基于PCE的下一代光网络路由技术研究
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摘要
随着下一代光网络规模的不断扩大,网络拓扑越来越复杂,路由计算也越来越复杂,原有的路由技术已不能满足复杂的路由计算要求。为了解决这个问题,IETF (互联网工程任务组) PCE(路径计算单元)工作组提出了专门用于路径计算的模块——路径计算单元。通过在网络中部署独立的路径计算单元可以处理ASON(自动交换光网络)网络中大量基于约束的路径计算请求,尤其是在多域光网络的路径计算中,PCE比原有的路由技术有明显的优势。
正是基于这样的下一代光网络路由技术发展的背景下,PCE技术也发展的逐步成熟和规范化。目前IETF PCE工作组已完成了相关的一系列标准和草案。本论文的工作紧密围绕下一代光网络中的路由技术,尤其是PCE技术展开,主要分为以下几部分:
(1)从下一代光网络路由技术的发展过程出发,对路径计算单元PCE模块进行了研究,包括PCE的体系架构,计算模型,PCE发现机制和策略等相关内容进行了系统和全面的研究。
(2)对PCEP (PCE通信协议)及其有限状态图进行了分析,并提出了PCE路径请求模块和路径回复模块实施的方案,此外,对PCEP在光网络中的扩展进行了研究。
(3)对PCE在下一代光网络中路由与波长分配模型中的应用进行研究,通过对多域光网络中普通路径的计算算法和基于PCE的多域光网络的路径计算算法进行比较分析,说明了PCE结合了各个域间的网络资源信息,掌握全网拓扑结构,可计算出最优路径,从而提高了网络利用率。
With the scale development of Automatically Switched Optical Network (ASON), the network topology becomes more and more complicated, and so does the routing computation, consequently, the original routing technology cannot satisfy the requirements of complicated path computation. To resolve the problem, PCE architecture was proposed by the IETF PCE Work Group. The large number of constraint-based path computation problem can be resolved by deploying independent PCE in ASON, which has more significant advantage than the original routing technology especially in the path calculation of multi-domain optical network.
Based on next generation optical network technology development in the context of routing, PCE technology development, and gradually mature and standardized. Currently, IETF PCE Working Group had completed a series of related standards and draft. Routing technology especially PCE technology of the next generation optical network was researched in this paper and the main contents were as follows:
(1) According to the developing process of the next generation optical network, PCE module including PCE architecture, computing model, PCE discovery mechanism and strategies and so on were studied systematically and comprehensively.
(2) PCE computation protocols(PCEP) and the finite state diagrams were both analyzed, and the implementing schemes of PCE path request and reply modules were proposed, besides, the PCEP extensions in optical networks was studied.
(3) Study on PCE in the model of routing and wavelength assignment in the next generation optical network. By contrast with the computing algorithm of the common path of multi-domain optical networks and computing method based on PCE, it was shown that PCE combined the information of various inter-domain network resources and mastered the whole network topology, so that it can calculate the optimal path, thus improving network utilization.
正是基于这样的下一代光网络路由技术发展的背景下,PCE技术也发展的逐步成熟和规范化。目前IETF PCE工作组已完成了相关的一系列标准和草案。本论文的工作紧密围绕下一代光网络中的路由技术,尤其是PCE技术展开,主要分为以下几部分:
(1)从下一代光网络路由技术的发展过程出发,对路径计算单元PCE模块进行了研究,包括PCE的体系架构,计算模型,PCE发现机制和策略等相关内容进行了系统和全面的研究。
(2)对PCEP (PCE通信协议)及其有限状态图进行了分析,并提出了PCE路径请求模块和路径回复模块实施的方案,此外,对PCEP在光网络中的扩展进行了研究。
(3)对PCE在下一代光网络中路由与波长分配模型中的应用进行研究,通过对多域光网络中普通路径的计算算法和基于PCE的多域光网络的路径计算算法进行比较分析,说明了PCE结合了各个域间的网络资源信息,掌握全网拓扑结构,可计算出最优路径,从而提高了网络利用率。
With the scale development of Automatically Switched Optical Network (ASON), the network topology becomes more and more complicated, and so does the routing computation, consequently, the original routing technology cannot satisfy the requirements of complicated path computation. To resolve the problem, PCE architecture was proposed by the IETF PCE Work Group. The large number of constraint-based path computation problem can be resolved by deploying independent PCE in ASON, which has more significant advantage than the original routing technology especially in the path calculation of multi-domain optical network.
