Network Working Group G. Bernstein Internet Draft Grotto Networking Updates: 6205 Sugang Xu Intended status: Standards Track NICT Y.Lee Huawei Expires: September 2015 G. Martinelli Cisco Hiroaki Harai NICT March 9, 2015 Signaling Extensions for Wavelength Switched Optical Networks draft-ietf-ccamp-wson-signaling-10.txt Abstract This memo provides extensions to Generalized Multi-Protocol Label Switching (GMPLS) signaling for control of Wavelength Switched Optical Networks (WSON). Such extensions are applicable in WSONs under a number of conditions including: (a) when optional processing, such as regeneration, must be configured to occur at specific nodes along a path, (b) where equipment must be configured to accept an optical signal with specific attributes, or (c) where equipment must be configured to output an optical signal with specific attributes. In addition this memo provides mechanisms to support distributed wavelength assignment with choice in distributed wavelength assignment algorithms. 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 Bernstein, et al. Expires September 2015 [Page 1] Internet-Draft WSON Signaling Extensions March 2015 The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on September 9, 2015. Copyright Notice Copyright (c) 2014 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. 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 [RFC2119]. Table of Contents 1. Introduction...................................................3 2. Terminology....................................................3 3. Requirements for WSON Signaling................................4 3.1. WSON Signal Characterization..............................4 3.2. Per Node Processing Configuration.........................5 3.3. Bidirectional WSON LSPs...................................6 3.4. Distributed Wavelength Assignment Selection Method........6 3.5. Optical Impairments.......................................6 4. WSON Signal Traffic Parameters, Attributes and Processing......6 4.1. Traffic Parameters for Optical Tributary Signals..........7 4.2. WSON Processing HOP Attribute TLV.........................7 4.2.1. Resource Block Information Sub-TLV......................8 4.2.2. Wavelength Selection Sub-TLV............................9 5. Security Considerations.......................................11 6. IANA Considerations...........................................12 7. Acknowledgments...............................................13 8. References....................................................14 8.1. Normative References.....................................14 Bernstein, et al. Expires September 2015 [Page 2] Internet-Draft WSON Signaling Extensions March 2015 8.2. Informative References...................................15 Author's Addresses...............................................15 1. Introduction This memo provides extensions to Generalized Multi-Protocol Label Switching (GMPLS) signaling for control of Wavelength Switched Optical Networks (WSON). Fundamental extensions are given to permit simultaneous bidirectional wavelength assignment while more advanced extensions are given to support the networks described in [RFC6163] which feature connections requiring configuration of input, output, and general signal processing capabilities at a node along a Label Switched Path (LSP). These extensions build on previous work for the control of lambda and G.709 based networks. This document updates [RFC6205] as make it applicable to WSON-LSC capable equipment. Related references with this document are [WSON-Info] that provides a high-level information model and and [WSON-Encode] that provides common encodings that can be applicable to other protocol extensions such as routing. 2. Terminology CWDM: Coarse Wavelength Division Multiplexing. DWDM: Dense Wavelength Division Multiplexing. 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 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, et al. Expires September 2015 [Page 3] Internet-Draft WSON Signaling Extensions March 2015 AWG: Arrayed Waveguide Grating. OXC: Optical Cross-Connect. Optical Transmitter: A device that has both a laser tuned on certain wavelength and electronic components, which converts electronic signals into optical signals. Optical Responder: A device that has both optical and electronic components. It detects optical signals and converts optical signals into electronic signals. Optical Transponder: A device that has both an optical transmitter and an optical responder. Optical End Node: The end of a wavelength (optical lambdas) lightpath in the data plane. It may be equipped with some optical/electronic devices such as wavelength multiplexers/demultiplexer (e.g. AWG), optical transponder, etc., which are employed to transmit/terminate the optical signals for data transmission. 