idnits 2.17.1 draft-ietf-teas-pce-native-ip-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 : ---------------------------------------------------------------------------- ** There are 7 instances of too long lines in the document, the longest one being 5 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 13, 2018) is 2263 days in the past. Is this intentional? -- Found something which looks like a code comment -- if you have code sections in the document, please surround them with '' and '' lines. Checking references for intended status: Experimental ---------------------------------------------------------------------------- No issues found here. Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 TEAS Working Group A.Wang 2 Internet Draft China Telecom 3 Quintin Zhao 4 Boris Khasanov 5 HuaiMo Chen 6 Huawei Technologies 7 Penghui Mi 8 Tencent Company 10 Intended status: Experimental Track February 13, 2018 11 Expires: August 12, 2018 13 PCE in Native IP Network 14 draft-ietf-teas-pce-native-ip-00.txt 16 Status of this Memo 18 This Internet-Draft is submitted in full conformance with the 19 provisions of BCP 78 and BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF). Note that other groups may also distribute 23 working documents as Internet-Drafts. The list of current Internet- 24 Drafts is at https://datatracker.ietf.org/drafts/current/. 26 Internet-Drafts are draft documents valid for a maximum of six 27 months and may be updated, replaced, or obsoleted by other documents 28 at any time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 This Internet-Draft will expire on August 12, 2018. 33 Copyright Notice 35 Copyright (c) 2018 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents 40 (https://trustee.ietf.org/license-info) in effect on the date of 41 publication of this document. Please review these documents 42 carefully, as they describe your rights and restrictions with 43 respect to this document. Code Components extracted from this 44 document must include Simplified BSD License text as described in 45 Section 4.e of the Trust Legal Provisions and are provided 46 without warranty as described in the Simplified BSD License. 48 Abstract 50 This document defines the framework for CCDR traffic engineering 51 within Native IP network, using Dual/Multi-BGP session strategy and 52 PCE-based central control architecture. 54 The proposed central mode control framework conforms to the concept 55 that defined in RFC " An Architecture for Use of PCE and the PCE 56 Communication Protocol (PCEP) in a Network with Central Control". 58 The scenario and simulation results of CCDR traffic engineering is 59 described in draft "CCDR Scenario, Simulation and Suggestion". 61 Table of Contents 63 1. Introduction ................................................. 2 64 2. Dual-BGP framework for simple topology. ...................... 3 65 3. Dual-BGP in large Scale Topology ............................. 4 66 4. Multi-BGP for Extended Traffic Differentiation ............... 5 67 5. CCDR based framework for Multi-BGP strategy deployment........ 6 68 6. PCEP extension for key parameters delivery. .................. 7 69 7. CCDR Deployment Consideration ................................ 7 70 8. Security Considerations....................................... 8 71 9. IANA Considerations .......................................... 8 72 10. Conclusions ................................................. 8 73 11. References .................................................. 9 74 11.1. Normative References.................................... 9 75 11.2. Informative References.................................. 9 76 12. Acknowledgments ............................................ 10 78 1. Introduction 80 Draft [I-D.draft-wang-teas-ccdr] describes the scenario and simulation 81 results for the CCDR traffic engineering. In summary, the requirements for 82 CCDR traffic engineering in Native IP network are the followings. 83 1) No complex MPLS signaling procedure. 84 2) End to End traffic assurance, determined QoS behavior. 85 3) Identical deployment method for intra- and inter- domain. 86 4) No influence to existing router forward behavior. 87 5) Can utilize the power of centrally control(PCE) and 88 flexibility/robustness of distributed control protocol. 89 6) Coping with the differentiation requirements for large amount 90 traffic and prefixes. 91 7) Flexible deployment and automation control. 