Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563911
L. Tamási, D. Orincsay, B. Józsa, G. Magyar
This paper addresses the issue of survivable voice over IP (VoIP) network design. In the applied model the whole VoIP network is divided into two logical components: the access network and the transport network. The access network consists of VoIP end-points, which connect to the transport network through edge routers serving as gateways. Thus, one task of the design process is to assign gateways to the VoIP end-points. To assure security and availability for the VoIP traffic, a virtual private network (VPN) is assumed as transport network in this paper; therefore, the other task is to specify the transport VPN in the most economical way, while also taking the possible failures of transport network elements into consideration. Assuming a single failure at a time, the survivability of the VoIP network can be assured by assigning two gateways, namely a primary and a backup one, to each VoIP end-point, and calculating two disjoint paths between each pair of gateways. The two tasks of survivable VoIP network design can be solved separately; however, in this paper, a novel solution is proposed in which the edge router assignment process takes both the objective function of VPN specification and the issues of survivability into consideration. Multiple methods realizing the novel approach are presented, which are based on the paradigms of evolutionary algorithms and simulated annealing. The performance of the presented methods is evaluated with the help of simulations, using a well-known greedy algorithm as reference. It is shown that the proposed methods outperform the reference algorithm significantly in the simulation scenarios investigated.
{"title":"Design of survivable VPN based VoIP networks","authors":"L. Tamási, D. Orincsay, B. Józsa, G. Magyar","doi":"10.1109/DRCN.2005.1563911","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563911","url":null,"abstract":"This paper addresses the issue of survivable voice over IP (VoIP) network design. In the applied model the whole VoIP network is divided into two logical components: the access network and the transport network. The access network consists of VoIP end-points, which connect to the transport network through edge routers serving as gateways. Thus, one task of the design process is to assign gateways to the VoIP end-points. To assure security and availability for the VoIP traffic, a virtual private network (VPN) is assumed as transport network in this paper; therefore, the other task is to specify the transport VPN in the most economical way, while also taking the possible failures of transport network elements into consideration. Assuming a single failure at a time, the survivability of the VoIP network can be assured by assigning two gateways, namely a primary and a backup one, to each VoIP end-point, and calculating two disjoint paths between each pair of gateways. The two tasks of survivable VoIP network design can be solved separately; however, in this paper, a novel solution is proposed in which the edge router assignment process takes both the objective function of VPN specification and the issues of survivability into consideration. Multiple methods realizing the novel approach are presented, which are based on the paradigms of evolutionary algorithms and simulated annealing. The performance of the presented methods is evaluated with the help of simulations, using a well-known greedy algorithm as reference. It is shown that the proposed methods outperform the reference algorithm significantly in the simulation scenarios investigated.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"326 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132982363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563903
T. Cinkler, Diana Mesko, A. Mitcsenkov, G. Viola
We propose two algorithms for dynamic routing of guaranteed bandwidth pipes with shared protection that provide low blocking through thrifty resource usage. We assume that a single working path can be protected by one or multiple protection paths, which are partially or fully disjoint from the working path. This allows better capacity re-use (i.e., better capacity sharing among protection paths). Furthermore, the resources of a working path affected by a failure can be re-used by the protection paths. The main feature of the proposed protection rearrangement framework is that since the protection paths do not carry any traffic until a failure they can be adaptively rerouted (rearranged) as the traffic and network conditions change. This steady reoptimisation of protection paths leads to lower usage of resources and therefore higher throughput and lower blocking. The other novelty we propose in this paper is a modelling trick referred to as LD: link doubling that allows distinguishing the sharable part of the link capacity from the free capacity in case when multiple protection paths are being rerouted simultaneously. LD allows finding optimal routing of shared protection paths for the case of any single link failure! The obtained results can be used for routing with protection in SDH/SONET, ngSDH/SONET, ATM, MPLS, WR-DWDM (including ASTN/GMPLS) and other networks.
{"title":"Adaptive shared protection rearrangement","authors":"T. Cinkler, Diana Mesko, A. Mitcsenkov, G. Viola","doi":"10.1109/DRCN.2005.1563903","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563903","url":null,"abstract":"We propose two algorithms for dynamic routing of guaranteed bandwidth pipes with shared protection that provide low blocking through thrifty resource usage. We assume that a single working path can be protected by one or multiple protection paths, which are partially or fully disjoint from the working path. This allows better capacity re-use (i.e., better capacity sharing among protection paths). Furthermore, the resources of a working path affected by a failure can be re-used by the protection paths. The main feature of the proposed protection rearrangement framework is that since the protection paths do not carry any traffic until a failure they can be adaptively rerouted (rearranged) as the traffic and network conditions change. This steady reoptimisation of protection paths leads to lower usage of resources and therefore higher throughput and lower blocking. The other novelty we propose in this paper is a modelling trick referred to as LD: link doubling that allows distinguishing the sharable part of the link capacity from the free capacity in case when multiple protection paths are being rerouted simultaneously. LD allows finding optimal routing of shared protection paths for the case of any single link failure! The obtained results can be used for routing with protection in SDH/SONET, ngSDH/SONET, ATM, MPLS, WR-DWDM (including ASTN/GMPLS) and other networks.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124862826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563889
T. Cinkler, A. Kern, I. Moldován
Ethernet is being increasingly employed in metro networks. Ethernet gives routing schemes and protocols for building up trees, for instance STP, RSTP and MSTP. It also implies simple restoration mechanisms. In this paper we propose an optimization framework, where the Ethernet MSTP trees are protected and QoS is guaranteed even after a failure. The optimization is based not only on the topology, but it also takes traffic conditions and QoS constraints into account. The numerical results show that the proposed optimization significantly increases the throughput of the network. The best result can be achieved when preemption is assumed, i.e., when the best effort traffic may remain unprotected, but not the high priority one. This way high throughput can be realized at normal operation, while it still protects prioritized traffic in case of a failure. Furthermore, protection mechanisms act faster than the standard restoration mechanism resulting shorter out-of-service times, and therefore higher availability.
