Internet Engineering Task Force G. Galimberti, Ed. Internet-Draft D. La Fauci Intended status: Experimental Cisco Expires: May 7, 2020 A. Zanardi, Ed. L. Galvagni FBK-CreateNet November 4, 2019 Signaling extensions for Media Channel sub-carriers configuration in Spectrum Switched Optical Networks (SSON) in Lambda Switch Capable (LSC) Optical Line Systems. draft-ggalimbe-ccamp-flexigrid-carrier-label-08 Abstract This memo defines the signaling extensions for managing Spectrum Switched Optical Network (SSON) parameters shared between the Client and the Network and inside the Network in accordance to the model described in RFC 7698. The extensions are in accordance and extending the parameters defined in ITU-T Recommendation G.694.1.[ITU.G694.1] and its extensions and G.872.[ITU.G872]. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on May 7, 2020. Galimberti, et al. Expires May 7, 2020 [Page 1] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Copyright Notice Copyright (c) 2019 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 (https://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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Client interface parameters . . . . . . . . . . . . . . . . . 3 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Signalling Extensions . . . . . . . . . . . . . . . . . . . . 5 4.1. New LSP set-up parameters . . . . . . . . . . . . . . . . 5 4.2. Extension to LSP set-up reservation . . . . . . . . . . . 7 4.2.1. Sub-carrier list content . . . . . . . . . . . . . . 9 4.2.2. Sub-carrier sub-TLV . . . . . . . . . . . . . . . . . 11 4.3. RSVP Protocol Extensions considerations . . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 15 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . 15 8.2. Informative References . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction Generalised Multiprotocol Label Switched (GMPLS) is widely used in Wavelength Switched Optical Network (WSON) to support the optical circuits set-up through the signalling between Core Nodes and Edge Nodes. This extension addresses the use cases described by [RFC7698] Ch.3.3 and supports the information, needed in Spectrum Switched Optical Network (SSON), to signal a Media Channel and the associated carriers set request. The new set of parameters is related to the Media Channel and the carrier(s) routed with it and keep the backward compatibility with the WSON signalling. In particular this memo wants do address the use cases where the SSON LSP (the Media Channel in RFC7698) carries multiple carrier (OTSi) containing same Payload. The set of the carriers can be seen as single Logical circuit. This Galimberti, et al. Expires May 7, 2020 [Page 2] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 memo can be considered as the extension of [RFC7792]. The contents and the parameters reflect the experimental activity on IP over SSON recently done by some vendors and research consortia. Figure 1 shows how the multiple carrier are mapped into a Media Channel. A set of parameters must be shared on the UNI to allow the GMPLS to do the proper routing and Spectrum Assignment and decide the carrier position. +------+ +------+ _________ +------+ +------+ | E.N. | | C.N. | / /\ | C.N. | | E.N. | | OTS1| ----- | || | || | ----- |OTS1 | ==| OTS2| ----- | || Media | || | ----- |OTS2 |== ==| OTS3| ----- | || Channel| || | ----- |OTS3 |== | OTS4| ----- | || | || | ----- |OTS4 | | | | ROADM| \________\/ | ROADM| | | +------+ +------+ +------+ +------+ ^ ^ ^ ^ | | | | +---UNI---+ +---UNI---+ E.N. = Edge Node - UNI Client C.N. = Core Node - UNI Network ROADM = Lambda/Spectrum switch Media Channel = the optical circuit OTSi = Carriers belonging to the same Network Media Channel (or Super Channel) UNI = Signalig interface Figure 1: Multi carrier LSP 2. Client interface parameters The Edge Node interface can have one or multiple carriers (OTSi). All the carrier have the same characteristics and are provisionable in terms of: Number of subcarriers: This parameter indicates the number of subcarriers (OTSi) available for the super-channel (OTSiG) in case the Transceiver can support multiple carrier circuits. The OTSi is defined in ITU-T Recommendation G.959.1, section 3.2.4 [G.959.1]. The OTSiG is currently being moved from ITU-T Recommendation G.709 [G.709] to the new draft Recommendation G.807 (still work in progress) [G.807]. The OTSiG is an electrical signal that is carried by one Galimberti, et al. Expires May 7, 2020 [Page 3] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 or more OTSi's. The relationship between the OTSiG and the the OTSi's is described in ITU-T draft Recommendation G.807, section 10.2 [G.807]. Central frequency (see G.694.1 Table 1): This parameter indicates the Central frequency value that Ss and Rs will be set to work (in THz). See the details in Section 6/ G.694.1 or based on "n" value explanation and the following "k" values definition in case of multicarrier transceivers. Central frequency granularity: This parameter indicates the Central frequency granularity supported by the transceiver, this