93 This document defines the framework for CCDR traffic engineering 94 within Native IP network, using Dual/Multi-BGP session strategy and 95 CCDR architecture, to meet the above requirements in dynamical and 96 central control mode. Future PCEP protocol extensions to transfer the 97 key parameters between PCE and the underlying network devices(PCC) 98 are provided in draft [draft-wang-pcep-extension-native-IP] 100 2. Dual-BGP framework for simple topology. 102 Dual-BGP framework for simple topology is illustrated in Fig.1, which 103 is comprised by SW1, SW2, R1, R2. There are multiple physical links 104 between R1 and R2. Traffic between IP11 and IP21 is normal traffic, 105 traffic between IP12 and IP22 is priority traffic that should be 106 treated differently. 108 Only Native IGP/BGP protocol is deployed between R1 and R2. The traffic 109 between each address pair may change timely and the corresponding 110 source/destination addresses of the traffic may also change dynamically. 112 The key idea of the Dual-BGP framework for this simple topology is 113 the following: 114 1) Build two BGP sessions between R1 and R2, via the different loopback 115 address lo0, lo1 on these routers. 116 2) Send different prefixes via the two BGP sessions. (For example, 117 IP11/IP21 via the BGP pair 1 and IP12/IP22 via the BGP pair 2). 118 3) Set the explicit peer route on R1 and R2 respectively for BGP next 119 hop of lo0, lo1 to different physical link address between R1 and 120 R2. 122 So, the traffic between the IP11 and IP21, and the traffic between 123 IP12 and IP22 will go through different physical links between R1 and 124 R2, each type of traffic occupy the different dedicated physical 125 links. 127 If there is more traffic between IP12 and IP22 that needs to be 128 assured , one can add more physical links on R1 and R2 to reach the 129 loopback address lo1(also the next hop for BGP Peer pair2). In this 130 cases the prefixes that advertised by two BGP peer need not be 131 changed. 133 If, for example, there is traffic from another address pair that 134 needs to be assured (for example IP13/IP23), but the total volume of 135 assured traffic does not exceed the capacity of the previous 136 appointed physical links, then one need only to advertise the newly 137 added source/destination prefixes via the BGP peer pair2, then the 138 traffic between IP13/IP23 will go through the assigned dedicated 139 physical links as the traffic between IP12/IP22. 141 Such decouple philosophy gives the network operator more flexible 142 control ability on the network traffic, get the determined QoS 143 assurance effect to meet the application's requirement. No complex 144 MPLS signal procedures is introduced, the router need only support 145 native IP protocol. 147 | BGP Peer Pair2 | 148 +------------------+ 149 |lo1 lo1 | 150 | | 151 | BGP Peer Pair1 | 152 +------------------+ 153 IP12 |lo0 lo0 | IP22 154 IP11 | | IP21 155 SW1-------R1-----------------R2-------SW2 156 Links Group 158 Fig.1 Design Philosophy for Dual-BGP Framework 160 3. Dual-BGP in large Scale Topology 162 When the assured traffic spans across one large scale network, as 163 that illustrated in Fig.2,the dual BGP sessions cannot be 164 established hop by hop especially for the iBGP within one AS. For 165 such scenario, we should consider to use the Route Reflector (RR) to 166 achieve the similar Dual-BGP effect, select one router which performs 167 the role of RR (for example R3 in Fig.2), every other edge router 168 will establish two BGP peer sessions with the RR, using their 169 different loopback addresses respectively. The other two steps for 170 traffic differentiation are same as one described in the Dual-BGP 171 simple topology usage case. 173 For the example shown in Fig.2, if we select the R1-R2-R4-R7 as the 174 dedicated path, then we should set the explicit peer routes on these 175 routers respectively, pointing to the BGP next hop (loopback 176 addresses of R1 and R7, which are used to send the prefix of the 177 assured traffic) to the actual address of the physical link 179 +------------R3--------------+ 180 | | 182 SW1-------R1-------R5---------R6-------R7--------SW2 183 | | | | 184 +-------R2---------R4--------+ 186 Fig.2 Dual-BGP Framework for large scale network 188 4. Multi-BGP for Extended Traffic Differentiation 190 In general situation, several additional traffic differentiation 191 criteria exist, including: 192 o Traffic that requires low latency links and is not sensitive to 193 packet loss 194 o Traffic that requires low packet loss but can endure higher latency 195 o Traffic that requires lowest jitter path 196 o Traffic that