Internet Engineering Task Force G. Martinelli, Ed. Internet-Draft Cisco Systems Intended status: Standards Track A. Zanardi, Ed. Expires: May 11, 2008 CREATE-NET November 8, 2007 GMPLS Signaling Extensions for Optical Impairment Aware Lightpath Setup draft-martinelli-ccamp-optical-imp-signaling-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. This Internet-Draft will expire on May 11, 2008. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract The problem of provisioning a light-path in a transparent dense wavelength division multiplexing (DWDM) optical island requires the transmission of optical impairment related parameters along the selected route. In this draft we propose the GMPLS signaling protocol (RSVP/RSVP-TE) extensions to transmit optical impairments to setup an optically feasible light-path. Martinelli & Zanardi Expires May 11, 2008 [Page 1] Internet-Draft Optical Impairment Signaling November 2007 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 3. Optical Path Validation Procedure . . . . . . . . . . . . . . 4 4. Physical Parameter Classification and top level TLV . . . . . 5 5. Optical Service Parameters sub-TLV . . . . . . . . . . . . . . 7 5.1. Forward Error Correction (FEC) . . . . . . . . . . . . . . 8 5.2. Modulation Format . . . . . . . . . . . . . . . . . . . . 8 6. Optical Path Parameters sub-TLV(s) . . . . . . . . . . . . . . 8 6.1. Mandatory Linear Optical Parameters . . . . . . . . . . . 9 6.2. Optional Linear Optical Parameters . . . . . . . . . . . . 10 7. Message Fragmentation . . . . . . . . . . . . . . . . . . . . 11 8. Backward Compatibility . . . . . . . . . . . . . . . . . . . . 14 9. Error management . . . . . . . . . . . . . . . . . . . . . . . 14 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14 11. Contributing Authors . . . . . . . . . . . . . . . . . . . . . 14 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 13. Security Considerations . . . . . . . . . . . . . . . . . . . 16 14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 14.1. Normative References . . . . . . . . . . . . . . . . . . . 16 14.2. Informative References . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . . . . 19 Martinelli & Zanardi Expires May 11, 2008 [Page 2] Internet-Draft Optical Impairment Signaling November 2007 1. Introduction The current Generalized Multi-Protocol Label Switching (GMPLS) specification [RFC3945] and the signalling related documents ([RFC3471], [RFC3473], [RFC4328]) support optical interfaces with different switching capability to setup a light-path while [RFC4054] defines routing optical constrains on routing. [I-D.bernstein-ccamp-wavelength-switched], defines a framework for identifying key components and issues pertaining to wavelength switched optical networks (WSON). [I-D.otani-ccamp-gmpls-lambda-labels] propose a global semantic for wavelength generalized labels taking into account light-path specific needs. In transparent optical networks, physical impairments incurred by non-ideal optical transmission medium accumulate along an optical path. Because of these impairments even if two nodes are connected through an optical path, there is no guarantee that the optical signal (light) reaches the end node with acceptable signal quality, for example in terms of BER/OSNR/Q-factor limit. For a successful light-path provisioning in a WSON, the set up process must be aware of a set of physical impairments that has effect on the light-path. A complete set of physical impairments will include linear and non- linear impairments. This preliminary draft proposes a way to collect the optical path linear impairments in the signaling phase by providing suitable extensions to signaling protocol (RSVP/RSVP-TE) assuming that non-linear impairments effects are handled in the network design phase considering a bounded OSNR margin [RFC4054]. The management of physical impairments is done only in the signalling process and it does not require any extension to the traffic engineering database. The set of parameters carried by the signaling protocol is divided into optical service parameters and optical path parameters: o The optical service parameters describe the requested signal type, are related to the characteristics of the transponder at source node and hence are not changed at transit nodes. o The optical path parameters describe the signal characteristics evolution along the path from source node to destination node, are related to the characteristics of the various links/subsystems and are updated at each transit node. They are divided into mandatory and optional parameters. The mandatory parameters are related to feasibility constraints such as power and OSNR, whereas the optional parameters are extendable linear impairments such as chromatic dispersion (CD), polarization mode dispersion (PMD), Martinelli & Zanardi Expires May 11, 2008 [Page 3] Internet-Draft Optical Impairment Signaling November 2007 crosstalk, etc. The optional parameters can be used to evaluate the feasibility of a light-path more accurately as an alternate solution to the bounded OSNR margin evaluation. Parameter update methods might use appropriate physical models and are out of scope of this document. 