idnits 2.17.1 draft-wang-ccamp-oducn-fwk-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (October 31, 2016) is 2706 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Missing Reference: 'RFC4328' is mentioned on line 264, but not defined == Missing Reference: 'G709-2012' is mentioned on line 186, but not defined == Missing Reference: 'RFC7062' is mentioned on line 84, but not defined == Missing Reference: 'RFC7096' is mentioned on line 84, but not defined == Missing Reference: 'RFC7138' is mentioned on line 84, but not defined == Missing Reference: 'RFC7139' is mentioned on line 265, but not defined == Missing Reference: 'G709-2016' is mentioned on line 263, but not defined == Missing Reference: 'G.709-2016' is mentioned on line 213, but not defined == Unused Reference: 'G.709' is defined on line 323, but no explicit reference was found in the text == Unused Reference: 'RFC3209' is defined on line 334, but no explicit reference was found in the text == Unused Reference: 'RFC3471' is defined on line 339, but no explicit reference was found in the text == Unused Reference: 'RFC3473' is defined on line 344, but no explicit reference was found in the text == Unused Reference: 'RFC3603' is defined on line 350, but no explicit reference was found in the text == Unused Reference: 'RFC4202' is defined on line 356, but no explicit reference was found in the text == Unused Reference: 'RFC4203' is defined on line 361, but no explicit reference was found in the text == Unused Reference: 'RFC4204' is defined on line 366, but no explicit reference was found in the text == Unused Reference: 'RFC3945' is defined on line 372, but no explicit reference was found in the text ** Obsolete normative reference: RFC 3603 (Obsoleted by RFC 5503) Summary: 1 error (**), 0 flaws (~~), 19 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Engineering Task Force Q. Wang, Ed. 3 Internet-Draft Y. Zhang 4 Intended status: Informational ZTE 5 Expires: May 4, 2017 October 31, 2016 7 GMPLS Routing and Signalling Framework for ODUCn 8 draft-wang-ccamp-oducn-fwk-00 10 Abstract 12 This document provides a framework to address the GMPLS routing and 13 signalling issues to support Generalized Multi-Protocol Label 14 Switching (GMPLS)control of Optical Transport Networks (OTNs) as 15 specified in ITU-T Recommendation G.709 as published in 2016. 17 Status of This Memo 19 This Internet-Draft is submitted in full conformance with the 20 provisions of BCP 78 and BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF). Note that other groups may also distribute 24 working documents as Internet-Drafts. The list of current Internet- 25 Drafts is at http://datatracker.ietf.org/drafts/current/. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 This Internet-Draft will expire on May 4, 2017. 34 Copyright Notice 36 Copyright (c) 2016 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (http://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 52 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 53 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 54 3. G.709 Optical Transport Network . . . . . . . . . . . . . . . 3 55 3.1. OTN ODUCn layer network . . . . . . . . . . . . . . . . . 3 56 3.2. Time Slot Granularity . . . . . . . . . . . . . . . . . . 4 57 3.3. Structure of MSI Information . . . . . . . . . . . . . . 5 58 3.4. OTUCn sub rates (OTUCn-M) . . . . . . . . . . . . . . . . 6 59 4. Connection Management of ODUCn . . . . . . . . . . . . . . . 6 60 5. GMPLS Implications . . . . . . . . . . . . . . . . . . . . . 6 61 5.1. Implications for GMPLS Signalling . . . . . . . . . . . . 6 62 5.2. Implications for GMPLS Routing . . . . . . . . . . . . . 7 63 5.3. Implications for Control-Plane Backward Compatibility . . 7 64 6. Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . 