基于BFD的MPLS网络自愈恢复技术的研究与实现
摘要
随着Internet上业务流量的快速增长,网络应用的多元化发展,传统IP网络提供的尽力而为服务已经不能满足承载实时业务的需求。如何在故障发生时保证网络的连续性和服务质量(QoS),保持高水准的业务可用性,使传输网络能够自动检测失效并从故障中恢复成为当前迫切需要解决的问题。作为未来骨干网的核心技术,多协议标签交换(MPLS)技术通过标签交换机制,不仅可以提供比传统IP更有效的QoS保证和流量工程,也具有很强的网络生存能力。MPLS网络能够在节点或链路失效后,不需要人为的干预,就能自动的恢复受影响的业务,使整个网络保持健壮性和高效性。MPLS网络自愈恢复技术从故障检测技术和故障恢复技术两方面保证了MPLS网络的可用性和稳定性。
目前基于IP路由协议的恢复机制至少需要几秒到几分钟的时间,这将导致大量分组的丢失,造成严重的服务质量问题以及网络性能的下降。传统IP网络对实时应用(如语音)进行准确故障检测方面的能力有限,并且不具备秒以下的间歇性故障修复功能。伴随着VoIP应用的激增,实现快速网络故障检测和修复越发显得必要。MPLS网络自愈恢复技术能够在故障发生后,提供比IP层更快的反应时间,可以快速的检测到网络故障并从故障中恢复过来,维持网络的服务连续性。本文对MPLS网络故障检测技术进行深入的研究,采用双向转发检测BFD作为MPLS网络的故障检测技术,详细的设计和实现MPLS BFD技术,并将MPLS BFD技术应用于多核网络设备,使MPLS网络故障检测时间达到毫秒级,大大缩短了MPLS自愈恢复的故障检测时间。
MPLS网络检测到故障后,需要有一个较好的方案进行故障恢复。目前比较著名的两种MPLS故障方案有Makam方案,Haskin方案。Makam方案的优点是几乎没有分组的重排序问题,但却有分组丢失和保护时间较长的缺点。Haskin方案提供快速的路径切换,但是当工作路径上故障清除后,在流量从备份路径切换回原工作路径时,数据分组的重排序问题比较严重。因此如何设计出一种新的故障恢复方案,使得故障恢复速度快,报文不丢失,并且报文不发生重排序仍然是目前研究的热点。
本文在对现有故障恢复方案研究的基础上,提出了一种新的故障恢复方案——基于BFD的故障恢复方案,新方案利用局部恢复机制,建立备份路径,当故障发生后流量快速切换到备份路径,减少了由于流量切换而造成的报文丢失及报文延迟。针对报文失序的问题,本方案提出了一种新的解决方法——利用失序控制标签实现了对流量顺序地控制,避免了流量切换带来的报文失序。经过组网测试,新方案具有较快的故障恢复速度,对报文丢失,报文失序现象都有明显地改善效果。
The traditional IP network now fails to serve the need of bearer real-time service in an effective way with its best-effort service against the backdrop of ever-increasing Internet service traffic and gradually diversified network service. There is an urgent need to guarantee the network continuity and Quality-of-Service (QoS) against network fault in order to obtain ideal service availability to help the automatic detection of network failure and recovery from that failure. As the core technology for the future backbone network, Multi-Protocol Label Switching (MPLS), by means of label-swapping technique, is expected to offer the Quality-of-Service (QoS) and traffic engineering more effective and potential than ever before. The MPLS network automatically resumes the interrupted service and maintains the robustness and efficiency of the network as a whole even in the case of node failure or link failure. The self-recovery technology of MPLS network is used to protect the network feasibility and stability in terms of fault detection technique and fault recovery.
