Network Working Group Y. Lee Internet Draft Huawei Intended status: Standard Track Expires: August 2008 G. Bernstein Grotto Networking February 18, 2008 PCEP Requirements and Extensions for WSON Routing and Wavelength Assignment draft-lee-pce-wson-routing-wavelength-01.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 18, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This memo provides application-specific requirements and protocol enhancements for the Path Computation Element communication Protocol (PCEP) for the support of Wavelength Switched Optical Networks (WSON). Lee & Bernstein Expires August 18, 2008 [Page 1] Internet-Draft PCEP Extension for WSON February 2008 Lightpath provisioning in WSONs requires a routing and wavelength assignment (RWA) process. From a path computation perspective, wavelength assignment is the process of determining which wavelength can be used on each hop of a path and forms an additional routing constraint to optical light path computation. Different computational architectures for the RWA process are given and the PCEP extensions needed to support these architectures are defined. 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 0. Table of Contents 1. Introduction................................................3 2. Background: RWA Computation Architectures....................4 3. PCECP Requirements..........................................5 3.1. RWA Computation Options.................................5 3.2. Optimization Degree.....................................6 3.3. Wavelength Assignment and Wavelength Set Information.....7 3.4. Lightpath Route Parameters..............................7 3.5. Timeliness Characteristics of Lightpath.................7 3.6. Duration of Lightpath...................................8 3.7. Wavelength Selection Preference.........................8 4. Protocol Extensions for Support of WSON RWA..................9 4.1. RWA Computation Options.................................9 4.2. Lightpath Route Parameter TLV..........................10 4.3. Wavelength Selection Preferences.......................11 4.4. Wavelength Suggestion/Restriction TLV..................12 4.5. Error Indicator........................................13 4.6. NO-PATH Indicator......................................13 5. Manageability Considerations................................13 5.1. Control of Function and Policy.........................14 5.2. Information and Data Models, e.g. MIB module...........14 5.3. Liveness Detection and Monitoring......................14 5.4. Verifying Correct Operation............................14 5.5. Requirements on Other Protocols and Functional Components15 5.6. Impact on Network Operation............................15 6. Security Considerations.....................................15 7. IANA Considerations........................................15 Lee & Bernstein Expires August 18, 2008 [Page 2] Internet-Draft PCEP Extension for WSON February 2008 8. Acknowledgments............................................15 9. References.................................................16 9.1. Normative References...................................16 9.2. Informative References.................................16 Authors' Addresses............................................17 Intellectual Property Statement................................17 Disclaimer of Validity........................................18 1. Introduction [RFC4655] defines the PCE based Architecture and explains how a Path Computation Element (PCE) may compute Label Switched Paths (LSP) in Multiprotocol Label Switching Traffic Engineering (MPLS-TE) and Generalized MPLS (GMPLS) networks at the request of Path Computation Clients (PCCs). A PCC is shown to be any network component that makes such a request and may be for instance an Optical Switching Element with a Wavelength Division Multiplexing (WDM) network. The PCE, itself, can be located anywhere within the network, and may be within an optical switching element, a Network Management System (NMS) or Operational Support System (OSS), or may be an independent network server. The PCE communications Protocol (PCEP) is the communication protocol used between PCC and PCE, and may also be used between cooperating PCEs. [RFC4657] sets out the common protocol requirements for PCEP. Additional application-specific requirements for PCEP are deferred to separate documents. This document provides a set of application-specific PCEP requirements and protocol enhancements for support of path computation in Wavelength Switched Optical Networks (WSON). WSON refers to WDM based optical networks in which switching is performed selectively based on the wavelength of an optical signal. The path in WSON is referred to as a lightpath. A lightpath may span multiple fiber links and the path should be assigned a wavelength for each link. A transparent optical network is made up of optical devices that can switch but not convert wavelengths. In a transparent optical network, a lightpath operates on the same wavelength across all fiber links that it traverses. In such case, the lightpath is said to satisfy the wavelength-continuity constraint. Two lightpaths that share a common fiber link should not be assigned the same wavelength otherwise blocking will occur during lightpath provisioning. Therefore, assigning the proper