value is combined with k and n value to calculate the central frequency of the carrier or sub- carriers. Minimum channel spacing: This is the minimum nominal difference in frequency (in GHz) between two adjacent channels (or carriers) depending on the Transceiver characteristics. Bit rate / Baud rate of optical tributary signals: Optical Tributary Signal bit (for NRZ signals) rate or Symbol (for Multiple bit per symbol) rate . FEC Coding: This parameter indicate what Forward Error Correction (FEC) code is used at Ss and Rs (R/W) (not mentioned in G.698.2). . Wavelength Range (see G.694.1): [ITU.G694.1] This parameter indicate minimum and maximum wavelength spectrum in a definite wavelength Band (L, C and S). Modulation format: This parameter indicates the list of supported Modulation Formats and the provisioned Modulation Format. Inter carrier skew: This parameter indicates, in case of multi-carrier transceivers the maximum skew between the sub-carriers supported by the transceiver. Laser Output power: This parameter provisions the Transceiver Output power, it can be either a setting and measured value. Receiver input power: Galimberti, et al. Expires May 7, 2020 [Page 4] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 This parameter provisions the Min and MAX input pover suppotred by the Transceiver, i.e. Receiver Sensitivity. The above parameters are related to the Edge Node Transceiver and are used by the Core Network GMPLS in order to calculate the optical feasibility and the spectrum allocation. The parameters can be shared between the Client and the Network via LMP or provisioned to the Network by an EMS or an operator OSS. 3. Use Cases The use cases are described in draft-ietf-ccamp-dwdm-if-mng-ctrl-fwk and [RFC7698] 4. Signalling Extensions Some of the above parameters can be applied to RFC7792 (SENDER_TSPEC/ FLOWSPEC). The above parameters could be applied to [RFC4208] scenarios but they are valid also in case of non UNI scenarios. The [RFC6205] parameters remain valid. 4.1. New LSP set-up parameters When the E.N. wants to request to the C.N. a new circuit set-up request or the GMPLS wants to signal in the SSON network the Optical Interface characteristics the following parameters will be provided to the C.N.: Number of available subcarriers (c): This parameter is an integer and identifies the number of Client ports connected to the Core ports available to suport the requested circuit, this identify also the number of OTSi in an OTSiG. Total bandwidth request: e.g. 200Gb, 400Gb, 1Tb - it is the bandwidth (payload) to be carried by the multiple carrier circuit (OTSiG). In alternative the OTUCn can be used Policy (strict/loose): Strict/loose referred to B/W and subcarrier number. This is to give some flexibility to the GMPLS in order to commit client request. Subcarrier bandwidth tunability: (optional) e.g. 34Ghz, 48GHz. Galimberti, et al. Expires May 7, 2020 [Page 5] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 The TLV define the resource constraints for the requested Media Channel. The format of the this sub-object is as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |S|B| Reserved | Carrier Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Total Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: SSON LSP set-up request Carrier Number: number of carrier to be allocated for the requested channel (16-bit unsigned integer) If Carrier Number == 0 no constraint set on the number of carriers to be used S strict number of subcarrier - S = 0 the number of requested carriers is the maximum number that can be allocated (a lower value can be allocated if the requested bandwidth is satisfied) - S = 1 the number of requested carriers is strict (must be > 0) Total Bandwidth: the requested total bandwidth to be supported by the Media Channel (32-bit IEEE float, bytes/s) If Total Bandwidth == 0: no bandwidth constraint is defined (B must be 0) B Bandwidth constraints - B = 0: the value is the maximum requested bandwidth (a lower value can be allocated if resources are not available) - B = 1: the requested bandwidth is the minimum value to be allocated (a higher value can be allocated if requested by the physical constraints of the ports) Reserved: unused bit (for future use, should be 0) Galimberti, et al. Expires May 7, 2020 [Page 6] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Note: bandwidth unit is defined in accordance to RFC 3471 chap. 3.1.2 Bandwith Encoding specification. Bandwidth higher than 40Gb/s values must be defined (e.g. 100Gb/s, 150Gb/s 400Gb/s, etc.) or in alternative the OTUCn defined in ITU-T G.709. TLV Usage: Head UNI-C PATH: requested traffic constraints, the Head UNI-N node must satisfy when reserving the optical resources and defining the carriers configuration The TLV can be omitted: no traffic constraints is defined (resources allocated by UNI-N based on a local policy) 4.2. Extension to LSP set-up reservation Once the GMPLS has calculated the Media Channel path, the Spectrum Allocation, the Sub-carrier number and frequency, the modulation format, the FEC and the Transmit