It takes at least several seconds or even a couple of minutes for the current recovery mechanism of the IP-based routing protocol, thus leading to a great deal of packet loss, the bad quality of service and the degradation of network performance. Due to the traditional IP network's undesirable capability of accurate fault detection for real-time applications like voice and for lack of intermittent recovery ability below second level, it is imperative to put fault detection and repairment for network into effect in accordance with the expansion of VoIP application. The self-recovery technology of MPLS network can, in response to the network fault, offer a reaction time less than IP layer and quickly detect the network fault and recover from that fault to remain the continuity of the network service. This paper, on the basis of in-depth discussion on the fault detection technique of the MPLS network, significantly reduces the detecting time of MPLS self-recovery to millisecond level by adopting Bidirectional Forwarding Detection (BFD) as the fault detection technique of MPLS network, and by careful design and realization of MPLS BFD as well as its application into multi-core router.
There needs to be a better scheme for fault recovery after the network is detected by MPLS. Of all the recovery schemes, there are two most famous ones, namely Makam and Haskin. Makam almost avoids the problem of packet reorder but suffers packets loss and relatively long protection time, while Haskin provides quick path switch but suffers severe problem of packet reorder as soon as the network traffic is redirected into the original working path to backup path after successful repair on working path. Thus, it has become the key point on how to develop a new type of fault recovery scheme so as to speed up the fault recovery while avoiding packet loss and packets disorder.
This paper offers a new kind of fault recovery scheme, namely the BFD-based fault recovery scheme on the basis of the research into the existing recovery schemes. The BFD-based fault recovery scheme possesses local repair mechanism to set up backup path so that the network traffic is quickly redirected into backup path once fault occurs, thus effectively avoiding packet loss and packet delay caused by traffic switch. This paper presents a new type of solution to the problem of packet disorder, namely utilizing disorder-control-label to control packets order and to avoid packet disorder. Tested in a real experimental network, the new type of fault recovery scheme is proved to be quick in fault recovery and effective in avoiding packet loss and packet delay.
目前基于IP路由协议的恢复机制至少需要几秒到几分钟的时间,这将导致大量分组的丢失,造成严重的服务质量问题以及网络性能的下降。传统IP网络对实时应用(如语音)进行准确故障检测方面的能力有限,并且不具备秒以下的间歇性故障修复功能。伴随着VoIP应用的激增,实现快速网络故障检测和修复越发显得必要。MPLS网络自愈恢复技术能够在故障发生后,提供比IP层更快的反应时间,可以快速的检测到网络故障并从故障中恢复过来,维持网络的服务连续性。本文对MPLS网络故障检测技术进行深入的研究,采用双向转发检测BFD作为MPLS网络的故障检测技术,详细的设计和实现MPLS BFD技术,并将MPLS BFD技术应用于多核网络设备,使MPLS网络故障检测时间达到毫秒级,大大缩短了MPLS自愈恢复的故障检测时间。
MPLS网络检测到故障后,需要有一个较好的方案进行故障恢复。目前比较著名的两种MPLS故障方案有Makam方案,Haskin方案。Makam方案的优点是几乎没有分组的重排序问题,但却有分组丢失和保护时间较长的缺点。Haskin方案提供快速的路径切换,但是当工作路径上故障清除后,在流量从备份路径切换回原工作路径时,数据分组的重排序问题比较严重。因此如何设计出一种新的故障恢复方案,使得故障恢复速度快,报文不丢失,并且报文不发生重排序仍然是目前研究的热点。
本文在对现有故障恢复方案研究的基础上,提出了一种新的故障恢复方案——基于BFD的故障恢复方案,新方案利用局部恢复机制,建立备份路径,当故障发生后流量快速切换到备份路径,减少了由于流量切换而造成的报文丢失及报文延迟。针对报文失序的问题,本方案提出了一种新的解决方法——利用失序控制标签实现了对流量顺序地控制,避免了流量切换带来的报文失序。经过组网测试,新方案具有较快的故障恢复速度,对报文丢失,报文失序现象都有明显地改善效果。
The traditional IP network now fails to serve the need of bearer real-time service in an effective way with its best-effort service against the backdrop of ever-increasing Internet service traffic and gradually diversified network service. There is an urgent need to guarantee the network continuity and Quality-of-Service (QoS) against network fault in order to obtain ideal service availability to help the automatic detection of network failure and recovery from that failure. As the core technology for the future backbone network, Multi-Protocol Label Switching (MPLS), by means of label-swapping technique, is expected to offer the Quality-of-Service (QoS) and traffic engineering more effective and potential than ever before. The MPLS network automatically resumes the interrupted service and maintains the robustness and efficiency of the network as a whole even in the case of node failure or link failure. The self-recovery technology of MPLS network is used to protect the network feasibility and stability in terms of fault detection technique and fault recovery.