3. Requirements for WSON Signaling The following requirements for GMPLS based WSON signaling are in addition to the functionality already provided by existing GMPLS signaling mechanisms. 3.1. WSON Signal Characterization WSON signaling needs to convey sufficient information characterizing the signal to allow systems along the path to determine compatibility and perform any required local configuration. Examples of such systems include intermediate nodes (ROADMs, OXCs, Wavelength converters, Regenerators, OEO Switches, etc...), links (WDM systems) and end systems (detectors, demodulators, etc...). The details of any local configuration processes are out of the scope of this document. From [RFC6163] we have the following list of WSON signal characteristic information 1. Optical tributary signal class (modulation format). 2. FEC: whether forward error correction is used in the digital stream and what type of error correcting code is used 3. Center frequency (wavelength) Bernstein, et al. Expires September 2015 [Page 4] Internet-Draft WSON Signaling Extensions March 2015 4. Bit rate 5. G-PID: General Protocol Identifier for the information format The first three items on this list can change as a WSON signal traverses a network with regenerators, OEO switches, or wavelength converters. These parameters are summarized in the Optical Interface Class as defined in the [WSON-Info] and the assumption is that a class always includes signal compatibility information. An ability to control wavelength conversion already exists in GMPLS signaling along with the ability to share client signal type information (G-PID). In addition, bit rate is a standard GMPLS signaling traffic parameter. It is referred to as Bandwidth Encoding in [RFC3471]. 3.2. Per Node Processing Configuration In addition to configuring a node along an LSP to input or output a signal with specific attributes, we may need to signal the node to perform specific processing, such as 3R regeneration, on the signal at a particular node. [RFC6163] discussed three types of processing: (A) Regeneration (possibly different types) (B) Fault and Performance Monitoring (C) Attribute Conversion The extensions here provide for the configuration of these types of processing at nodes along an LSP. 3.3. Bidirectional WSON LSPs WSON signaling can support LSP setup consistent with the wavelength continuity constraint for bidirectional connections. The following cases need to be separately supported: (a) Where the same wavelength is used for both upstream and downstream directions (b) Where different wavelengths can be used for both upstream and downstream directions. This document will review existing GMPLS bidirectional solutions according to WSON case. 3.4. Distributed Wavelength Assignment Selection Method Bernstein, et al. Expires September 2015 [Page 5] Internet-Draft WSON Signaling Extensions March 2015 WSON signaling can support the selection of a specific distributed wavelength assignment method. This method is beneficial in cases of equipment failure, etc., where fast provisioning used in quick recovery is critical to protect carriers/users against system loss. This requires efficient signaling which supports distributed wavelength assignment, in particular when the centralized wavelength assignment capability is not available. As discussed in the [RFC6163] different computational approaches for wavelength assignment are available. One method is the use of distributed wavelength assignment. This feature would allow the specification of a particular approach when more than one is implemented in the systems along the path. 3.5. Optical Impairments This draft does not address signaling information related to optical impairments. 4. WSON Signal Traffic Parameters, Attributes and Processing As discussed in [RFC6163] single channel optical signals used in WSONs are called "optical tributary signals" and come in a number of classes characterized by modulation format and bit rate. Although WSONs are fairly transparent to the signals they carry, to ensure compatibility amongst various networks devices and end systems, it can be important to include key lightpath characteristics as traffic parameters in signaling [RFC6163]. LSPs signaled through extensions provided in this document MUST apply the following signaling parameters: . Switching Capability = WSON-LSC ([WSON-OSPF]). . Encoding Type = Lambda ([RFC3471]) . Label Format = as defined in [RFC6205] [RFC6205] defines the label format as applicable to LSC capable device. 