wavelength on a Lee & Bernstein Expires August 18, 2008 [Page 3] Internet-Draft PCEP Extension for WSON February 2008 lightpath is an essential requirement in the optical path computation process. On the other hand, when a switching node has the ability to perform wavelength conversion the wavelength-continuity constraint can be relaxed, and a lightpath may use different wavelengths on different links along its route from origin to destination. It is, however, to be noted that wavelength converters may be limited due to their high cost, while the number of WDM channels that can be supported in a fiber is also limited. As a WSON can be composed of network nodes that cannot perform wavelength conversion, nodes with limited wavelength conversion, and nodes with full wavelength conversion abilities, wavelength assignment is an additional routing constraint to be considered in all lightpath computation. The remainder of this document uses terminology from [RFC4655]. 2. Background: RWA Computation Architectures The WSON framework [WSON-FRAME] document defines the following RWA computation architectures. o Combined RWA --- Both routing and wavelength assignment are performed at a single computational entity. This choice assumes that computational entity has sufficient WSON network link/nodal and topology information to be able to compute RWA. o Separate Routing and WA --- Separate entities perform routing and wavelength assignment. The path(s) obtained from the routing computational entity must be furnished to the entity performing wavelength assignment. o Routing with Distributed WA --- Routing is performed at a computational entity while wavelength assignment is performed in a distributed fashion across the nodes along the path. For the Combined RWA architecture, there are two possible computing entities: (i) the NE is the computational entity -- in this case, there is no separate PCE as the NE assumes PCE function; (ii) a separate PCE is the computational entity. This document is only concerned with case (ii). In this case, the PCE should perform both routing (R) and wavelength assignment (WA) upon request of the PCC. Lee & Bernstein Expires August 18, 2008 [Page 4] Internet-Draft PCEP Extension for WSON February 2008 For the Separate Routing and Wavelength architecture, there can be two variations: o A separate PCE will perform only wavelength assignment (WA) while the NE performs the route calculation based on its local knowledge. In this case, the NE should furnish the route list to the PCE so that the PCE would be able to assign wavelength to the route. o One PCE performs the routing (R) function while another PCE performs the Wavelength Assignment (WA) function in a tandem fashion. The fact that two PCEs are involved (one for Routing and one for Wavelength Assignment (WA)) could be invisible to the original PCC. For the Routing with Distributed WA architecture, the PCE is only responsible for routing (i.e., path computation), not for exact wavelength assignment. The exact assignment of wavelengths would be performed at the NEs along the path in a distributed fashion. However, the PCE may choose to limit the wavelengths that can be used (i.e., by specifying a wavelength set to the NEs). 3. PCECP Requirements This section provides the PCECP requirements to support WSON routing and wavelength assignment (RWA) applications. The requirements specified in this section are detailed requirements based on high- level specification in [WSON-FRAME]. 3.1. RWA Computation Options The following RWA computation options should be conveyed in the PC Request: o The request is for both Routing and Wavelength Assignment (R+WA). This case may arise when the NE is not capable of either route calculation or wavelength assignment at the node level, or when a more optimal RWA is desired. o The request is for Routing (R) only. This case may arise when the NE is not capable of route calculation at the node level while wavelength assignment is done at the node level in a distributed fashion. Lee & Bernstein Expires August 18, 2008 [Page 5] Internet-Draft PCEP Extension for WSON February 2008 o The request is for Wavelength Assignment (WA) only. This case may arise when the NE is capable of route calculation at the node level (e.g., via an IGP-TE) but with no wavelength information is available at the node level, or when two PCEs work in tandem with one performing the routing (R) function and another wavelength assignment (WA). In either case, the calculated route list at one computing entity should be supplied in the request message to the other computing entity where WA is applied. o The request is for Routing (R) with the suggested/restricted wavelength set. This is a variation from the Routing only option. With this option, the PCE computes the route and the candidate wavelengths associated with the route. In this case, the exact wavelength assignment is to be performed at the NE level. The corresponding PC Reply message should include the following information: o An indicator that conveys the original request was for (i) WA only; (ii) R+WA; (iii) R only; (iv) R with the suggested/restricted wavelength set o The route list and the recommended wavelengths to be used for the route. o In the case of failure to find a proper route or wavelengths assigned to the route, proper reasons for the failure should be conveyed: (i) route not found; (ii) wavelength not found (i.e., wavelength blocking); (iii) both route and wavelength not found. 