7 65 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 66 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 67 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 68 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 69 9.2. Informative References . . . . . . . . . . . . . . . . . 8 70 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 72 1. Introduction 74 Currently, Optical Transport Networks (OTNs) is widely used in the 75 transport network. Some operators already use control-plane 76 capabilities based on GMPLS to control optical transport network to 77 improve the network management efficiency. 79 The GMPLS signalling extensions defined in [RFC4328] provide the 80 mechanisms for basic GMPLS control of OTN based on the 2001 revision 81 of the G.709 specification. The 2012 revision of the G.709 82 specification, [G709-2012], introduce some new features, and the 83 GMPLS control of OTN based on the 2012 revision of the G.709 84 specification is covered in [RFC7062], [RFC7096], [RFC7138] and 85 [RFC7139]. The 2016 revision of the G.709 specification includes 86 some new features, such as OTUCn, ODUCn and OPUCn. The OTUCn 87 contains an optical data unit (ODUCn) and the ODUCn contains an 88 optical payload unit (OPUCn). OTUCn, ODUCn and OPUCn are presented 89 in an interface independent manner, by means of n OTUC, ODUC and OPUC 90 instances that are marked #1 to #n through inverse multiplexing. 92 This document reviews relevant aspects of OTN technology evolution 93 that affect the GMPLS control-plane protocols, examines why and how 94 to update the mechanisms described in former G.709 related documents 95 and describes the framework and solution for GMPLS control of ODUCn 96 network. 98 For the purposes of the control plane, the OTN can be considered to 99 be comprised of ODU and wavelength (Optical Channel (OCh)/ Optical 100 Tributary Signal (OTSi)) layers. This document focuses on the 101 control of the ODU layer, with control of the wavelength layer 102 considered out of the scope. 104 1.1. Requirements Language 106 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 107 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 108 document are to be interpreted as described in RFC 2119 [RFC2119]. 110 2. Terminology 112 OPUCn Optical Payload Unit-Cn 114 ODUCn Optical Data Unit-Cn 116 OTUCn completely standardized Optical Transport Unit-Cn 118 OTUCn-M Optical Transport Unit-Cn with n OxUC overhead instances and 119 M 5G tributary slots 121 OTUCn completely standardized Optical Transport Unit-Cn 123 3. G.709 Optical Transport Network 125 This section provides an informative overview of the aspects of the 126 OTN impacting control-plane protocols. This overview is based on the 127 ITU-T Recommendations that contain the normative definition of the 128 OTN. Technical details regarding OTN architecture and interfaces are 129 provided in the relevant ITU-T Recommendations. 131 3.1. OTN ODUCn layer network 133 Figure 1 shows a simplified signal hierarchy of OTN ODUCn, which 134 illustrates the layers that are related to control plane. 136 client signal (OTN clients) 137 | 138 ODUCn 139 | 140 OTUCn 142 Figure 1: OTN ODUCn Signal Hierarchy 144 ODUCn can no be used to support non-OTN client signal. OTN client 145 signals (e.g. ODU0, ODU1, ODU2, ODU2e, ODU3, ODU4, ODUflex) are 146 mapped into an ODUCn container, ODUCn container is then multiplexed 147 into OTUCn. The approximate bit rates of these signals are defined 148 in [G709-2016] and are reproduced in Figure 2. 