It takes at least several seconds or even a couple of minutes for the current recovery mechanism of the IP-based routing protocol, thus leading to a great deal of packet loss, the bad quality of service and the degradation of network performance. Due to the traditional IP network's undesirable capability of accurate fault detection for real-time applications like voice and for lack of intermittent recovery ability below second level, it is imperative to put fault detection and repairment for network into effect in accordance with the expansion of VoIP application. The self-recovery technology of MPLS network can, in response to the network fault, offer a reaction time less than IP layer and quickly detect the network fault and recover from that fault to remain the continuity of the network service. This paper, on the basis of in-depth discussion on the fault detection technique of the MPLS network, significantly reduces the detecting time of MPLS self-recovery to millisecond level by adopting Bidirectional Forwarding Detection (BFD) as the fault detection technique of MPLS network, and by careful design and realization of MPLS BFD as well as its application into multi-core router.
There needs to be a better scheme for fault recovery after the network is detected by MPLS. Of all the recovery schemes, there are two most famous ones, namely Makam and Haskin. Makam almost avoids the problem of packet reorder but suffers packets loss and relatively long protection time, while Haskin provides quick path switch but suffers severe problem of packet reorder as soon as the network traffic is redirected into the original working path to backup path after successful repair on working path. Thus, it has become the key point on how to develop a new type of fault recovery scheme so as to speed up the fault recovery while avoiding packet loss and packets disorder.
This paper offers a new kind of fault recovery scheme, namely the BFD-based fault recovery scheme on the basis of the research into the existing recovery schemes. The BFD-based fault recovery scheme possesses local repair mechanism to set up backup path so that the network traffic is quickly redirected into backup path once fault occurs, thus effectively avoiding packet loss and packet delay caused by traffic switch. This paper presents a new type of solution to the problem of packet disorder, namely utilizing disorder-control-label to control packets order and to avoid packet disorder. Tested in a real experimental network, the new type of fault recovery scheme is proved to be quick in fault recovery and effective in avoiding packet loss and packet delay.
引文
[1]冯径.多协议标记交换技术.人民邮电出版社.2002:01-17.
[2]E.Rosen,A.Viswanatham,R.Callon."Multiprotocol Label Switching Architecture".RFC 3031.
[3]E.Rosen,D.Tappan,G.Fedorkow,Y Rekhter,D.Farinacci,T.Li,and A.Conta."MPLS Label Stack Encoding".RFC 3032,2001.2
[4]L.Andersson,P.Doolan,N.Feldman,A.Fredette,and B.Thomas."LDP Specification".RFC 3036,2000.8
[5]D.Awduche,L.Berger.,D.Gan.,T.Li.,V.Srinivasan.,G.Swallow."RSVP-TE:Extensions to RSVP for LSP Tunnels".RFC 3209,December 2001.
[6]V Ed.Shatma,F.Ed.Helistrand."Franmework for Multi-Protocol Label Swithing(MPLS)-based Recovery".RFC 3469,2003.2
[7]G.Swallow."MPLS advantages for traffic engineering".IEEE Communications Magazine,Volume 37,1999.12:4-57
[8]Haskin D.,Krishnan R.A method for setting an alternative label switched paths to handle fast reroute.IETF Draft,July 2001.
[9]Owens K.,Sharma v,Makam S.A path protection/restoration mechanism for MPLS networks.IETF Draft,July 2000.