Based on next generation optical network technology development in the context of routing, PCE technology development, and gradually mature and standardized. Currently, IETF PCE Working Group had completed a series of related standards and draft. Routing technology especially PCE technology of the next generation optical network was researched in this paper and the main contents were as follows:
(1) According to the developing process of the next generation optical network, PCE module including PCE architecture, computing model, PCE discovery mechanism and strategies and so on were studied systematically and comprehensively.
(2) PCE computation protocols(PCEP) and the finite state diagrams were both analyzed, and the implementing schemes of PCE path request and reply modules were proposed, besides, the PCEP extensions in optical networks was studied.
(3) Study on PCE in the model of routing and wavelength assignment in the next generation optical network. By contrast with the computing algorithm of the common path of multi-domain optical networks and computing method based on PCE, it was shown that PCE combined the information of various inter-domain network resources and mastered the whole network topology, so that it can calculate the optimal path, thus improving network utilization.
引文
[1]荆瑞泉.ASON路由技术的现状与发展[J].电信科学, 2005, (11): 2~3
[2] D. King, Y. Lee, Huiying Xu, and A. Farrel. Path Computation Architectures Overview in Multidomain Optical Networks Based on ITU-T ASON and IETF PCE [C]. NOMS Workshops 2008. Salvador, Brazil. IEEE Volume , Issue , 7-11 April 2008 Page(s): 219~226
[3] ITU-T G.7715.2: The Applicability of PCE in an ASON environment [S]. 2006
[4]易小波,孙秀清,唐元春等.基于路径计算单元的MPLS/GMPLS网络结构[J].电信科学,2008, (2): 41~47
[5]荆瑞泉,杨玉森.自动交换光网络路由技术[J].现代通信科学技术, 2003, (3): 10~14
[6]张杰,赵永利等.一种新型的基于PCE的多层多域GMPLS/ASON光网络体系结构[J].中国通信,2009, (7): 64~71
[7] ITU-T.G 8080/Y 1304-2001, Architecture for the automatically switched optical network (ASON) [S]. Geneva 2001
[8]张杰,徐云斌,顾畹仪,等.自动交换光网络ASON [M].北京:人民邮电出版社, 2004.10~24
[9] Greg Bernstein, Bala Rajagopalan, Debanjan Saha著;黄蔚,郭丰,徐敏译,智能光网络-体系结构、协议和标准[M].北京:人民邮电出版社, 2007.249~262
[10] ITU-T.G 7715/Y 1706-2002, Architecture and requirements for routing in the automatically switched optical networks [S]. 2002
[11]毛宏宝,多域光网络的生存性机制研究[D].陕西:西安邮电学院, 2009
[12]张海懿.ASON技术、标准新进展[J].电信科学, 2008, (2): 1~7
[13] RFC4655: A Path Computation Element (PCE)-Based Architecture [S]. 2006
[14] RFC4657: Path Computation Element (PCE) Communication Protocol Generic Requirements [S]. 2006
[15] RFC4674: Requirements for Path Computation Element (PCE) Discovery [S]. 2006
[16] RFC4927: Path Computation Element Communication Protocol (PCECP) Specific Requirements for Inter-Area MPLS and GMPLS Traffic Engineering [S]. 2007
[17] RFC5088: OSPF Protocol Extensions for Path Computation Element (PCE) Discovery [S]. 2008
[18] RFC5089: IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery [S]. 2008
[19] RFC5376: Inter-AS Requirements for the Path Computation Element Communication Protocol (PCECP) [S]. 2008
[20] RFC5394: Policy-Enabled Path Computation Framework [S]. 2008
[21] RFC5440: Path Computation Element (PCE) Communication Protocol (PCEP) [S]. 2009
