INTERNET-DRAFT Tomohiro Otani Intended status: Informational Kenichi Ogaki Expires:March 2009 KDDI R&D Labs Diego Caviglia Ericsson Sept 17, 2008 Requirements for GMPLS applications of PCE Document: draft-ietf-pce-gmpls-aps-req-00.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. Abstract The initial effort of PCE WG is specifically focused on MPLS (Multi- protocol label switching). As a next step, this draft describes functional requirements for GMPLS (Generalized MPLS) application of PCE (Path computation element). Table of Contents Status of this Memo................................................ 1 Abstract........................................................... 1 1. Introduction.................................................... 3 2. Conventions used in this document............................... 3 3. GMPLS applications of PCE....................................... 3 4. Requirement for GMPLS application of PCE........................ 4 5. Security consideration.......................................... 5 T. Otani et al. Informational - Expires March 2009 [Page 1] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 6. IANA Considerations............................................. 5 7. Acknowledgement................................................. 5 8. Intellectual property considerations............................ 5 9. Informative references.......................................... 6 Author's Addresses................................................. 7 Document expiration................................................ 7 Copyright statement................................................ 7 T. Otani et al. Informational - Expires March 2009 [Page 2] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 1. Introduction The initial effort of PCE WG is focused on solving the path computation problem over domains in MPLS networks. As the same case with MPLS, service providers (SPs) have also come up with requirements for path computation in GMPLS networks such as photonics, TDM-based or Ethernet-based networks as well. [PCE-ARCH] and [PCECP-REQ] discuss the framework and requirements for PCE on both packet MPLS networks and (non-packet switch capable) GMPLS networks. This document complements these documents by providing some consideration of GMPLS applications in the inter- domain networking environment and indicating a set of requirements for the extended definition of series of PCE related protocols. Constraint based shortest path first (CSPF) computation within a domain or over domains for signaling GMPLS Label Switched Paths (LSPs) is more stringent than that of MPLS LSPs [MPLS-AS], because the additional constraints, e.g., interface switching capability, link encoding, link protection capability and so forth need to be considered to establish GMPLS LSPs [CSPF]. GMPLS signaling protocol [RFC3471, RFC3473] is designed taking into account bi-directionality, switching type, encoding type, SRLG, and protection attributes of the TE links spanned by the path, as well as LSP encoding type and switching type for the end points, appropriately. This document provides the investigated results of GMPLS applications of PCE especially for the support of GMPLS inter-domain path computation. This document also outlines GMPLS inter-domain architecture, and provides requirements for GMPLS applications of PCE in the GMPLS inter-domain environment. 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. GMPLS applications of PCE 3.1 GMPLS network model Figure 1 depicts a typical network, consisting of several GMPLS domains, assumed in this document. D1, D2, D3 and D4 have multiple GMPLS inter-domain connections, and D5 has only one GMPLS inter- domain connection. These domains follow the definition in [RFC4726]. +---------+ +---------|GMPLS D2|----------+ | +----+----+ | +----+----+ | +----+----+ +---------+ T. Otani et al. Informational - Expires March 2009 [Page 3] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 |GMPLS D1| | |GMPLS D4|---|GMPLS D5| +----+----+ | +----+----+ +---------+ | +----+----+ | +---------|GMPLS D3|----------+ +---------+ Figure 1: GMPLS Inter-domain network model. Each domain is configured using various switching and link technologies defined in [Arch] and an end-to-end route needs to respect TE link attributes like multiplexing type, encoding type, etc., making the problem a bit different from the case of classical (packet) MPLS. In order to route from one GMPLS domain to another GMPLS domain appropriately, each domain manages traffic engineering database (TED) by PCE, and exchanges or provides route information of paths, while concealing its internal topology information. 3.2 Path computation in GMPLS network [CSPF] describes consideration of GMPLS TE attributes during path computation. Ingress Transit Egress +-----+ link1-2 +-----+ link2-3 +-----+ link3-4 +-----+ |Node1|------------>|Node2|------------>|Node3|------------>|Node4| | |<------------| |<------------| |<------------| | +-----+ link2-1 +-----+ link3-2 +-----+ link4-3 +-----+ Figure 2: Path computation in GMPLS networks. For the simplicity in consideration, the below basic assumptions are made when the LSP is created. (1) Switching capabilities of outgoing links from the ingress and egress nodes (link1-2 and link4-3 in Figure .) must be consistent with each other. (2) SC of all transit links including incoming links to the ingress and egress nodes (link2-1 and link3-4) should be consistent with switching type of a LSP to be created. (3) Encoding-types of all transit links should be consistent with encoding type of a LSP to be created. [CSPF] indicates the possible table of switching capability, encoding type and bandwidth at the ingress link, transiting links and the egress link which need to be satisfied with the created LSP. 4. Requirement for GMPLS application of PCE In this section, we describe requirements for GMPLS applications of PCE in order to establish GMPLS LSP over domains. 