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]. In additions this document will use terminology from [RFC2205], [RFC3209], [RFC4054], and [I-D.bernstein-ccamp-wavelength-switched]. 3. Optical Path Validation Procedure The signaling based validation of an optical path in downstream direction in a transparent network (lambda switched LSP) is implemented by the following procedure: o The source node signals in the Path message the supported signal types (FEC and modulation format) and wavelength set (encoded in the LABEL_SET Object) depending on available local transponders. o Transit nodes update the Path message pruning non cross- connectable wavelengths (LABEL_SET Object) and computing or measuring the path optical characteristics up to the outgoing interface (optical impairments). o Destination node selects the wavelength and the signal type based on the signaled optical impairments and the available local transponders (supported wavelengths, sensitivity to optical impairments) and signals the selection in the Resv message. o Intermediate nodes process the Resv message cross-connecting the selected wavelength in incoming and outgoing ports (wavelength continuity constraint). o The source node cross-connects the selected wavelength to a local transponder supporting the selected signal type (FEC and modulation format). The unavailability of cross-connectable wavelength in intermediate nodes or of transponders supporting the signal in the destination node causes the request failure (PathErr message). Martinelli & Zanardi Expires May 11, 2008 [Page 4] Internet-Draft Optical Impairment Signaling November 2007 The unavailability of the selected wavelength in intermediate nodes or of transponders supporting the signal in the source node (race condition in allocating resources) causes the request failure (ResvErr message). In this document, only the encoding in the RSVP messages of the optical information needed to support the described procedure is defined. The specific policies used to select the resources (wavelength and transponders), the models to compute the optical impairments and the procedure to validate the signal with respect to the transponder sensitivity are not in the scope of this document. 4. Physical Parameter Classification and top level TLV The extensions required to RSVP/RSVP-TE to make them aware of optical impairments and to setup optically feasible light-paths requires the following information: o Optical Service Parameters. The standard GENERALIZED_LABEL_REQUEST and TSPEC/FLOW_SPEC objects support the encoding of the information related to service type and service QoS. However for DWDM networks the end node of an LSP has to know a certain set of specific optical parameters related to transmitting interface. Section 5 reports details of these parameters and their encoding. o Optical Path Parameters. These attributes are required to support transmission of physical impairment parameters required for the optical path feasibility evaluation. Details are presented in Section 6. This document defines how to encode the above information through new TLVs according to [RFC4420]. The proposed encoding scheme for the optical parameters defines a TLV (channel optical physical information) associated to a wavelength and a set of sub-TLV for each set of service and path parameters. Additional set of parameters can be added without affecting the already defined encoding. A TLV sub-object for each available wavelength (PATH message) or selected wavelength (RESV message) is encoded in an LSP_REQUIRED_ATTRIBUTES Object. The TLV sub-object encoding is defined in the next picture. Martinelli & Zanardi Expires May 11, 2008 [Page 5] Internet-Draft Optical Impairment Signaling November 2007 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 ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // Parameters Sub-TLV Sequence // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 Type: optical channel physical parameters info TLV type (TBA). Length: length of the TLV object in bytes without the 4 byte header. Wavelength ID: wavelength label identifier according to [I-D.otani-ccamp-gmpls-lambda-labels]. Parameters Sub-TLV Sequence: service and path parameters values. The Sub-TLV format is defined in the next picture 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 | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // Value // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 Type: Sub-TLV type Flags: bit-mask defining the management of the Sub-TLV bit 0: Mandatory if set, Optional if unset bit 1: ToUpdate if set, Constant if unset bit 2-7: to be assigned Martinelli & Zanardi Expires May 11, 2008 [Page 6] Internet-Draft Optical Impairment Signaling November 2007 Length: Value field length in bytes Value: variable length Sub-TLV content The Flags field defines how intermediate nodes manage unrecognized Sub-TLV: Unrecognized Constant sub-TLVs are forwarded as-is Unrecognized Mandatory and ToUpdate sub-TLVs cause the reject with a failure of the request Unrecognized Optional and ToUpdate sub-TLVs are silently dropped from the TLV (the value would be inaccurate) 5. Optical Service Parameters sub-TLV The Optical Service Parameters defines the signal transmissions characteristics at the source node. This type of information is required at the destination node to verify the optical signal compatibility. 