[10]D.Katz.,D.Ward.Bidirectional Forwarding Detection.IETF Draft,March,2007.
[11]R.Aggarwal.,K.Kompella.,T.Nadeau.G.Swallow.BFD For MPLS LSPs.IETF Draft,March,2007.
[12]D.Katz.,D.Ward.,BFD for IPv4 and IPv6(Single Hop).IETF Draft,March,2007.
[13]D.Katz.,D.Ward.,BFD for Multihop Paths.IETF Draft,March,2007.
[14]D.Katz.,D.Ward.,Generic Application of BFD.IETF Draft,March,2007.
[15]吴江,慧玲.一代的IP骨干网络技术——多协议标记交换.民邮电出版社.2001:01-15.
[16]李晓东.MPLS技术与实现.电子工业出版社.2002:01-24.
[17]赵水宁,邵军力,赵伟.一种基于MPLS流量工程的快速重路由算法.系统仿真学报,2003,15(5):674-677.
[18]杨新宇,王鹏,曾明,郑守淇.一种新的基于MPLS的快速重路由模型.微电子学与计算机,2004,21(4):31-34.
[19]许先斌,王慧星,彭润年,一个基于快速重路由机制的MPLS故障恢复模型,计算机工程,2004,30(13):77-79.
[20]陈代寿.BFD高速路由故障检测.中国计算机报,2005年3月.
[21]徐迎晓,张根度.MPLS故障恢复机制研究.计算机工程,2002,28(4):273-275.
[22]黄维华.MPLS网络可靠性设计及恢复机制.通信与信息技术,2004年12月,32-35.
[23]杨鑫.MPLS网络的自愈恢复技术.电信快报,2005:38-40.
[24]王柱.MPLS网络故障恢复技术的应用研究.长沙通信技术学院学报,2007年3月:51-52.
[25]Sharma V.Framework for MPLS-based Recovery.Work inprogress,2002-05
[26]Ahn G,Jang J,Chun W.An Efficient Rerouting Scheme for MPLSbased Recovery and Its Performance Evaluation.Telecommunication Systems,2002,9
[27]李洪,朱英军.MPLS-TE流量工程系统设计(2).广东通信技术。2003,23(7):01-10.
[28]Huang Changcheng.Building reliable MPLS networks using a path protection mechanism[J].IEEE Communications Magazine,2002
[29]康剑,曹阳,葛非,王悦伟.一种新的MPLS网络故障恢复算法.计算机应用研究,2005年8月:207-209.
[30]K.Kompella.,G.Swallow.,Detecting Multi-Protocol Label Switched(MPLS)Data Plane Failures.RFC4379,February 2006.
[31]P.Pan,Ed.G.Swallow,Ed.A.Atlas,Ed.Fast Reroute Extensions to RSVP-TE for LSP Tunnels.RFC4090,May 2005.
[32]Scott Poretsky,Rajesh Khanna,R Papneja,Bench Marking Methodology for MPLS Protection Mechanisms[J]1 Internet Draft,April 2001.
[33]V.Sharma,Ed.F.Hellstrand,Ed.Framework for Multi-Protocol Label Switching(MPLS)-based Recovery.RFC3469,February 2003.
[34]Emre Yetginer,Ezhan Karasan,Robust Path Design Algorithms for Traffic Engineering with Restoration in MPLS Networks[C]1 IEEE(ISCC'02),2001.
[35]王华,田国会,孙亚民,王珩.基于MPLS的带宽保证的N-to-1保护方法.小型微型计算机系统,2004年5月:927-929.
[36]杨宗凯,谭贤四,陈京文,马娅婕.一种基于m:n策略的MPLS网络故障恢复性能评估方法.通信学报,2003年12月:133-140.
[37]谢晖,曹振海,钱松荣.MPLS网络的故障管理.计算机工程与设计.2004,25(5):746-749.
[38]Huang Changcheng.Building reliable MPLS networks using a path protection mechanism.IEEE Communications Magazine.2002.