4.1 PCE requirements T. Otani et al. Informational - Expires March 2009 [Page 4] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 As for path computation in GMPLS networks as discussed in section 3, the PCE needs to consider the GMPLS TE attributes appropriately according to tables in [CSPF] once a PCC or another PCE requests a path computation. Indeed, the path calculation request message from the PCC or the PCE needs to contain the information specifying appropriate attributes. Additional attributes to those already defined in [PCECP] are as follows. (1) Switching capability: PSC1-4, L2SC, TDM, lambda, LSC, FSC (2) Encoding type: as defined in [RFC4202], [RFC4203], e.g., Ethernet, SONET/SDH, Lambda, etc. (3) e2e Path protection type: as defined in [RFC4872], e.g., 1+1 protection, 1:1 protection, (pre-planned) rerouting, etc. (4) Administrative group: as defined in [RFC3630] (5) Link Protection type: as defined in [RFC4203] 4.2 PCC requirements As described above, a PCC needs to support to initiate path computation request specifying abovementioned attributes. Afterwards, GMPLS signaling will be invoked according to the responded messages from the PCE. 4.3 GMPLS PCE Management PCE related Management Information Bases need to consider extensions to be satisfied with requirements for GMPLS applications. For extensions, [GMPLS-TEMIB] are defined to manage TE database and may be referred to accommodate GMPLS TE attributes in the PCE. 5. Security consideration PCE extensions to support GMPLS should be considered under the same security as current work. This extension will not change the underlying security issues. 6. IANA Considerations This document has no actions for IANA. 7. Acknowledgement The author would like to express the thanks to Shuichi Okamoto for his comments. 8. Intellectual property considerations The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to T. Otani et al. Informational - Expires March 2009 [Page 5] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 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. 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. 9. Informative references [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [PCE-ARCH] A. Farrel, et al, "A Path Computation Element (PCE)- Based Architecture", RFC4655, Aug., 2006. [PCECP-REQ] J. Ash, et al, "Path computation element (PCE) communication protocol generic requirements", RFC4657, Sept., 2007. [MPLS-AS] R. Zhan, et al, "MPLS Inter-Autonomous System (AS) Traffic Engineering (TE) Requirements", RFC4216, November 2005. [CSPF] T. Otani, et al, "Considering Generalized Multiprotocol Label Switching Traffic Engineering Attributes During Path Computation", draft-otani- ccamp-gmpls-cspf-constraints-07.txt, Feb., 2008. [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. [RFC4726] A. Farrel, et al, "A framework for inter-domain MPLS traffic engineering", RFC4726, November 2006. [Arch] E. Mannie, et al, "Generalized Multi-Protocol Label Switching Architecture", RFC3945, October, 2004. [PCECP] J.P. Vasseur, et al, "Path Computation Element (PCE) Communication Protocol (PCEP)", draft-ietf-pce-pcep- 15.txt, March 2008. [RFC4202] K. Kompella, and Y. Rekhter, "Routing Extensions in Support of Generalized Multi-Protocol Label Switching", RFC4202, Oct. 2005. T. Otani et al. Informational - Expires March 2009 [Page 6] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 [RFC4203] K. Kompella, and Y. Rekhter, "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching", RFC4203, Oct. 2005. [RFC4872] J.P. Lang, Ed., "RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery", RFC4872, May 2007. [GMPLS-TEMIB] T. Nadeau and A. Farrel, Ed., "Generalized Multiprotocol Label Switching (GMPLS) Traffic Engineering Management Information Base", RFC4802, Feb. 2007. [RFC3630] D. Katz et al, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC3630, September 2003. Author's Addresses Tomohiro Otani KDDI R&D Laboratories, Inc. 2-1-15 Ohara Kamifukuoka Saitama, 356-8502. Japan Phone: +81-49-278-7357 Email: otani@kddilabs.jp Kenichi Ogaki KDDI R&D Laboratories, Inc. 2-1-15 Ohara Kamifukuoka Saitama, 356-8502. Japan Phone: +81-49-278-7897 Email: ogaki@kddilabs.jp Diego Caviglia Ericsson 16153 Genova Cornigliano, ITALY Phone: +390106003736 Email: diego.caviglia@ericsson.com Document expiration This document will be expired in March 31, 2009, unless it is updated. 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. 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 T. Otani et al. Informational - Expires March 2009 [Page 7] Internet Drafts draft-ietf-pce-gmpls-aps-req-00.txt Sept. 2008 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. T. Otani et al. Informational - Expires March 2009 [Page 8]