requires high bandwidth links 198 These different traffic requirements can be summarized in the 199 following table: 201 +----------+-------------+---------------+-----------------+ 202 | Flow No. | Latency | Packet Loss | Jitter | 203 +----------+-------------+---------------+-----------------+ 204 | 1 | Low | Normal | Don't care | 205 +----------+-------------+---------------+-----------------+ 206 | 2 | Normal | Low | Dont't care | 207 +----------+-------------+---------------+-----------------+ 208 | 3 | Normal | Normal | Low | 209 +----------+-------------+---------------+-----------------+ 210 Table 1. Traffic Requirement Criteria 212 For Flow No.1, we can select the shortest distance path to carry the 213 traffic; for Flow No.2, we can select the idle links to form its end 214 to end path; for Flow No.3, we can let all the traffic pass one 215 single path, no ECMP distribution on the parallel links is required. 217 It is difficult and almost impossible to provide an end-to-end (E2E) 218 path with latency, latency variation, packet loss, and bandwidth 219 utilization constraints to meet the above requirements in large scale 220 IP-based network via the traditional distributed routing protocol, 221 but these requirements can be solved using the CCDR architecture 222 since the PCE has the overall network view, can collect real network 223 topology and network performance information about the underlying 224 network, select the appropriate path to meet the various network 225 performance requirements of different traffic type. 227 5. CCDR based framework for Multi-BGP strategy deployment. 229 With the advent of SDN concepts towards pure IP networks, it is 230 possible now to accomplish the central and dynamic control of network 231 traffic according to the application's various requirements. 233 The procedure to implement the dynamic deployment of Multi-BGP 234 strategy is the following: 235 1) PCE gets topology and link utilization information from the 236 underlying network, calculate the appropriate link path upon 237 application's requirements. 238 2) PCE sends the key parameters to edge/RR routers(R1, R7 and R3 in 239 Fig.3) to build multi-BGP peer relations and advertise different 240 prefixes via them. 241 3) PCE sends the route information to the routers (R1,R2,R4,R7 in 242 Fig.3) on forwarding path via PCEP, to build the path to the BGP 243 next-hop of the advertised prefixes. 244 4) If the assured traffic prefixes were changed but the total volume 245 of assured traffic does not exceed the physical capacity of the 246 previous end-to-end path, then PCE needs only change the related 247 information on edge routers (R1,R7 in Fig.3). 248 5) If volume of the assured traffic exceeds the capacity of previous 249 calculated path, PCE must recalculate the appropriate path to 250 accommodate the exceeding traffic via some new end-to-end physical 251 link. After that PCE needs to update on-path routers to build such 252 path hop by hop. 254 +----+ 255 ***********+PCE +************* 256 * +--*-+ * 257 * / * \ * 258 * * * 259 PCEP* *BGP-LS/SNMP *PCEP 260 * * * 261 * * \ * / 262 \ * / * \ */ 263 \*/-----------R3--------------* 264 | | 265 | | 266 SW1-------R1-------R5---------R6-------R7--------SW2 267 | | | | 268 | | | | 269 +-------R2---------R4--------+ 271 Fig.3 PCE based framework for Multi-BGP deployment 273 6. PCEP extension for key parameters delivery. 275 The PCEP protocol needs to be extended to transfer the following key 276 parameters: 277 1) BGP peer address and advertised prefixes. 278 2) Explicit route information to BGP next hop of advertised prefixes. 280 Once the router receives such information, it should establish the 281 BGP session with the peer appointed in the PCEP message, advertise 282 the prefixes that contained in the corresponding PCEP message, and 283 build the end to end dedicated path hop by hop. Details of 284 communications between PCEP and BGP subsystems in router's control 285 plane are out of scope of this draft and will be described in 286 separate draft.[draft-wang-pce-extension for native IP] 288 The reason why we selected PCEP as the southbound protocol instead of 289 OpenFlow, is that PCEP is suitable for the changes in control plane 290 of the network devices, there OpenFlow dramatically changes the 291 forwarding plane. We also think that the level of centralization that 292 requires by OpenFlow is hardly achievable in many today's SP networks 293 so hybrid BGP+PCEP approach looks much more interesting. 