[39]李彬,陈向东.一种MPLS网络的故障恢复方案.微电子学与计算机.2007,24(01):126-129.
[40]李彬,陈向东.基于比流量工程的重路由算法研究.计算机工程.2006,45(31):153-156.
[41]李彬,陈向东.一种MPLS的故障恢复方案.计算机应用研究.2007, 24(02):90-100.
[42]Wang hua,Sun Yamin.The QoS Model and Realization of Connecting Enterprise Network to Different ISP via Proxy Servers.IEEE 2001 International Conference on Info-tech and Info-net Proceedings.2001:605-609,IEEE press.ISSN/ISBN:17-900081-58-5.ISTP 收录,IDS No.BU94X.
[43]王华,王晰,孙亚民.基于MPLS-DiffServ的N-to-1保护方法.计算机工程与应用.2003,20:165-232.
[44]Wang Hua,Sun Yamin et al.Research on Multiprotocol Label Switching (MPLS)Architecture.Proceedings of 4″′ International Conference on Computer-Aided Industrial Design and Conceptual Design.2001:729-735.International Academic Publishers World Publishing Corporation.ISBN:7-5062-5182-5.
[45]王华,孙亚民.使用MPLS解决网络最大流问题的方法.南京理工大学学报.2003,27(1):20-23.
[46]Gray,E.w.著 罗志祥 朱志实 黄本雄译.MPLS实现技术.电子工业出版社.2003:01-20.
[47]Ivan Pepelnjak,CCIE No.1354 Jim Guichard,CClE No.2069 Jeff Spcar著.MPLS和VPN体系结构.信达工作室译.人民邮电出版社.2001:03-49.
[48]Eric Osborne,Ajay Simha著.基于MPLS的流量工程.张辉,卢炜译.北京:人民邮电出版社,2003:06-196.
[49]T.H.Oh,T.M.Chen,and J.L.Kennington,"Fault restoration and spare capacity allocation with QoS constraints for MPLS networks",IEEE Global Telecommunications Conference,Volume3,Dec 2000:1731-1735.
[50]D.Gan,"A method for MPLS LSP fast-reroute using RSVP detours,"Internet Draft(draft-gan-fast-reroute-OO.txt),April 2001.
[51]B.G.Jozsa,D.Orincsay,and,A.Kern,"Surviving multiple network failures using shared backup path protection" Proceedings of the Eighth IEEE International Symposium on Computers and Communication,2003:1333-1340.
[52]T.M.Chen and T.H.Oh,"Reliable services in MPLS",IEEE Communications Magazine,Volume:37 Issue:12,Dec.1999.
[53]R.Braden,Ed.,L.Zhang.,S.Berson.,S.Herzog.,S.Jamin.,"Resource ReSerVation Protocol(RSVP)--Version 1 Functional Specification".RFC2205.September 1997.
[54]D.Katz.,K.Kompella.,D.Yeung.,"Traffic Engineering(TE)Extensions to OSPF Version2".RFC 3630.September 2003.
[55]发现路由器转发故障的BFD.网络世界.2005年03月21日.
[56]E.Rosen.,Y.Rekhter."BGP/MPLS IP Virtual Private Networks(VPNs)".RFC4364.February,2006.
[57]L.Martini.,E.Rosen.,E.Rosen.,N.El-Aawar.,T.Smith.,G.Heron."Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)".RFC4447.April,2006.
[2]E.Rosen,A.Viswanatham,R.Callon."Multiprotocol Label Switching Architecture".RFC 3031.
[3]E.Rosen,D.Tappan,G.Fedorkow,Y Rekhter,D.Farinacci,T.Li,and A.Conta."MPLS Label Stack Encoding".RFC 3032,2001.2
[4]L.Andersson,P.Doolan,N.Feldman,A.Fredette,and B.Thomas."LDP Specification".RFC 3036,2000.8
[5]D.Awduche,L.Berger.,D.Gan.,T.Li.,V.Srinivasan.,G.Swallow."RSVP-TE:Extensions to RSVP for LSP Tunnels".RFC 3209,December 2001.