[22] RFC5455: Diff-Serv Aware Class Type Object for Path Computation Element Communication Protocol [S]. 2009
[23] RFC5441: A Backward-Recursive PCE-Based Computation (BRPC) Procedure to Compute Shortest Constrained Inter-Domain Traffic Engineering Label Switched Paths [S]. 2009
[24] RFC5521: Extensions to the Path Computation Element Communication Protocol (PCEP) for Route Exclusions [S]. 2009
[25] RFC5520: Preserving Topology Confidentiality in Inter-Domain Path Computation Using a Path-Key-Based Mechanism [S]. 2009
[26] RFC5541: Encoding of Objective Functions in the Path Computation Element Communication Protocol (PCEP) [S]. 2009
[27] RFC5557: Path Computation Element Communication Protocol (PCEP) Requirements and Protocol Extensions in Support of Global Concurrent Optimization [S]. 2009
[28] RFC5623: Framework for PCE-Based Inter-Layer MPLS and GMPLS Traffic Engineering [S]. 2009
[29] RFC5671: Applicability of the Path Computation Element (PCE) to Point-to-Multipoint (P2MP) MPLS and GMPLS Traffic Engineering (TE) [S]. 2009
[30] draft-ietf-pce-inter-layer-req-11.txt. PCC-PCE Communication and PCE Discovery Requirements for Inter-Layer Traffic Engineering [S]. Feb, 2010
[31] draft-ietf-pce-disc-mib-04.txt. Definitions of Managed Objects for Path Computation Element Discovery [S]. Oct, 2009
[32] draft-ietf-pce-tc-mib-05.txt. Definitions of Textual Conventions for Path Computation Element [S]. Oct, 2009
[33] draft-ietf-pce-manageability-requirements-08.txt. Inclusion of Manageability Sections in PCE Working Group Drafts [S]. Feb, 2010
[34] draft-ietf-pce-monitoring-08.txt. A set of monitoring tools for Path Computation Element based Architecture [S]. Jan, 2010
[35] draft-ietf-pce-inter-layer-ext-03.txt. Extensions to the Path Computation Element communication Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic Engineering [S]. Sep, 2009
[36] draft-ietf-pce-p2mp-req-05.txt. PCC-PCE Communication Requirements for Point to Multipoint Multiprotocol Label Switching Traffic Engineering (MPLS-TE) [S]. Jan, 2010
[37] draft-ietf-pce-pcep-p2mp-extensions-07.txt. Extensions to the Path Computation Element Communication Protocol (PCEP) for Point-to-Multipoint Traffic Engineering Label Switched Paths [S]. Feb, 2010
[38] draft-ietf-pce-pcep-svec-list-04.txt. The use of SVEC (Synchronization VECtor) list for Synchronized dependent path computations [S]. Feb, 2010
[39] draft-ietf-pce-pcep-mib-01.txt. PCE communication protocol(PCEP) Management InformationBase [S]. Mar, 2010
[40] draft-ietf-pce-vpn-req-01.txt. PCC-PCE Communication Requirements for VPNs [S]. Oct, 2009
[41] draft-ietf-pce-vendor-constraints-01.txt. Conveying Vendor-Specific Constraints in the Path Computation Element Protocol [S]. Mar, 2010
[42] draft-ietf-pce-wson-routing-wavelength-01.txt. PCEP Requirements for WSON Routing and Wavelength Assignment [S]. Mar, 2010
[43]张仁海.PCE发现协议的实现方法[P].中国专利: 1949744A, 2007-04-18
[44]李启铭,夏洪淼.域间PCE能力信息的获取方法、PCE及能力获取装置[P].中国专利: 101325542A, 2008-12-17
[45]陈国义.自治系统域间路径自动探测和计算的方法和装置[P].中国专利: 101155054A, 2008-04-02
[46]陈国义.协商PCC和PCE之间安全能力的方法及其网络系统[P].中国专利: 101335692A, 2008-12-31
[47]陈国义.一种在多域网络中请求计算路径的方法和设备[P].中国专利: 101552717A, 2009-10-07
[48]谢雪娟,多域光网络生存性技术[D].上海:上海交通大学, 2008
[49]谭志,纪越峰.多域分层路由技术[J].北京邮电大学学报, 2007, (1): 114~117