150 +-------------------+------------------------------------+ 151 | ODU Type | ODU nominal bit rate | 152 +-------------------+------------------------------------+ 153 | ODU0 | 1,244,160 Kbps | 154 | ODU1 | 239/238 x 2,488,320 Kbps | 155 | ODU2 | 239/237 x 9,953,280 Kbps | 156 | ODU3 | 239/236 x 39,813,120 Kbps | 157 | ODU4 | 239/227 x 99,532,800 Kbps | 158 | ODUCn | n x 239/226 x 99 532 800 kbit/s | 159 | ODU2e | 239/237 x 10,312,500 Kbps | 160 | | | 161 | ODUflex for | | 162 |Constant Bit Rate | 239/238 x client signal bit rate | 163 | Client signals | | 164 | | | 165 |ODUflex for Generic| | 166 | Framing Procedure | Configured bit rate | 167 | - Framed (GFP-F) | | 168 | Mapped client | | 169 | signal | | 170 | | | 171 | ODUflex for IMP |s x 239/238 x 5 156 250 kbit/s | 172 | mapped client |s = 2, 8, n x 5 with n >= 1 | 173 | signals | | 174 | | | 175 | ODUflex for FlexE |103 125 000 x 240/238 x n/20 kbit/s | 176 | aware client |(n = n1 + n2 + .. + np) | 177 | signals | | 178 +-------------------+------------------------------------+ 180 Figure 2: ODU Types and Bit Rates 182 3.2. Time Slot Granularity 184 The initial versions of G.709 referenced by [RFC4328] only provided a 185 single TS granularity, nominally 2.5 Gbps. [G709-2012] added an 186 additional TS granularity, nominally 1.25 Gbps. [G709-2012] added 187 another 5 Gbps TS granularity specially for ODUCn. The number of 188 tributary slots (TS) defined in [G709-2016] for each ODU are 189 reproduced in Figure 3. 191 +------------+-------------------------------------+ 192 | | Nominal TS capacity | 193 | ODU Server +-------------------------------------+ 194 | | 1.25 Gbit/s | 2.5 Gbit/s | 5 Gbit/s | 195 +------------+-------------+------------+----------+ 196 | ODU0 | 1 | N/A | N/A | 197 +------------+-------------+------------+----------+ 198 | ODU1 | 2 | N/A | N/A | 199 +------------+-------------+------------+----------+ 200 | ODU2 | 8 | 4 | N/A | 201 +------------+-------------+------------+----------+ 202 | ODU3 | 32 | 16 | N/A | 203 +------------+-------------+------------+----------+ 204 | ODU4 | 80 | N/A | N/A | 205 +------------+-------------+------------+----------+ 206 | ODUCn | N/A | N/A | 20*n | 207 +------------+-------------+------------+----------+ 209 Figure 3: Number of tributary slots (TS) 211 3.3. Structure of MSI Information 213 When multiplexing an OTN client signal into ODUCn, [G.709-2016] 214 specifies the information that has to be transported in-band in order 215 to allow for correct demultiplexing. This information, known as MSI, 216 is transported in the OPUCn overhead and is local to each link. 218 The MSI information is organized as a set of entries, with n entries 219 for each OPUC TS. The MSI indicates the ODTU content of each 220 tributary slot of an OPU. Two bytes are used for each tributary 221 slot. The information carried by each entry is: 223 - TS availability bit 1 indicates if the tributary slot is available 224 or unavailable. 226 - The TS occupation bit 9 indicates if the tributary slot is 227 allocated or unallocated. 229 - Payload Type: the type of the transported payload. 231 - TPN: the port number of the OTN client signal transported by the 232 ODUCn. The TPN is the same for all the TSs assigned to the transport 233 of the same OTN client signal. 235 3.4. OTUCn sub rates (OTUCn-M) 237 An OTUCn with a bit rate that is not an integer multiple of 100 Gbit/ 238 s is described as an OTUCn M, it carries n instances of OTUC 239 overhead, ODUC overhead and OPUC overhead together with M 5Gbit/s 240 OPUCn TS. An ODUCn M and OPUCn M are not defined. When an OTUCn M 241 is used to carry an ODUCn (20n-M) TS are marked as unavailable, in 242 the OPUCn multiplex structure identifier (MSI), since they cannot be 243 used to carry a client. 245 4. Connection Management of ODUCn 247 ODUCn based connection management is concerned with controlling the 248 connectivity of ODUCn paths. As described in [G.872], The ODUk 249 subnetwork does not support an ODUCn, which means intermediate ODUCn 250 points do not support the switching of ODUCn time slot, intermediate 251 ODUCn point only functions as a forwarding point. Once an ODUCn path 252 is used to transport client signal, the TS occupied will not changed 253 across the ODUCn network. 255 5. GMPLS Implications 257 The purpose of this section is to provide a set of requirements to be 258 evaluated for extensions of the current GMPLS protocol suite to 259 encompass OTN enhancements and connection management. 