[6]V Ed.Shatma,F.Ed.Helistrand."Franmework for Multi-Protocol Label Swithing(MPLS)-based Recovery".RFC 3469,2003.2
[7]G.Swallow."MPLS advantages for traffic engineering".IEEE Communications Magazine,Volume 37,1999.12:4-57
[8]Haskin D.,Krishnan R.A method for setting an alternative label switched paths to handle fast reroute.IETF Draft
[9]Owens K.,Sharma v,Makam S.A path protection/restoration mechanism for MPLS networks.IETF Draft
[10]D.Katz.,D.Ward.Bidirectional Forwarding Detection.IETF Draft
[11]R.Aggarwal.,K.Kompella.,T.Nadeau.G.Swallow.BFD For MPLS LSPs.IETF Draft
[12]D.Katz.,D.Ward.,BFD for IPv4 and IPv6(Single Hop).IETF Draft
[13]D.Katz.,D.Ward.,BFD for Multihop Paths.IETF Draft
[14]D.Katz.,D.Ward.,Generic Application of BFD.IETF Draft
[15]吴江,慧玲.一代的IP骨干网络技术——多协议标记交换.民邮电出版社.2001:01-15.
[16]李晓东.MPLS技术与实现.电子工业出版社.2002:01-24.
[17]赵水宁,邵军力,赵伟.一种基于MPLS流量工程的快速重路由算法.系统仿真学报,2003,15(5):674-677.
[18]杨新宇,王鹏,曾明,郑守淇.一种新的基于MPLS的快速重路由模型.微电子学与计算机,2004,21(4):31-34.
[19]许先斌,王慧星,彭润年,一个基于快速重路由机制的MPLS故障恢复模型,计算机工程,2004,30(13):77-79.
[20]陈代寿.BFD高速路由故障检测.中国计算机报,2005年3月.
[21]徐迎晓,张根度.MPLS故障恢复机制研究.计算机工程,2002,28(4):273-275.
[22]黄维华.MPLS网络可靠性设计及恢复机制.通信与信息技术,2004年12月,32-35.
[23]杨鑫.MPLS网络的自愈恢复技术.电信快报,2005:38-40.
[24]王柱.MPLS网络故障恢复技术的应用研究.长沙通信技术学院学报,2007年3月:51-52.
[25]Sharma V.Framework for MPLS-based Recovery.Work inprogress
[26]Ahn G,Jang J,Chun W.An Efficient Rerouting Scheme for MPLSbased Recovery and Its Performance Evaluation.Telecommunication Systems,2002,9
[27]李洪,朱英军.MPLS-TE流量工程系统设计(2).广东通信技术。2003,23(7):01-10.
[28]Huang Changcheng.Building reliable MPLS networks using a path protection mechanism[J].IEEE Communications Magazine,2002
[29]康剑,曹阳,葛非,王悦伟.一种新的MPLS网络故障恢复算法.计算机应用研究,2005年8月:207-209.
[30]K.Kompella.,G.Swallow.,Detecting Multi-Protocol Label Switched(MPLS)Data Plane Failures.RFC4379,February 2006.
[31]P.Pan,Ed.G.Swallow,Ed.A.Atlas,Ed.Fast Reroute Extensions to RSVP-TE for LSP Tunnels.RFC4090,May 2005.
[32]Scott Poretsky,Rajesh Khanna,R Papneja,Bench Marking Methodology for MPLS Protection Mechanisms[J]1 Internet Draft,April 2001.
[33]V.Sharma,Ed.F.Hellstrand,Ed.Framework for Multi-Protocol Label Switching(MPLS)-based Recovery.RFC3469,February 2003.
[34]Emre Yetginer,Ezhan Karasan,Robust Path Design Algorithms for Traffic Engineering with Restoration in MPLS Networks[C]1 IEEE(ISCC'02),2001.