295 7. CCDR Deployment Consideration 297 CCDR framework requires the parallel work of 2 subsystems in router's 298 control plane: PCE (PCEP) and BGP as well as coordination between 299 them, so it might require additional planning work before deployment. 301 8.1 Scalability 303 In CCDR framework, PCE needs only to influence the edge routers for 304 the prefixes differentiation via the multi-BGP deployment. The route 305 information for these prefixes within the on-path routers were 306 distributed via the traditional BGP protocol. Unlike the solution 307 from BGP Flowspec, the on-path router need only keep the specific 308 policy routes to the BGP next-hop of the differentiate prefixes, not 309 the specific routes to the prefixes themselves. This can lessen the 310 burden from the table size of policy based routes for the on-path 311 routers, and has more scalability when comparing with the solution 312 from BGP flowspec or Openflow. 314 8.2 High Availability 316 CCDR framework is based on the traditional distributed IP protocol. 317 If the PCE failed, the forwarding plane will not be impacted, as the 318 BGP session between all devices will not flap, and the forwarding 319 table will remain the same. If one node on the optimal path is failed, 320 the assurance traffic will fall over to the best-effort forwarding 321 path. One can even design several assurance paths to load balance/hot 322 standby the assurance traffic to meet the path failure situation, as 323 done in MPLS FRR. 324 From PCE/SDN-controller HA side we will rely on existing HA solutions 325 of SDN controllers such as clustering. 327 8.3 Incremental deployment 329 Not every router within the network support will support the PCEP 330 extension that defined in [draft-wang-pce-extension-native-IP] 331 simultaneously. For such situations, router on the edge of sub domain 332 can be upgraded first, and then the traffic can be assured between 333 different sub domains. Within each sub domain, the traffic will be 334 forwarded along the best-effort path. Service provider can 335 selectively upgrade the routers on each sub-domain in sequence. 337 8. Security Considerations 339 TBD 341 9. IANA Considerations 343 TBD 345 10. Conclusions 347 TBD 349 11. References 351 11.1. Normative References 353 [RFC5440]Vasseur, JP., Ed., and JL. Le Roux, Ed., "Path 355 Computation Element (PCE) Communication Protocol 357 (PCEP)", RFC 5440, March 2009, 359 . 361 [RFC8283] A.Farrel, Q.Zhao et al.," An Architecture for Use of PCE 362 and the PCE Communication Protocol (PCEP) in a Network with Central 363 Control", [RFC8283], December 2017 365 11.2. Informative References 367 [I-D.draft-wang-teas-ccdr] 369 A.Wang, X.Huang et al. "CCDR Scenario, Simulation and Suggestion" 371 https://datatracker.ietf.org/doc/draft-wang-teas-ccdr/ 373 [I-D. draft-ietf-teas-pcecc-use-cases] 375 Quintin Zhao, Robin Li, Boris Khasanov et al. "The Use Cases for 376 Using PCE as the Central Controller(PCECC) of LSPs 378 https://tools.ietf.org/html/draft-ietf-teas-pcecc-use-cases-00 380 March,2017 382 [draft-wang-pcep-extension for native IP] 383 Aijun Wang, Boris Khasanov et al. "PCEP Extension for Native IP 384 Network" https://datatracker.ietf.org/doc/draft-wang-pce-extension- 385 native-ip/ 387 12. Acknowledgments 389 The authors would like to thank George Swallow, Xia Chen, Jeff 390 Tantsura,Scharf Michael,Daniele Ceccarelli and Dhruv Dhody for their 391 valuable comments and suggestions. 393 The authors would also like to thank Lou Berger, Adrian Farrel, 394 Vishnu Pavan Beeram, Deborah Brungard and King Daniel for their 395 suggestions to put forward this draft. 397 Authors' Addresses 399 Aijun Wang 400 China Telecom 401 Beiqijia Town, Changping District 402 Beijing,China 404 Email: wangaj.bri@chinatelecom.cn 405 Quintin Zhao 406 Huawei Technologies 407 125 Nagog Technology Park 408 Acton, MA 01719 409 USA 411 EMail: quintin.zhao@huawei.com 413 Boris Khasanov 414 Huawei Technologies 415 Moskovskiy Prospekt 97A 416 St.Petersburg 196084 417 Russia 419 EMail: khasanov.boris@huawei.com 421 Huaimo Chen 422 Huawei Technologies 423 Boston, MA, 424 USA 426 EMail: huaimo.chen@huawei.com 428 Penghui Mi 429 Tencent 430 Tencent Building, Kejizhongyi Avenue, 431 Hi-techPark, Nanshan District,Shenzhen 518057, P.R.China 433 Email kevinmi@tencent.com 435 Raghavendra Mallya 436 Juniper Networks 437 1133 Innovation Way 438 Sunnyvale, California 94089 USA 440 Email: rmallya@juniper.net 442 Shaofu Peng 443 ZTE Corporation 444 No.68 Zijinghua Road,Yuhuatai District 445 Nanjing 210012 446 China 448 Email: peng.shaofu@zte.com.cn