power, sends back to the E.N. the path set-up confirmation providing the values of the calculated paramenters: Media Channel: (Grid, C.S., Identifier m and n). as indicated in RFC7699 Section 4.1 Modulation format: This parameter indicates the Modulation Formats to be set in the Transceivers. FEC Coding: This parameter indicate what Forward Error Correction (FEC) code must be used by the Transceivers (not mentioned in G.698). . Bit rate / Baud rate of optical tributary signals: Optical Tributary Signal bit (for NRZ signals) rate or Symbol (for Multiple bit per symbol) rate. List of subcarriers: This parameter indicates the subcarriers to be used for the super- channel (OTSiG) in case the Transceiver can support multiple carrier Circuits. Central frequency granularity (J): This parameter indicates the Central frequency granularity supported by the transceiver, this value is combined with K and n value to calculate the central frequency on the carrier or sub- carriers. Galimberti, et al. Expires May 7, 2020 [Page 7] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Central frequency (see G.694.1 Table 1): Grid, Identifiers, central frequency and granularity. Laser Output power: This parameter provisions the Transceiver Output power, it can be either a setting and measured value. Circuit Path, RRO, etc: All these info are defined in [RFC4208]. Path Error: e.g. no path exist, all the path error defined in [RFC4208]. The TLV defines the carriers signal configuration. All carriers in a Media Channel MUST have the same configuration. The format of this sub-object (Type = TBA, Length = TBA) is as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Modulation ID | Bit/Symbol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | FEC | reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | baud rate (Symbol Rate) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: OCh_General Galimberti, et al. Expires May 7, 2020 [Page 8] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Traffic Type - Modulation ID (Format) : is the modulation type: BPSK, DC DP BSPSK, QPSK, DP QPSK, 8QAM, 16QAM, 32QAM, 64QAM, etc. - (ITU-T reference) - Value > 32768 (first bit is 1): custom defined values - Value 0 is reserved to be used if no value is defined - Bits/Symbol(BPS) this indicates the bit per symbol in case of hybrid modulation format. It is an off-set with values from 0 to 127 to be applied to the specified Modulation Format and indicates the mix between the selected Modulation Format and its upper adjacent. (e.g. QPSK + 63 BPS indicates that there is a 50% MIX between QPSK and 8-QAM = 2.5 bits per symbol) If value = 0 the standard Modulation Format is applied - FEC: the signal Forward Error Corrections type (16-bit unsigned integer), the defined values are: - 1 to 32767 (ITU-T reference) - 32768 to 65536 (first bit is 1): custom defined values - Value 0 is reserved to be used if no value is defined - Baud Rate: the signal symbol rate (IEEE 32-bit float, in bauds/s) - Value 0 is reserved to be used if no value is defined Notes: - The PATH request from the Head UNI-C node can specify all or only a subset of the parameters (e.g. the Modulation and the baud rate as required but not the FEC) setting to 0 for the undefined parameters. When forwarding the PATH message, the UNI-N will set the undefined parameters based on the optical impairment calculation and the constraints giveng by the UNI-C - Custom codes (values > 0x8000) interpretation is a local installation matter. TLV Usage: - Head UNI-C PATH: used to force specific transponder configurations - Head UNI-N RESV: set selected configuration on head node - Tail UNI-N PATH: set selected configuration on tail node 4.2.1. Sub-carrier list content Galimberti, et al. Expires May 7, 2020 [Page 9] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 For Each carrier inside the Media Channel the TLV is used. The format of this sub-object (Type = TBA, Length = TBA) is as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Carrier Identifier | j | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | k | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-TLVs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Sub-Carrier parameters Galimberti, et al. Expires May 7, 2020 [Page 10] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Carrier set-up: - Carrier identifier field: sub-carrier (OTSi) identifier inside the OTSiG (corresponding to the media channel). Identifies the carrier position inside the Media Channel (16-bit unsigned integer) The Carrier Identifier is the logical circuit sub-lane position, a TLV for each value from 1 to the number of allocated carriers must be present. - J field: granularity of the channel spacing, can be a multiple of 0.01GHz. - default value is 0.1GHz. - K field: positive or negative integer (including 0) to multiply by J and identify the Carrier Position inside the Media Channel, offset from media Channel Central frequency - sub-TLVs: additional information related to carriers if needed and the ports associated to the carrier. In summary Carrier Frequency = MC-C.F. (in