[50] ZANG H, JUE J P, MUKHERJEE B. A review of routing and wavelength assignment assignment approaches for wavelength-routed opticalWDM networks [J]. Optical Networks Magazine, 2000, (1) : 47~63
[51]董拥拥,多域光网络生存性和路由与波长分配研究[D].成都:电子科技大学, 2009
[52]项鹏,王荣.多域光网络中的动态RWA算法研究[J].2007, (1): 23~26
[53] Greg Bernstein and Young Lee. Extending GMPLS/PCE for use in Wavelength Switched Optical Networks [C]. OFC/NFOEC 2008. San Diego, CA. Feb. 2008 Page(s): 1~3
[54] A.Giorgetti et al. Routing and Wavelength Assignment in PCE-based Wavelength Switched Optical Networks [C]. Optical Communication, 2008. ECOC 2008. 34th European Conference. Brussels. Sept. 2008. Page(s): 1~2
[2] D. King, Y. Lee, Huiying Xu, and A. Farrel. Path Computation Architectures Overview in Multidomain Optical Networks Based on ITU-T ASON and IETF PCE [C]. NOMS Workshops 2008. Salvador, Brazil. IEEE Volume , Issue , 7-11 April 2008 Page(s): 219~226
[3] ITU-T G.7715.2: The Applicability of PCE in an ASON environment [S]. 2006
[4]易小波,孙秀清,唐元春等.基于路径计算单元的MPLS/GMPLS网络结构[J].电信科学,2008, (2): 41~47
[5]荆瑞泉,杨玉森.自动交换光网络路由技术[J].现代通信科学技术, 2003, (3): 10~14
[6]张杰,赵永利等.一种新型的基于PCE的多层多域GMPLS/ASON光网络体系结构[J].中国通信,2009, (7): 64~71
[7] ITU-T.G 8080/Y 1304-2001, Architecture for the automatically switched optical network (ASON) [S]. Geneva 2001
[8]张杰,徐云斌,顾畹仪,等.自动交换光网络ASON [M].北京:人民邮电出版社, 2004.10~24
[9] Greg Bernstein, Bala Rajagopalan, Debanjan Saha著;黄蔚,郭丰,徐敏译,智能光网络-体系结构、协议和标准[M].北京:人民邮电出版社, 2007.249~262
[10] ITU-T.G 7715/Y 1706-2002, Architecture and requirements for routing in the automatically switched optical networks [S]. 2002
[11]毛宏宝,多域光网络的生存性机制研究[D].陕西:西安邮电学院, 2009
[12]张海懿.ASON技术、标准新进展[J].电信科学, 2008, (2): 1~7
[13] RFC4655: A Path Computation Element (PCE)-Based Architecture [S]. 2006
[14] RFC4657: Path Computation Element (PCE) Communication Protocol Generic Requirements [S]. 2006
[15] RFC4674: Requirements for Path Computation Element (PCE) Discovery [S]. 2006
[16] RFC4927: Path Computation Element Communication Protocol (PCECP) Specific Requirements for Inter-Area MPLS and GMPLS Traffic Engineering [S]. 2007
[17] RFC5088: OSPF Protocol Extensions for Path Computation Element (PCE) Discovery [S]. 2008
[18] RFC5089: IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery [S]. 2008
[19] RFC5376: Inter-AS Requirements for the Path Computation Element Communication Protocol (PCECP) [S]. 2008
[20] RFC5394: Policy-Enabled Path Computation Framework [S]. 2008
[21] RFC5440: Path Computation Element (PCE) Communication Protocol (PCEP) [S]. 2009
[22] RFC5455: Diff-Serv Aware Class Type Object for Path Computation Element Communication Protocol [S]. 2009
[23] RFC5441: A Backward-Recursive PCE-Based Computation (BRPC) Procedure to Compute Shortest Constrained Inter-Domain Traffic Engineering Label Switched Paths [S]. 2009
[24] RFC5521: Extensions to the Path Computation Element Communication Protocol (PCEP) for Route Exclusions [S]. 2009
[25] RFC5520: Preserving Topology Confidentiality in Inter-Domain Path Computation Using a Path-Key-Based Mechanism [S]. 2009
[26] RFC5541: Encoding of Objective Functions in the Path Computation Element Communication Protocol (PCEP) [S]. 2009