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 | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FEC 1 | Mod Format 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FEC n | Mod Format n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3 Type: sub-TLV type (=1) Flags: Mandatory, Constant Length: length of the sub-TLV value in bytes FEC: supported Forward Error Correction Modes (see Section 5.1 Mod Format: supported modulation formats (see Section 5.2) associated with the FEC. Martinelli & Zanardi Expires May 11, 2008 [Page 7] Internet-Draft Optical Impairment Signaling November 2007 This sub-TLV is used in the PATH message to signal the full list of optical parameters associated with physical interfaces (signal types and wavelengths) available at the source node. In the RESV message this information is associated to the selected receiving interface at the destination node. In the RESV message only one tuple (FEC, Mod Format) will be specified. 5.1. Forward Error Correction (FEC) FEC (16 bits) field is the Forward Error Correction and has the following values: 0: no FEC 1: standard FEC (according to [ITU.G709]) 2-9: super-FEC according to sub clauses from I.2 to I.9 of [ITU.G975.1] Values of the format 1bbb.bbbb.bbbb.bbbb are left to represent vendor specific or proprietary FEC encoding. 5.2. Modulation Format Mod Format (16 bits) is the available modulation format at the source node. Currently the field takes the following values: 0: NRZ 1: Duo Binary 2: DPSK Other values might be defined in the future as technology advance. Also here values with the format 1bbb.bbbb.bbbb.bbbb are left to represent vendor specific or proprietary modulation formats. 6. Optical Path Parameters sub-TLV(s) For each available channel, this set of parameters has to be carried through the PATH message to allow the optical feasibility evaluation. At each hop, the optical node will update these values according to information locally available at the node (say internal amplifiers, wavelength cross connect, etc.). The way an optical node gets knowledge of this required information (e.g. through NMS, auto- discovery etc.) is out of the scope of this document. Martinelli & Zanardi Expires May 11, 2008 [Page 8] Internet-Draft Optical Impairment Signaling November 2007 This document defines two groups of linear optical parameters. Each group will have its own sub-TLV. Mandatory Linear Optical Parameters This set includes Optical Signal Power and the OSNR with associated variances. It represents a minimum set to asses the feasibility of an optical path. This set will be encoded using a mandatory sub-TLV. Optional Linear Optical Parameters This set includes CD, PMD, XT with associated variances. These parameters represent an additional set to allow a more accurate optical feasibility evaluation. This set will be encoded using an optional sub-TLV. Separation between Mandatory and Optional allows a rough optical feasibility evaluation where network elements support at least the Mandatory set. Depending on how a WSON is designed, the usage of the mandatory set could be an operational choice not to overwhelm the control plane while maintaining reliable feasibility estimation. Moreover it might happens that not all nodes in a networks support both sets of optical path parameters. With this separation, the light-path signalling still continues to work with a less accurate evaluation. The choice of optional set of parameters depends on several considerations. They are among those reported by the [RFC4054] and provide sufficient accuracy for the linear impairments evaluation. For each parameter an error estimation is associated (variance); if no error estimation is provided the value MUST be zero. 6.1. Mandatory Linear Optical Parameters The Sub-TLV encode the values of the optical parameters of the channel (wavelength) associated to the TLV, measured at the node egress interface. Martinelli & Zanardi Expires May 11, 2008 [Page 9] Internet-Draft Optical Impairment Signaling November 2007 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 | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Optical Power | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Signal Optical Power Variance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OSRN | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OSNR Variance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4 Type: sub-TLV type (TBA). Flags: Mandatory, ToUpdate. Length: length of the sub-TLV value in bytes. Signal Optical Power. 32-bit IEEE floating point number. Measurement Unit: dBm. Signal Optical Power Variance. 