3.2. Optimization Degree The PC Request Message should indicate the degree of optimization associated with lightpath computation. o Concurrent Optimization: multiple lightpaths requested at once. o Lightpath and backup lightpath requested at once. o Sequential Optimization: single lightpath requested. The PC Reply Message should include the original optimization degree associated with the request when replying the path computation results. Lee & Bernstein Expires August 18, 2008 [Page 6] Internet-Draft PCEP Extension for WSON February 2008 3.3. Wavelength Assignment and Wavelength Set Information The PCE MUST specify the wavelength assignment and/or wavelength set information in response to the wavelength assignment/wavelength set Request made by the PCC in the PCReq message. If the original request is either for both Routing and Wavelength Assignment or for Wavelength Assignment only, the exact wavelength assignment result can be conveyed to the PCC using the ERO object and ERO Label subobject within the ERO. Note that this is not a new requirement. [PCEP] allows this mechanism, which is defined as the Label Set mechanism in [RFC3471]. If the original request is for Routing with wavelength suggested/restricted wavelength set, then the Wavelength Set information must be provided to the PCC. 3.4. Lightpath Route Parameters The request MAY indicate the specific lightpath route parameters in the PCReq message: o Bidirectional Assignment of wavelengths for a bidirectional LSP request. This means that the same wavelength should be assigned in both directions on each hop. o Simultaneous assignment of the same wavelength to primary and backup paths. The PCRep message should include the original lightpath route parameters associated with the request when replying with the path computation results. 3.5. Timeliness Characteristics of Lightpath The request MAY indicate the specific timeliness of the computation request for a lightpath. This will likely be related to the use to which the lightpath will be put: o Time Critical: this type of request is useful for those lightpath establishment requests used for restoration of service or other high priority real time services. Lee & Bernstein Expires August 18, 2008 [Page 7] Internet-Draft PCEP Extension for WSON February 2008 o Soft Time Bounds: this type of request is a more typical new connection request. While expected to be responsive, there should be more time to take into account network optimization. o Scheduled: this type of request is useful when the requested lightpath connections are not time critical (i.e., the request is significantly ahead of their intended "in-service" time. It is to be noted that we will not explicitly deal with scheduled case in this document but the optimization can be handled via [PCE-GCO]. The reply should indicate the original timeliness characteristics of the lightpath request with path computation results. 3.6. Duration of Lightpath The request MAY indicate specific lightpath duration information associated with the request. This may be useful to the PCE since it is not worthwhile to optimize lightpaths with relatively short duration as compared to pseudo-static paths. 3.7. Wavelength Selection Preference The PC Request MAY indicate computation objective functions that specify the Wavelength Selection Preference to which a path computation request is applied. The Wavelength Selection Preference to be supported at the minimum is: o Random o First Fit o Most Used o Least Loaded o Don't care: default Note that the objective functions to be supported for a single LSP request are listed in [PCEP] and [PCE-OF] and that the objective functions to be supported for a concurrent LSP request are listed in [PCE-GCO] and [PCE-OF]. Lee & Bernstein Expires August 18, 2008 [Page 8] Internet-Draft PCEP Extension for WSON February 2008 The PCRep should indicate which wavelength selection preference has actually been applied. 4. Protocol Extensions for Support of WSON RWA This section describes PCEP extension necessary to meet the requirements set out in the previous section. 4.1. RWA Computation Options The PCC has to include the RWA computation option in the PCReq message in order to convey a particular computation option. To support such indication a new flag, the RC flag, is defined in the RP (Request Parameter) Object. The RC flag is defined in the Flags field of the RP (Request Parameter) object as follows. Bit number assignment to be confirmed by IANA (see Section 8). Bit Name Description Reference 10-11 RC-bits Routing Wavelength Computation This document RC bits (Routing wavelength Computation bits - 2 bits): o 11: Request is for both R (Routing) and Wavelength Assignment (WA). o 01: Request is for Wavelength Assignment (WA) only. o 10: Request is for Routing (R) with suggested/restricted Wavelength Set o 00: Request is for Routing (R) only. When the RC bits are set to 11 in a PCReq message, the requesting PCC requires the PCE to provide in the PCRep message the assigned wavelength associated with the computed path. This request is for both Routing (R) and Wavelength Assignment (WA). When the RC bits are set to 01 in a PCReq message, the requesting PCC requires the