone: +81-3-3347-6006 Email: tm-otani@kddi.com Richard Rabbat Google, Inc. 1600 Amphitheatre Pkwy Mountain View, CA 94043 Email: rabbat@alum.mit.edu Sidney Shiba Email: sidney.shiba@yahoo.com Hongxiang Guo Email: hongxiang.guo@gmail.com Keiji Miyazaki Fujitsu Laboratories Ltd 4-1-1 Kotanaka Nakahara-ku, Kawasaki Kanagawa, 211-8588, Japan Phone: +81-44-754-2765 Email: miyazaki.keiji@jp.fujitsu.com Diego Caviglia Ericsson 16153 Genova Cornigliano, ITALY Phone: +390106003736 Email: diego.caviglia@ericsson.com T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 13]
Internet Drafts March 2009 Full Copyright Statement Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. All IETF Documents and the information contained therein 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 THEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF Trust 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 any IETF 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. Copies of Intellectual Property disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement any standard or specification contained in an IETF Document. Please address the information to the IETF at ietf-ipr@ietf.org. The definitive version of an IETF Document is that published by, or under the auspices of, the IETF. Versions of IETF Documents that are published by third parties, including those that are translated into other languages, should not be considered to be definitive versions of IETF Documents. The definitive version of these Legal Provisions is that published by, or under the auspices of, the IETF. Versions of these Legal Provisions that are published by third parties, including T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 14]
Internet Drafts March 2009 those that are translated into other languages, should not be considered to be definitive versions of these Legal Provisions. For the avoidance of doubt, each Contributor to the IETF Standards Process licenses each Contribution that he or she makes as part of the IETF Standards Process to the IETF Trust pursuant to the provisions of RFC 5378. No language to the contrary, or terms, conditions or rights that differ from or are inconsistent with the rights and licenses granted under RFC 5378, shall have any effect and shall be null and void, whether published or posted by such Contributor, or included with or in such Contribution. T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 15]