4.1. Traffic Parameters for Optical Tributary Signals In [RFC3471] we see that the G-PID (client signal type) and bit rate (byte rate) of the signals are defined as parameters and in [RFC3473] they are conveyed Generalized Label Request object and the Bernstein, et al. Expires September 2015 [Page 6] Internet-Draft WSON Signaling Extensions March 2015 RSVP SENDER_TSPEC/FLOWSPEC objects respectively. 4.2. WSON Processing HOP Attribute TLV Section 3.2. provided the requirements for signaling to indicate to a particular node along an LSP what type of processing to perform on an optical signal or how to configure that node to accept or transmit an optical signal with particular attributes. To target a specific node, this section defines a WSON Processing HOP Attribute TLV. This TLV is encoded as an attributes TLV, see [RFC5420]. The TLV is carried in the ERO and RRO LSP Attribute Subobjects, and processed according to the procedures, defined in [RSVP-RO]. The type value of the WSON Processing HOP Attribute TLV is TBD by IANA. The WSON Processing HOP Attribute TLV carries one or more sub-TLVs with the following format: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | // Value // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type The identifier of the sub-TLV. Length Indicates the total length of the sub-TLV in octets. That is, the combined length of the Type, Length, and Value fields, i.e., four plus the length of the Value field in octets. The entire sub-TLV MUST be padded with zeros to ensure four-octet alignment of the sub-TLV. The Length field does not include any padding. Value Zero or more octets of data carried in the sub-TLV. Sub-TLV ordering is significant and MUST be preserved. Error Bernstein, et al. Expires September 2015 [Page 7] Internet-Draft WSON Signaling Extensions March 2015 processing follows [RSVP-RO]. The following sub-TLV types are defined in this document: Sub-TLV Name Type Length -------------------------------------------------------------- ResourceBlockInfo 1 variable WavelengthSelection 2 1 (3 octets padding) The TLV can be represented in Reduced Backus-Naur Form (RBNF) [RFC5511] syntax as: ::= [] [] 4.2.1. ResourceBlockInfo Sub-TLV The format of the ResourceBlockInfo sub-TLV value field is defined in Section 4 of [WSON-Encode]. It is a list of available Optical Interface Classes and processing capabilities. At least one ResourceBlockInfo sub-TLV MUST be present in the WSON_ Processing HOP Attribute TLV. No more than two ResourceBlockInfo sub-TLVs SHOULD be present. Any present ResourceBlockInfo sub-TLVs MUST be processed in the order received, and extra (unprocessed) SHOULD be ignored. The ResourceBlockInfo field contains several information elements as defined by [WSON-Encode]. The following rules apply to the sub-TLV: o RB Set Field can carry one or more RB Identifier. Only the first of RB Identifier listed in the RB Set Field SHALL be processed, any others SHOULD be ignored. o In the case of unidirectional LSPs, only one ResourceBlockInfo sub-TLV SHALL be processed and the I and O bits can be safely ignored. o In the case of a bidirectional LSP, there MUST be either: (a) only one ResourceBlockInfo sub-TLV present in a WSON_Processing HOP Attribute TLV, and the bits I and O both set to 1, or (b) two ResourceBlockInfo sub-TLVs present, one of which has only the I bit set and the other of which has only the O bit set. Bernstein, et al. Expires September 2015 [Page 8] Internet-Draft WSON Signaling Extensions March 2015 o The rest of information carried within the ResourceBlockInfo sub-TLV includes Optical Interface Class List, Input Bit Rate List and Processing Capability List. These lists MAY contain one or more elements. These elements apply equally to both bidirectional and unidirectional LSPs. Any violation of these rules detected by a transit or egress node SHALL be treated as an error and be processed per [RSVP-RO]. A ResourceBlockInfo sub-TLV can be constructed by a node and added to a ERO_HOP_ATTRIBUTE subobject in order to be processed by downstream nodes (transit and egress). As defined in [RSVP-RO], the R bit reflects the LSP_REQUIRED_ATTRIBUTE and LSP_ATTRIBUTE semantic defined in [RFC5420] and SHOULD be set accordingly. Once a node properly parses a ResourceBlockInfo Sub-TLV received in an ERO_HOP_ATTRIBUTE subobject (according to the rules stated above and in [RSVP-RO]), the node allocates the indicated resources, e.g., the selected regeneration pool, for the LSP. In addition, the node SHOULD report compliance by adding a RRO_HOP_ATTRIBUTE subobject with the WSON Processing HOP Attribute TLV (and its sub- TLVs) indicating the utilized resources. ResourceBlockInfo Sub-TLVs carried in a RRO_HOP_ATTRIBUTE subobject are subject to [RSVP-RO] and standard RRO processing, see [RFC3209]. 