PCE only to provide wavelength assignment (WA). In such case, the PCC must provide the already computed route (as indicated Lee & Bernstein Expires August 18, 2008 [Page 9] Internet-Draft PCEP Extension for WSON February 2008 by the ERO and the Bandwidth Object following the RP object) to which the PCE would assign the wavelengths. Note that this option is to fulfill one of the RWA computational architectures, namely, the Separate Routing and WA option. When the RC bits are set to 10, then the PCE is expected to provide some suggestive or restrictive wavelength information associated with the route. When the RC bits are set to 11, 01, or 10, then additional parameters associated with the requested lightpath SHOULD be provided in optional Lightpath Route Parameter TLV (as specified in Section 3.4) within the RP object. See Section 4.2 for the encoding of Lightpath Route Parameter TLV. The RP object in the PCRep message SHOULD properly indicate the original request for the RWA Computation (RC) bit and I bit that have actually been applied by the PCE. The actual route list and wavelength assignment is to be found in the ERO within ERO Label subobjects. ERO Label subobjects can be used to indicate the wavelength to be used on particular links. Note that GMPLS signaling [RFC3473] supports an explicit route object (ERO) and with ERO Label subobjects. 4.2. Lightpath Route Parameter TLV When the RC bit is set to 11, 01, or 10 in the RP object in a PCReq message, then the following Lightpath Route Parameter TLV SHOULD be included as part of the RP object within the PCReq message. The format of the Lightpath Route Parameter TLV is as follows: Lee & Bernstein Expires August 18, 2008 [Page 10] Internet-Draft PCEP Extension for WSON 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |I|S| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type To be defined by IANA (suggested value = x) Length 2 bits Value I bit: 0 or 1 S bit: 0 or 1 Figure 1 The Lightpath Route Parameter TLV in the RP object in the PCReq Message I bit (Bidirectional Assignment of wavelengths - 1 bit): o 0: Request is for bidirectional assignment of wavelengths o 1: Request is for unidirectional assignment of wavelengths S bit (Same Wavelength to primary and backup paths - 1 bit): o 0: Request is for assignment of the same wavelength to primary and backup paths. o 1: Request is for assignment of the different wavelength to primary and backup paths. 4.3. Wavelength Selection Preferences When the RC (RWA Computation) flags in the RP object of a PCReq indicate computing wavelength assignment, then the following Wavelength Selection Preference TLV MAY be included in the RP object as an optional TLV. The format of the Wavelength Selection Preference TLV is as follows: Lee & Bernstein Expires August 18, 2008 [Page 11] Internet-Draft PCEP Extension for WSON 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Wavelength Selection Preference | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type To be defined by IANA (suggested value = x) Length 32 bits Value Wavelength Selection Preference Figure 2 The Wavelength Selection/Assignment Preferences TLV in the RP object in the PCReq Message Five wavelength selection preferences are defined in this document and their identifier should be assigned by IANA (suggested value) Function Code Description -------- ------------ 1 Random 2 First Fit 3 Most Used 4 Least Loaded 5 Don't Care The Wavelength Selection Preference TLV should also be included in the RP object in the PCRep message to indicate which wavelength selection preference has actually been applied by the PCE in its wavelength assignment procedure. 4.4. Wavelength Suggestion/Restriction TLV With the Routing with Distributed Wavelength Assignment option, the PCRep should specify the wavelength set information in response to the wavelength assignment/wavelength set Request made by the PCC in the PCReq message if so requested by the setting of the RC bits in the RP object in the PCReq message. Lee & Bernstein Expires August 18, 2008 [Page 12] Internet-Draft PCEP Extension for WSON February 2008 We refer to this information as wavelength restriction TLV. The encoding of wavelength Suggestion/Restriction TLV is to be provided in the next version. 4.5. Error Indicator To indicate errors associated with the RWA request, a new Error-Type (15) and subsequent error-values are defined as follows for inclusion in the PCEP-ERROR object. If a PCE receives a RWA computation request and the PCE is not capable of RWA, the PCE MUST send a PCErr message with a PCEP ERROR object (Error-Type=15) and an Error-Value (Error-Value=1). The corresponding RWA computation request MUST be cancelled. To indicate an error associated with policy violation, a new error value "RWA not allowed" is added to the existing error code for policy violation (Error-Type=6) as defined in [PCEP]. If a PCE receives a RWA computation request which is not compliant with administrative privileges (i.e., the PCE policy does not support RWA), the PCE MUST send a PCErr message with a PCEP-ERROR Object (Error-Type=6) and an Error-Value (Error-Value=3). The corresponding RWA computation MUST be cancelled. 