THz) + K * J GHz. m=8 +-------------------------------X------------------------------+ | | | | sub-carrier sub-carrier | | +----------X----------+ | +----------X----------+ | | | OTSi | | OTSi | | | | o | | | o | | | | | | | | | | -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 -+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+- | n=4 | K1 -236 | +236 K2 <------------------------ Media Channel -----------------------> 4.2.2. Sub-carrier sub-TLV The defined sub-TLVs are Port Identifiers and Carrier Power Galimberti, et al. Expires May 7, 2020 [Page 11] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Source Port Identifier The format of this sub-object (Type = TBA, Length = TBD) is as follows: 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 (TBA) | Length (TBD) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Port Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Source Port Identifier Source Port Identifier: the HEAD UNI-C optical logical source end point identifier (32-bits integer, ifindex) TLV Usage: - Head UNI-C PATH: used to force specific carrier ports [optional use, e.g. with external PCE scenario] - Tail UNI-N PATH: report selected arrier head ports to tail UNI-C - RESV: report selected configuration to HEAD UNI-C node Destination Port Identifier The format of this sub-object (Type = TBA, Length = TBD) is as follows: 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 (TBA) | Length (TBD) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Port Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Destination Port Identifiers Galimberti, et al. Expires May 7, 2020 [Page 12] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Destination Port Identifier: the local upstream optical logical destination end point identifier (32-bits integer, ifindex) TLV Usage: - Head UNI-C PATH: used to force specific carrier ports [optional use, e.g. with external PCE scenario] - Tail UNI-N PATH: set selected configuration on tail node - RESV: report selected configuration to HEAD UNI-C node Carrier Power The format of this sub-object (Type = TBA, Length = TBD) is as follows: 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 (TBA) | Length (TBD) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | carrier power | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Carrier Power Carrier Power: the requested carrier transmit power (32-bits IEEE Float, dBm), optionally used to notify the configured power (in UNI client side) or force the power to the to the UNI client). TLV Usage: - Head UNI-C PATH: used to force specific carrier frequency/ports (optional use, e.g. with external PCE scenario) - Head UNI-N RESV: set selected configuration on head node - Tail UNI-N PATH: set selected configuration on tail node 4.3. RSVP Protocol Extensions considerations The additional information described in the draft, is related to the Media Channel supported traffic. It could be encoded in the SENDER_TSPEC/FLOW_SPEC objects by extending the SSON_SENDER_TSPEC/ SSON_FLOW_SPEC defined in RFC 7792 (or defining a new C-Type) with an optional TLV list or it could be encoded in a newly defined entry (new OBJECT or new LSP_ATTRIBUTES OBJECT TLV) This solution is consistent with other technology specific extensions (e.g. SDH), but requires the explicit handling of the extensions by all nodes. Galimberti, et al. Expires May 7, 2020 [Page 13] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Beside this, some of the additional information defined is local to the head/tail UNI link (e.g. the carrier/port association), while the traffic spec info should be valid end-to-end. There can be different methods to model and signal the carriers as described in draft-lee-ccamp-optical-impairment-topology-yang. The Media Channel, Network Media Channel and lables are well modelled by the RFC7698, RFC7699 and RFC7792 reflecting the ITU-T Recommendations G.694.1 and G.698.2. Some work is in progress in ITU-T SG15/Q12 to define Network Media Channel (group) that is capable of accommodating the optical tributary signals (OTSi) belonging to optical tributary signal group (OTSiG) (see new ITU-T Draft Recommendation G.807). Currently, no models exist (in the IETF nor ITU-T SG15) that define how the optical tributary signals are described inside the Network Media Channel Group in terms of OTSi identifier, OTSi carrier frequency and OTSi signal width. Other the encoding proposal reported in this draft, there are several at least two other methods to describe the parameters. An option is to describe the OTSi carrier frequency relative to the anchor frequency 193.1THz based on a well-defined granularity (e.g. OTSi carrier frequency = 193100 (GHz) + K * granularity (GHz) where K is a signed integer value). A second option is to explicitly describe the OTSi carrier frequency and the OTSi signal width in GHz with a certain accuracy. The second option which is independent of the n, m values already defined in ITU-T Recommendation G.694.1. The OTSi carrier frequency is described in GHz with 3 fractional digits (decimal 64 fraction digits 3). The OTSi signal