4.2.2. WavelengthSelection Sub-TLV Routing + Distributed Wavelength Assignment (R+DWA) is one of the options defined by the [RFC6163]. The output from the routing function will be a path but the wavelength will be selected on a hop-by-hop basis. As discussed in [HZang00], a number of different wavelength assignment algorithms may be employed. In addition as discussed in [RFC6163] the wavelength assignment can be either for a unidirectional lightpath or for a bidirectional lightpath constrained to use the same lambda in both directions. In order to indicate wavelength assignment directionality and wavelength assignment method, the Wavelength Selection, or WavelengthSelection, sub-TLV is defined to be carried in the WSON Processing HOP Attribute TLV defined above. The WavlengthSelection sub-TLV value field is defined as: 0 1 2 3 Bernstein, et al. Expires September 2015 [Page 9] Internet-Draft WSON Signaling Extensions March 2015 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |W| WA Method | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: W (1 bit): 0 denotes requiring the same wavelength in both directions, 1 denotes that different wavelengths on both directions are allowed. Wavelength Assignment (WA) Method (7 bits): 0 - unspecified (any); This does not constrain the WA method used by a specific node. This value is implied when the WavelengthSelection Sub-TLV is absent. 1 - First-Fit. All the wavelengths are numbered and this WA method chooses the available wavelength with the lowest index. 2 - Random. This WA method chooses an available wavelength randomly. 3 - Least-Loaded (multi-fiber). This WA method selects the wavelength that has the largest residual capacity on the most loaded link along the route. This method is used in multi-fiber networks. If used in single-fiber networks, it is equivalent to the FF WA method. 4- 127: Unassigned. The processing rules of this TLV are as follows: If a receiving node does not support the attribute(s), its behaviors are specified below: - W bit not supported: a PathErr MUST be generated with the Error Code "Routing Problem" (24) with error sub-code "Unsupported WavelengthSelection Symmetry value" (value to be assigned by IANA, suggested value: 107). - WA method not supported: a PathErr MUST be generated with the Error Code "Routing Problem" (24) with error sub-code "Unsupported Wavelength Assignment value" (value to be assigned by IANA, suggested value: 108). Bernstein, et al. Expires September 2015 [Page 10] Internet-Draft WSON Signaling Extensions March 2015 A WavelengthSelection sub-TLV can be constructed by a node and added to a ERO_HOP_ATTRIBUTE subobject in order to be processed by downstream nodes (transit and egress). As defined in [RSVP-RO], the R bit reflects the LSP_REQUIRED_ATTRIBUTE and LSP_ATTRIBUTE semantic defined in [RFC5420] and SHOULD be set accordingly. Once a node properly parses the WavelengthSelection Sub-TLV received in an ERO_HOP_ATTRIBUTE subobject, the node use the indicated wavelength assignment method (at that hop) for the LSP. In addition, the node SHOULD report compliance by adding a RRO_HOP_ATTRIBUTE subobject with the WSON Processing HOP Attribute TLV (and its sub-TLVs) indicated the utilized method. WavelengthSelection Sub-TLVs carried in a RRO_HOP_ATTRIBUTE subobject are subject to [RSVP-RO] and standard RRO processing, see [RFC3209]. 5. Security Considerations This document is built on the mechanisms defined in [RFC3473], and only differs in specific information communicated. As such, this document introduces no new security considerations to the existing GMPLS signaling protocols. See [RFC3473], for details of the supported security measures. Additionally, [RFC5920] provides an overview of security vulnerabilities and protection mechanisms for the GMPLS control plane. 6. IANA Considerations Upon approval of this document, IANA is requested to make the assignment of a new value for the existing "Attributes TLV Space" registry located at http://www.iana.org/assignments/rsvp-te- parameters/rsvp-te-parameters.xhtml, as updated by [RSVP-RO]: Type Name Allowed on Allowed on Allowed on Reference LSP LSP REQUIRED RO LSP ATTRIBUTES ATTRIBUTES Attribute Subobject TBA WSON No No Yes [This.I-D] Processing HOP Attribute Bernstein, et al. Expires September 2015 [Page 11] Internet-Draft WSON Signaling Extensions March 2015 TLV Upon approval of this document, IANA is requested to create a new registry named "Sub-TLV Types for WSON Processing HOP Attribute TLV" located at http://www.iana.org/assignments/rsvp-te-parameters/rsvp- te-parameters.xhtml. The following entries are to be added: Value Sub-TLV Type Reference 1 ResourceBlockInfo [This.I-D] 2 WavelengthSelection [This.I-D] All assignments are to be performed via Standards Action and