4.6. NO-PATH Indicator To communicate the reason(s) for not being able to find RWA computation, the NO-PATH object MAY be used in the PCRep message. The NO-PATH object is defined in [PCEP]. As defined in [PCEP], the NO-PATH object carries the NO-PATH_VECTOR TLV which has a flags field. One new bit flag is defined in this document to indicate RWA-specific computation failures as follows: 0x10: when set, the PCE indicates that no wavelength was found associated with RWA computation in the PCRep message. 5. Manageability Considerations Manageability of WSON Routing and Wavelength Assignment (RWA) with PCE must address the following considerations: Lee & Bernstein Expires August 18, 2008 [Page 13] Internet-Draft PCEP Extension for WSON February 2008 5.1. Control of Function and Policy In addition to the parameters already listed in Section 8.1 of [PCEP], a PCEP implementation SHOULD allow configuring the following PCEP session parameters on a PCC: o The ability to send a WSON RWA request. In addition to the parameters already listed in Section 8.1 of [PCEP], a PCEP implementation SHOULD allow configuring the following PCEP session parameters on a PCE: o The support for WSON RWA. o The maximum number of synchronized path requests associated with WSON RWA per request message. o A set of WSON RWA specific policies (authorized sender, request rate limiter, etc). These parameters may be configured as default parameters for any PCEP session the PCEP speaker participates in, or may apply to a specific session with a given PCEP peer or a specific group of sessions with a specific group of PCEP peers. 5.2. Information and Data Models, e.g. MIB module Extensions to the PCEP MIB module defined in [PCEP-MIB] should be defined, so as to cover the WSON RWA information introduced in this document. A future revision of this document will list the information that should be added to the MIB module. 5.3. Liveness Detection and Monitoring Mechanisms defined in this document do not imply any new liveness detection and monitoring requirements in addition to those already listed in section 8.3 of [PCEP]. 5.4. Verifying Correct Operation Mechanisms defined in this document do not imply any new verification requirements in addition to those already listed in section 8.4 of [PCEP] Lee & Bernstein Expires August 18, 2008 [Page 14] Internet-Draft PCEP Extension for WSON February 2008 5.5. Requirements on Other Protocols and Functional Components The PCE Discovery mechanisms ([ISIS PCED] and [OSPF PCED]) may be used to advertise WSON RWA path computation capabilities to PCCs. 5.6. Impact on Network Operation Mechanisms defined in this document do not imply any new network operation requirements in addition to those already listed in section 8.6 of [PCEP]. 6. Security Considerations This document has no requirement for a change to the security models within PCEP [PCEP]. However the additional information distributed in order to address the RWA problem represents a disclosure of network capabilities that an operator may wish to keep private. Consideration should be given to securing this information. 7. IANA Considerations A future revision of this document will present requests to IANA for codepoint allocation. 8. Acknowledgments The authors would like to thank Adrian Farrel for many helpful comments that greatly improved the contents of this draft. This document was prepared using 2-Word-v2.0.template.dot. Lee & Bernstein Expires August 18, 2008 [Page 15] Internet-Draft PCEP Extension for WSON 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. [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, August 2006. [RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE) Communication Protocol Generic Requirements", RFC 4657, September 2006. [PCEP] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) communication Protocol (PCEP) - Version 1", draft-ietf-pce-pcep, work in progress. 9.2. Informative References [PCE-OF] Le Roux, JL., Vasseur, JP., and Y. Lee, "Objective Function encoding in Path Computation Element communication and discovery protocols", draft-ietf-pce-pce-of, work in progress. [PCE-GCO] Y. Lee, J.L. Le Roux, D. King, and E. Oki, "Path Computation Element Communication Protocol (PCECP) Requirements and Protocol Extensions In Support of Global Concurrent Optimization", draft-ietf-pce-global-concurrent- optimization, work in progress. [WSON-FRAME] Bernstein, G. and Lee, Y. (Editors), and W. Imajuku, "Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks", draft-bernstein-ccamp-wavelength- switched, work in progress. Lee & Bernstein Expires August 18, 2008 [Page 16] Internet-Draft PCEP Extension for WSON February 2008 [ISIS-PCED] Le Roux, J. and JP. Vasseur, "IS-IS protocol extensions for Path Computation Element (PCE) Discovery", draft-ietf- pce-disco-proto-isis, work in progress. [OSPF-PCED] Le Roux, J. and JP. Vasseur, "OSPF protocol extensions for Path Computation Element (PCE) Discovery", draft-ietf- pce-disco-proto-ospf, work in progress. Authors' Addresses Young Lee (Ed.) Huawei Technologies 1700 Alma Drive, Suite 100 Plano, TX 75075, USA Phone: (972) 509-5599 (x2240) Email: ylee@huawei.com Greg Bernstein (Ed.) Grotto Networking Fremont, CA, USA Phone: (510) 573-2237 Email: gregb@grotto-networking.com 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. Lee & Bernstein Expires August 18, 2008 [Page 17] Internet-Draft PCEP Extension for WSON 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. Lee & Bernstein Expires August 18, 2008 [Page 18]