width is described in GHz with 3 fractional digits (decimal 64 fraction digits 3) and includes the signal roll off as well as some guard band. The accuracy of 0.001 GHz does not impose a requirement on the optical transceiver components (optical transmitter) in terms of carrier frequency tunability precision. Today's components typically provide a tunability precision in the range of 1..1.5GHz (carrier frequency offset compared to the configured nominal carrier frequency). Future components may provide a better precision as technology evolves. If needed, a controller may retrieve the transceiver properties in terms of carrier frequency tunability precision in order to be capable of properly configuring the underlying transceiver. NOTE FROM THE EDITORS: As this description is arbitrarily proposed by the authors to cover a lack of information in IETF and ITU-T, a Galimberti, et al. Expires May 7, 2020 [Page 14] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 liaison request to ITU-T is needed. The authors are willing to contribute to Liaison editing and to consider any feedback and proposal from ITU-T. 5. Security Considerations GMPLS message security uses IPsec, as described in xxxx. This document only defines new UNI objects that are carried in existing UNI messages, similar to the UNI objects in xxx. This document does not introduce new security considerations. 6. IANA Considerations T.B.D. 7. Contributors Antonello Bonfanti Cisco Via Santa Maria Molgora, 48 c 20871 - Vimercate (MB) Italy abonfant@cisco.com 8. References 8.1. Normative References [ITU.G694.1] International Telecommunications Union, ""Spectral grids for WDM applications: DWDM frequency grid"", ITU-T Recommendation G.698.2, February 2012. [ITU.G698.2] International Telecommunications Union, "Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces", ITU-T Recommendation G.698.2, November 2009. [ITU.G709] International Telecommunications Union, "Interface for the Optical Transport Network (OTN)", ITU-T Recommendation G.709, June 2016. Galimberti, et al. Expires May 7, 2020 [Page 15] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 [ITU.G872] International Telecommunications Union, "Architecture of optical transport networks", ITU-T Recommendation G.872, January 2017. [ITU.G874.1] International Telecommunications Union, "Optical transport network (OTN): Protocol-neutral management information model for the network element view", ITU-T Recommendation G.874.1, November 2016. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions", RFC 3473, DOI 10.17487/RFC3473, January 2003, . [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, DOI 10.17487/RFC3945, October 2004, . [RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter, "Generalized Multiprotocol Label Switching (GMPLS) User- Network Interface (UNI): Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Support for the Overlay Model", RFC 4208, DOI 10.17487/RFC4208, October 2005, . [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010, . [RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, DOI 10.17487/RFC6163, April 2011, . [RFC6205] Otani, T., Ed. and D. Li, Ed., "Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers", RFC 6205, DOI 10.17487/RFC6205, March 2011, . Galimberti, et al. Expires May 7, 2020 [Page 16] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 [RFC7698] Gonzalez de Dios, O., Ed., Casellas, R., Ed., Zhang, F., Fu, X., Ceccarelli, D., and I. Hussain, "Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 7698, DOI 10.17487/RFC7698, November 2015, . [RFC7699] Farrel, A., King, D., Li, Y., and F. Zhang, "Generalized Labels for the Flexi-Grid in Lambda Switch Capable (LSC) Label Switching Routers", RFC 7699, DOI 10.17487/RFC7699, November 2015, . [RFC7792] Zhang, F., Zhang, X., Farrel, A., Gonzalez de Dios, O., and D. Ceccarelli, "RSVP-TE Signaling Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 7792, DOI 10.17487/RFC7792, March 2016, . 8.2. Informative References [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, DOI 10.17487/RFC2629, June 1999, . [RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction and Applicability Statements for Internet- Standard Management Framework", RFC 3410, DOI 10.17487/RFC3410, December 2002, . [RFC4181] Heard, C., Ed., "Guidelines for Authors and Reviewers of MIB Documents", BCP 111, RFC 4181, DOI 10.17487/RFC4181, September 2005, . Authors' Addresses Gabriele Galimberti (editor) Cisco Via S. Maria Molgora, 48 c 20871 - Vimercate Italy Phone: +390392091462 Email: ggalimbe@cisco.com Galimberti, et al. Expires May 7, 2020 [Page 17] Internet-Draftdraft-ggalimbe-ccamp-flexigrid-carrier-label-November 2019 Domenico La Fauci Cisco Via S. Maria Molgora, 48 c 20871 - Vimercate Italy Phone: +390392091946 Email: dlafauci@cisco.com Andrea Zanardi (editor) FBK-CreateNet via alla Cascata 56/D 38123 Povo, Trento Italy Phone: +390461312450 Email: azanardi@fbk.eu Lorenzo Galvagni FBK-CreateNet via alla Cascata 56/D 38123 Povo, Trento Italy Phone: +390461312427 Email: lgalvagni@fbk.eu Galimberti, et al. Expires May 7, 2020 [Page 18]