Specification Required policies as defined in [RFC5226 ]. Upon approval of this document, IANA is requested to create a new registry named "Values for Wavelength Assignment Method field in WavelengthSelection Sub-TLV" located at http://www.iana.org/assignments/rsvp-te-parameters/rsvp-te- parameters.xhtml. The following entries are to be added: Value Meaning Reference 0 unspecified [This.I-D] 1 First-Fit [This.I-D] 2 Random [This.I-D] 3 Least-Loaded (multi-fiber) [This.I-D] 4-127 unassigned All assignments are to be performed via Standards Action and Specification Required policies as defined in [RFC5226 ]. Upon approval of this document, IANA is requested to make the assignment of a new value for the existing "Sub-Codes . 24 Routing Bernstein, et al. Expires September 2015 [Page 12] Internet-Draft WSON Signaling Extensions March 2015 Problem" registry located at http://www.iana.org/assignments/rsvp- parameters/rsvp-parameters.xml: Value Description Reference 107 Unsupported WavelengthSelection symmetry value [This.I-D] 108 Unsupported Wavelength Assignment value [This.I-D] 7. Acknowledgments Authors would like to thanks Lou Berger, Cyril Margaria and Xian Zhang for comments and suggestions. 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. [RFC6205] T. Otani, H. Guo, K. Miyazaki, D. Caviglia, "Generalized Labels for Lambda-Switch-Capable Label Switching Routers", RFC 6205, March 2011. [WSON-Encode] Bernstein G., Lee Y., Li D., and W. Imajuku, "Routing and Wavelength Assignment Information Encoding for Wavelength Switched Optical Networks", draft-ietf-ccamp- rwa-wson-encode, work in progress. [WSON-OSPF] Lee, Y, Bernstein G., "GMPLS OSPF Enhancement for Signal and Network Element Compatibility for Wavelength Switched Optical Networks", draft-ietf-ccamp-wson-signal- compatibility-ospf, work in progress. [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications", RFC 5511, April 2009. [RFC3209] Awduche, D., et al., "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching Bernstein, et al. Expires September 2015 [Page 13] Internet-Draft WSON Signaling Extensions March 2015 (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. [RFC5420] Farrel, A., Ed., Papadimitriou, D., Vasseur, J.-P., and A. Ayyangar, "Encoding of Attributes for MPLS LSP Establishment Using Resource Reservation Protocol Traffic Engineering (RSVP-TE)", RFC 5420, February 2009. [RSVP-RO] Margaria, C., et al, "LSP Attribute in ERO", draft-ietf- ccamp-lsp-attribute-ro, work in progress. 8.2. Informative References [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC5920, July 2010. [RFC6163] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks", work in progress: draft-bernstein-ccamp-wavelength- switched-03.txt, February 2008. [WSON-Info] G. Bernstein, Y. Lee, D. Li, W. Imajuku, "Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks", work in progress: draft-ietf- ccamp-rwa-info, work in progress. [HZang00] H. Zang, J. Jue and B. Mukherjeee, "A review of routing and wavelength assignment approaches for wavelength-routed optical WDM networks", Optical Networks Magazine, January 2000. 9. Contributors Nicola Andriolli Scuola Superiore Sant'Anna, Pisa, Italy Email: nick@sssup.it Alessio Giorgetti Scuola Superiore Sant'Anna, Pisa, Italy Email: a.giorgetti@sssup.it Bernstein, et al. Expires September 2015 [Page 14] Internet-Draft WSON Signaling Extensions March 2015 Lin Guo Key Laboratory of Optical Communication and Lightwave Technologies Ministry of Education P.O. Box 128, Beijing University of Posts and Telecommunications, P.R.China Email: guolintom@gmail.com Yuefeng Ji Key Laboratory of Optical Communication and Lightwave Technologies Ministry of Education P.O. Box 128, Beijing University of Posts and Telecommunications, P.R.China Email: jyf@bupt.edu.cn Daniel King Old Dog Consulting Email: daniel@olddog.co.uk Authors' Addresses Greg M. Bernstein (editor) Grotto Networking Fremont California, USA Phone: (510) 573-2237 Email: gregb@grotto-networking.com Young Lee (editor) Huawei Technologies 5340 Legacy Dr. Building 3 Plano, TX 75024 USA Phone: (469) 277-5838 Email: leeyoung@huawei.com Sugang Xu National Institute of Information and Communications Technology 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan Phone: +81 42-327-6927 Email: xsg@nict.go.j Giovanni Martinelli Bernstein, et al. Expires September 2015 [Page 15] Internet-Draft WSON Signaling Extensions March 2015 Cisco Via Philips 12 20052 Monza, IT Phone: +39 039-209-2044 Email: giomarti@cisco.com Hiroaki Harai National Institute of Information and Communications Technology 4-2-1 Nukui-Kitamachi, Koganei, Tokyo, 184-8795 Japan Phone: +81 42-327-5418 Email: harai@nict.go.jp Bernstein, et al. Expires September 2015 [Page 16]