[35]王华,田国会,孙亚民,王珩.基于MPLS的带宽保证的N-to-1保护方法.小型微型计算机系统,2004年5月:927-929.
[36]杨宗凯,谭贤四,陈京文,马娅婕.一种基于m:n策略的MPLS网络故障恢复性能评估方法.通信学报,2003年12月:133-140.
[37]谢晖,曹振海,钱松荣.MPLS网络的故障管理.计算机工程与设计.2004,25(5):746-749.
[38]Huang Changcheng.Building reliable MPLS networks using a path protection mechanism.IEEE Communications Magazine.2002.
[39]李彬,陈向东.一种MPLS网络的故障恢复方案.微电子学与计算机.2007,24(01):126-129.
[40]李彬,陈向东.基于比流量工程的重路由算法研究.计算机工程.2006,45(31):153-156.
[41]李彬,陈向东.一种MPLS的故障恢复方案.计算机应用研究.2007, 24(02):90-100.
[42]Wang hua,Sun Yamin.The QoS Model and Realization of Connecting Enterprise Network to Different ISP via Proxy Servers.IEEE 2001 International Conference on Info-tech and Info-net Proceedings.2001:605-609,IEEE press.ISSN/ISBN:17-900081-58-5.ISTP 收录,IDS No.BU94X.
[43]王华,王晰,孙亚民.基于MPLS-DiffServ的N-to-1保护方法.计算机工程与应用.2003,20:165-232.
[44]Wang Hua,Sun Yamin et al.Research on Multiprotocol Label Switching (MPLS)Architecture.Proceedings of 4″′ International Conference on Computer-Aided Industrial Design and Conceptual Design.2001:729-735.International Academic Publishers World Publishing Corporation.ISBN:7-5062-5182-5.
[45]王华,孙亚民.使用MPLS解决网络最大流问题的方法.南京理工大学学报.2003,27(1):20-23.
[46]Gray,E.w.著 罗志祥 朱志实 黄本雄译.MPLS实现技术.电子工业出版社.2003:01-20.
[47]Ivan Pepelnjak,CCIE No.1354 Jim Guichard,CClE No.2069 Jeff Spcar著.MPLS和VPN体系结构.信达工作室译.人民邮电出版社.2001:03-49.
[48]Eric Osborne,Ajay Simha著.基于MPLS的流量工程.张辉,卢炜译.北京:人民邮电出版社,2003:06-196.
[49]T.H.Oh,T.M.Chen,and J.L.Kennington,"Fault restoration and spare capacity allocation with QoS constraints for MPLS networks",IEEE Global Telecommunications Conference,Volume3,Dec 2000:1731-1735.
[50]D.Gan,"A method for MPLS LSP fast-reroute using RSVP detours,"Internet Draft(draft-gan-fast-reroute-OO.txt),April 2001.
[51]B.G.Jozsa,D.Orincsay,and,A.Kern,"Surviving multiple network failures using shared backup path protection" Proceedings of the Eighth IEEE International Symposium on Computers and Communication,2003:1333-1340.
[52]T.M.Chen and T.H.Oh,"Reliable services in MPLS",IEEE Communications Magazine,Volume:37 Issue:12,Dec.1999.
[53]R.Braden,Ed.,L.Zhang.,S.Berson.,S.Herzog.,S.Jamin.,"Resource ReSerVation Protocol(RSVP)--Version 1 Functional Specification".RFC2205.September 1997.
[54]D.Katz.,K.Kompella.,D.Yeung.,"Traffic Engineering(TE)Extensions to OSPF Version2".RFC 3630.September 2003.
[55]发现路由器转发故障的BFD.网络世界.2005年03月21日.
[56]E.Rosen.,Y.Rekhter."BGP/MPLS IP Virtual Private Networks(VPNs)".RFC4364.February,2006.
[57]L.Martini.,E.Rosen.,E.Rosen.,N.El-Aawar.,T.Smith.,G.Heron."Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)".RFC4447.April,2006.