[27] RFC5557: Path Computation Element Communication Protocol (PCEP) Requirements and Protocol Extensions in Support of Global Concurrent Optimization [S]. 2009
[28] RFC5623: Framework for PCE-Based Inter-Layer MPLS and GMPLS Traffic Engineering [S]. 2009
[29] RFC5671: Applicability of the Path Computation Element (PCE) to Point-to-Multipoint (P2MP) MPLS and GMPLS Traffic Engineering (TE) [S]. 2009
[30] draft-ietf-pce-inter-layer-req-11.txt. PCC-PCE Communication and PCE Discovery Requirements for Inter-Layer Traffic Engineering [S]. Feb, 2010
[31] draft-ietf-pce-disc-mib-04.txt. Definitions of Managed Objects for Path Computation Element Discovery [S]. Oct, 2009
[32] draft-ietf-pce-tc-mib-05.txt. Definitions of Textual Conventions for Path Computation Element [S]. Oct, 2009
[33] draft-ietf-pce-manageability-requirements-08.txt. Inclusion of Manageability Sections in PCE Working Group Drafts [S]. Feb, 2010
[34] draft-ietf-pce-monitoring-08.txt. A set of monitoring tools for Path Computation Element based Architecture [S]. Jan, 2010
[35] draft-ietf-pce-inter-layer-ext-03.txt. Extensions to the Path Computation Element communication Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic Engineering [S]. Sep, 2009
[36] draft-ietf-pce-p2mp-req-05.txt. PCC-PCE Communication Requirements for Point to Multipoint Multiprotocol Label Switching Traffic Engineering (MPLS-TE) [S]. Jan, 2010
[37] draft-ietf-pce-pcep-p2mp-extensions-07.txt. Extensions to the Path Computation Element Communication Protocol (PCEP) for Point-to-Multipoint Traffic Engineering Label Switched Paths [S]. Feb, 2010
[38] draft-ietf-pce-pcep-svec-list-04.txt. The use of SVEC (Synchronization VECtor) list for Synchronized dependent path computations [S]. Feb, 2010
[39] draft-ietf-pce-pcep-mib-01.txt. PCE communication protocol(PCEP) Management InformationBase [S]. Mar, 2010
[40] draft-ietf-pce-vpn-req-01.txt. PCC-PCE Communication Requirements for VPNs [S]. Oct, 2009
[41] draft-ietf-pce-vendor-constraints-01.txt. Conveying Vendor-Specific Constraints in the Path Computation Element Protocol [S]. Mar, 2010
[42] draft-ietf-pce-wson-routing-wavelength-01.txt. PCEP Requirements for WSON Routing and Wavelength Assignment [S]. Mar, 2010
[43]张仁海.PCE发现协议的实现方法[P].中国专利: 1949744A, 2007-04-18
[44]李启铭,夏洪淼.域间PCE能力信息的获取方法、PCE及能力获取装置[P].中国专利: 101325542A, 2008-12-17
[45]陈国义.自治系统域间路径自动探测和计算的方法和装置[P].中国专利: 101155054A, 2008-04-02
[46]陈国义.协商PCC和PCE之间安全能力的方法及其网络系统[P].中国专利: 101335692A, 2008-12-31
[47]陈国义.一种在多域网络中请求计算路径的方法和设备[P].中国专利: 101552717A, 2009-10-07
[48]谢雪娟,多域光网络生存性技术[D].上海:上海交通大学, 2008
[49]谭志,纪越峰.多域分层路由技术[J].北京邮电大学学报, 2007, (1): 114~117
[50] ZANG H, JUE J P, MUKHERJEE B. A review of routing and wavelength assignment assignment approaches for wavelength-routed opticalWDM networks [J]. Optical Networks Magazine, 2000, (1) : 47~63
[51]董拥拥,多域光网络生存性和路由与波长分配研究[D].成都:电子科技大学, 2009
[52]项鹏,王荣.多域光网络中的动态RWA算法研究[J].2007, (1): 23~26
[53] Greg Bernstein and Young Lee. Extending GMPLS/PCE for use in Wavelength Switched Optical Networks [C]. OFC/NFOEC 2008. San Diego, CA. Feb. 2008 Page(s): 1~3
[54] A.Giorgetti et al. Routing and Wavelength Assignment in PCE-based Wavelength Switched Optical Networks [C]. Optical Communication, 2008. ECOC 2008. 34th European Conference. Brussels. Sept. 2008. Page(s): 1~2