32-bit IEEE floating point number. OSNR. 32-bit IEEE floating point number. Measurement Unit: dB. OSNR Variance. 32-bit IEEE floating point number. 6.2. Optional Linear Optical Parameters The Sub-TLV encode the values of the optional optical parameters of the channel (wavelength) associated to the TLV, measured at the node egress interface. This Sub_TLV is defined as LSP_ATTRIBUTES. Martinelli & Zanardi Expires May 11, 2008 [Page 10] Internet-Draft Optical Impairment Signaling November 2007 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 | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CD | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CD Variance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PMD | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PMD Variance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CrossTalk | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CrossTalk Variance | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5 Type: sub-TLV type (TBA). Flags: Optional, ToUpdate. Length: length of the sub-TLV value in bytes. CD, Chromatic Dispersion. 32-bit IEEE floating point number. Measurement Unit: ps/nm. CD Variance. 32-bit IEEE floating point number. PMD, Polarization Mode Dispersion. 32-bit IEEE floating point number. Measurement Unit: ps. PMD Variance. 32-bit IEEE floating point number. CrossTalk. 32-bit IEEE floating point number. Measurement Unit: dB. CrossTalk Variance. 32-bit IEEE floating point number. 7. Message Fragmentation In certain cases, the state information carried by the Path message can be quite large. Size estimation for a physical Optical Channel TLV (see Figure 1) can be the following: 8 bytes for type, length and wavelength ID plus, 16 bytes for the Optical Service Parameters sub- Martinelli & Zanardi Expires May 11, 2008 [Page 11] Internet-Draft Optical Impairment Signaling November 2007 TLV considering 3 FEC/modulation format combinations plus, 20 bytes for the Mandatory Linear Optical Path parameters plus 28 bytes for the Optional Linear Optical Parameter sub-TLV. Total is 44 bytes for each wavelength by just considering mandatory sub-TLVs and 72 bytes by considering also the optional part. Given the number of wavelengths today available in DWDM networks, the size of the path message end up in large values. For example to signal just 32 wavelengths the size required for the physical optical parameters ranges at least from 1408 to 2304 bytes. One possible option is to let the application layer requesting the light-path setup to decide how many wavelengths to signal. So, for example, the application layer might ask to signal at most 10 wavelengths at a time to make sure the path message will stay within the MTU limit for its network. A second solution proposed here allows the semantic fragmentation as suggested by RSVP [RFC2205]. The proposed encoding extends the SENDER_TEMPLATE with new ClassType (derived from the LSP_TUNNEL_IPv4 and LSP_TUNNEL_IPv6 RSVP-TE [RFC3209]). The Object includes the information on the "fragment id" and the requested policy at the destination node Class = SENDER_TEMPLATE, FRAGREQ_LSP_TUNNEL_IPv4 C-Type = TBA 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 tunnel sender address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TotalNo | MsgId | P | Timeout | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6 Martinelli & Zanardi Expires May 11, 2008 [Page 12] Internet-Draft Optical Impairment Signaling November 2007 Class = SENDER_TEMPLATE, FRAGREQ_LSP_TUNNEL_IPv6 C-Type = TBA 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | IPv6 tunnel sender address | + + | (16 bytes) | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TotalNo | MsgId | P | Timeout | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7 Besides fields already defined in the SENDER_TEMPLATE, the following fields are defined here: o TotalNo: 8 bit integer representing the total number of Path messages issued by the source node to setup a single light-path. When this values is equals to 1 all the other fields MUST be ignored. o MsgId: 8 bit integer representing a sequential number of a single Path request. Its value must be between 1 and TotalNo, both inclusive. o P: Policy the destination node must apply upon receiving a fragmented path request: 1: Take the first message arrived and ignore the following ones. 2: After the first message arrived, wait for any messages within the specified Timeout. 3: After the first message arrived, waits for all messages. Fail, if the timeout expires, and there's at least one message missing The Destination node should "reject" (PathERR) all the requests except for the selected one, even if it could rely on the RSVP timeout to clear the unselected requests status in intermediate Martinelli & Zanardi Expires May 11, 2008 [Page 13] Internet-Draft Optical Impairment Signaling November 2007 nodes. o Timeout: 12 bits integer number representing the timeout value used by the policy. The value is in s/100 (hundreds of seconds) All messages MUST have the same value. This type of encoding is a generic solution to manage the semantic fragmentation and its not strictly related to optical parameters encoding. 