261 5.1. Implications for GMPLS Signalling 263 As described in Section 3, [G709-2016] introduced some new features, 264 such as OTUCn, ODUCn and OPUCn. The mechanisms defined in [RFC4328] 265 and [RFC7139] do not support such new OTN features, and protocol 266 extensions will be necessary to allow them to be controlled by a 267 GMPLS control plane. The following signaLling aspects should be 268 considered: 270 - Support for specifying new signal types and related traffic 271 information. The traffic parameters should be extended in a 272 signalling message to support the new ODUCn 274 - Support for LSP setup using different TS granularity 276 - Support for LSP setup of new ODUCn containers with related mapping 277 and multiplexing capabilities 279 - Support for TPN allocation and negotiation 281 - Support for LSP setup of OTUCn sub rates (OTUCn-M) path 282 Note: ODU Virtual Concatenation (VCAT) and Link Capacity Adjustment 283 Scheme (LCAS) is not supported in ODUCn network. 285 5.2. Implications for GMPLS Routing 287 The path computation process needs to select a suitable route for an 288 ODUCn connection request. In order to perform the path computation, 289 it needs to evaluate the available bandwidth on one or more candidate 290 links. The routing protocol should be extended to convey sufficient 291 information to represent ODU Traffic Engineering (TE) topology. 292 Following requirements should be considered: 294 - Support for Tributary Slot Granularity advertisement 296 - Support for carrying the link multiplexing capability 298 The routing protocol should be able to indicate which link supports 299 the ODUCn forwarding. 301 - Support for advertisement of OTUCn sub rates support information 303 5.3. Implications for Control-Plane Backward Compatibility 305 TBD 307 6. Solutions 309 TBD 311 7. Security Considerations 313 TBD 315 8. IANA Considerations 317 TBD 319 9. References 321 9.1. Normative References 323 [G.709] Maarten, Vissers., "Interfaces for Optical Transport 324 Network", 2016. 326 [G.872] Malcolm, Betts., "Architecture of optical transport 327 networks (OTN)", 2016. 329 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 330 Requirement Levels", BCP 14, RFC 2119, 331 DOI 10.17487/RFC2119, March 1997, 332 . 334 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 335 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 336 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 337 . 339 [RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label 340 Switching (GMPLS) Signaling Functional Description", 341 RFC 3471, DOI 10.17487/RFC3471, January 2003, 342 . 344 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 345 Switching (GMPLS) Signaling Resource ReserVation Protocol- 346 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 347 DOI 10.17487/RFC3473, January 2003, 348 . 350 [RFC3603] Marshall, W., Ed. and F. Andreasen, Ed., "Private Session 351 Initiation Protocol (SIP) Proxy-to-Proxy Extensions for 352 Supporting the PacketCable Distributed Call Signaling 353 Architecture", RFC 3603, DOI 10.17487/RFC3603, October 354 2003, . 356 [RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions 357 in Support of Generalized Multi-Protocol Label Switching 358 (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, 359 . 361 [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in 362 Support of Generalized Multi-Protocol Label Switching 363 (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, 364 . 366 [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, 367 DOI 10.17487/RFC4204, October 2005, 368 . 370 9.2. Informative References 372 [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label 373 Switching (GMPLS) Architecture", RFC 3945, 374 DOI 10.17487/RFC3945, October 2004, 375 . 377 Authors' Addresses 379 Qilei Wang (editor) 380 ZTE 381 Nanjing 382 CN 384 Email: wang.qilei@zte.com.cn 386 Yuanbin Zhang 387 ZTE 388 Beijing 389 CN 391 Email: zhang.yuanbin@zte.com.cn