8. Backward Compatibility The TLV usage as defined by [RFC4420] will guarantee the co-existence of nodes supporting normal RSVP-TE operations and node with optical impairment signaling capability. A service with the new feature (optical feasibility evaluation) can be setup only if all the nodes in the path support the extensions. Optical Path Parameters are updated hop-by-hop and evaluated at destination node. If an intermediate node does not support the extensions the collected information is unreliable and the Path request MUST be rejected. 9. Error management No additional error code is introduced to manage requests failures; the behavior defined in [RFC4420] applies to the management of the LSP_REQUIRED_ATTRIBUTES Object. 10. Acknowledgements 11. Contributing Authors This document was the collective work of several authors. The text and content of this document was contributed by the editors and the co-authors listed below (the contact information for the editors appears in appropriate section and is not repeated below): Martinelli & Zanardi Expires May 11, 2008 [Page 14] Internet-Draft Optical Impairment Signaling November 2007 Gabriele Maria Galimberti Alberto Tanzi Cisco Systems Cisco Systems via Philips 12 via Philips 12 Monza 20052 Monza 20052 Italy Italy Email: ggalimbe@cisco.com Email: atanzi@cisco.com Domenico La Fauci Stefano Piciaccia Cisco Systems Cisco Systems via Philips 12 via Philips 12 Monza 20052 Monza 20052 Italy Italy Email: dlafauci@cisco.com Email: spiciacc@cisco.com Elio Salvadori Yabin Ye CREATE-NET CREATE-NET via della Cascata 56c, Povo via della Cascata 56c, Povo Trento 38100 Trento 38100 Italy Italy Email: elio.salvadori@create-net.org Email: yabin.ye@create-net.org Chava Vijaya Saradhi CREATE-NET via della Cascata 56c, Povo Trento 38100 Italy Email: saradhi.chava@create-net.org 12. IANA Considerations This memo needs the follwing request to IANA TLV (see Figure 1 in Section 4) New class type for sender template (see Section 7) All drafts are required to have an IANA considerations section (see the update of RFC 2434 [I-D.narten-iana-considerations-rfc2434bis] Martinelli & Zanardi Expires May 11, 2008 [Page 15] Internet-Draft Optical Impairment Signaling November 2007 for a guide). If the draft does not require IANA to do anything, the section contains an explicit statement that this is the case (as above). If there are no requirements for IANA, the section will be removed during conversion into an RFC by the RFC Editor. 13. 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. 14. References 14.1. Normative References [ITU.G709] International Telecommunications Union, "Interface for the Optical Transport Network (OTN)", ITU-T Recommendation G.709, March 2003. [ITU.G975.1] International Telecommunications Union, "Forward Error Correction for high bit rate DWDM Submarine Systems", ITU- T Recommendation G.975, February 2004. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 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 (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Martinelli & Zanardi Expires May 11, 2008 [Page 16] Internet-Draft Optical Impairment Signaling November 2007 Transport Networks Control", RFC 4328, January 2006. [RFC4420] Farrel, A., Papadimitriou, D., Vasseur, J., and A. Ayyangar, "Encoding of Attributes for Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) Establishment Using Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)", RFC 4420, February 2006. 14.2. Informative References [I-D.bernstein-ccamp-wavelength-switched] Bernstein, G., "Framework for GMPLS and PCE Control of Wavelength Switched Optical Networks", draft-bernstein-ccamp-wavelength-switched-02 (work in progress), October 2007. [I-D.narten-iana-considerations-rfc2434bis] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", draft-narten-iana-considerations-rfc2434bis-08 (work in progress), October 2007. [I-D.otani-ccamp-gmpls-lambda-labels] Otani, T., "Generalized Labels of Lambda-Switching Capable Label Switching Routers (LSR)", draft-otani-ccamp-gmpls-lambda-labels-00 (work in progress), July 2007. [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [RFC4054] Strand, J. and A. Chiu, "Impairments and Other Constraints on Optical Layer Routing", RFC 4054, May 2005. Authors' Addresses Giovanni Martinelli (editor) Cisco Systems via Philips 12 Monza 20052 Italy Email: giomarti@cisco.com Martinelli & Zanardi Expires May 11, 2008 [Page 17] Internet-Draft Optical Impairment Signaling November 2007 Andrea Zanardi (editor) CREATE-NET via della Cascata 56c, Povo Trento 38100 Italy Email: andrea.zanardi@create-net.org Martinelli & Zanardi Expires May 11, 2008 [Page 18] Internet-Draft Optical Impairment Signaling November 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property 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. 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Martinelli & Zanardi Expires May 11, 2008 [Page 19]