{"title":"Optimized QoS protection of Ethernet trees","authors":"T. Cinkler, A. Kern, I. Moldován","doi":"10.1109/DRCN.2005.1563889","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563889","url":null,"abstract":"Ethernet is being increasingly employed in metro networks. Ethernet gives routing schemes and protocols for building up trees, for instance STP, RSTP and MSTP. It also implies simple restoration mechanisms. In this paper we propose an optimization framework, where the Ethernet MSTP trees are protected and QoS is guaranteed even after a failure. The optimization is based not only on the topology, but it also takes traffic conditions and QoS constraints into account. The numerical results show that the proposed optimization significantly increases the throughput of the network. The best result can be achieved when preemption is assumed, i.e., when the best effort traffic may remain unprotected, but not the high priority one. This way high throughput can be realized at normal operation, while it still protects prioritized traffic in case of a failure. Furthermore, protection mechanisms act faster than the standard restoration mechanism resulting shorter out-of-service times, and therefore higher availability.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122845614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563890
P. Chołda, K. Wajda, A. Jajszczyk, János Tapolcai, T. Cinkler, S. Bodamer, D. Colle, G. Ferraris
The paper proposes a novel approach to service differentiation using both 'classical' QoS parameters and novel resilience-oriented QoR (quality of resilience) parameters. In this concept, two network states are defined, 'fully operational' and 'after failure', enabling the operators to define precisely the QoS guarantees before and after a failure occurrence, and to distribute information about failure severity to a customer/user. As such, a combined QoS/QoR approach can be seen as a kind of an 'insurance' for the customer, i.e. sharing the risk of a failure occurrence and enabling selective treatment of individual services. In the 'after failure' state, the failure is unverifiable for the user, and a service with a lower QoS guarantee is provided at possibly reduced costs.
{"title":"Considerations about service differentiation using a combined QoS/QoR approach","authors":"P. Chołda, K. Wajda, A. Jajszczyk, János Tapolcai, T. Cinkler, S. Bodamer, D. Colle, G. Ferraris","doi":"10.1109/DRCN.2005.1563890","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563890","url":null,"abstract":"The paper proposes a novel approach to service differentiation using both 'classical' QoS parameters and novel resilience-oriented QoR (quality of resilience) parameters. In this concept, two network states are defined, 'fully operational' and 'after failure', enabling the operators to define precisely the QoS guarantees before and after a failure occurrence, and to distribute information about failure severity to a customer/user. As such, a combined QoS/QoR approach can be seen as a kind of an 'insurance' for the customer, i.e. sharing the risk of a failure occurrence and enabling selective treatment of individual services. In the 'after failure' state, the failure is unverifiable for the user, and a service with a lower QoS guarantee is provided at possibly reduced costs.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122860951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563905
Xubin Luo, Bin Wang
We study the diverse routing problem in WDM optical networks with SRLG failures. We consider a more general case of SRLG failures than those considered in Datta and Somani (2004) and Doucette and Grover (2002). All the optical links in an SRLG share a common endpoint. In addition, a link can belong to arbitrary number of SRLG groups and an SRLG may include more than two links. We develop a polynomial time optimal algorithm to find a pair of least cost SRLG-disjoint paths between a source and a destination. We prove the correctness of the algorithm which is also shown to be more time efficient than the graph transformation based algorithm of Datta and Somani (2004).
{"title":"Diverse routing in WDM optical networks with shared risk link group (SRLG) failures","authors":"Xubin Luo, Bin Wang","doi":"10.1109/DRCN.2005.1563905","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563905","url":null,"abstract":"We study the diverse routing problem in WDM optical networks with SRLG failures. We consider a more general case of SRLG failures than those considered in Datta and Somani (2004) and Doucette and Grover (2002). All the optical links in an SRLG share a common endpoint. In addition, a link can belong to arbitrary number of SRLG groups and an SRLG may include more than two links. We develop a polynomial time optimal algorithm to find a pair of least cost SRLG-disjoint paths between a source and a destination. We prove the correctness of the algorithm which is also shown to be more time efficient than the graph transformation based algorithm of Datta and Somani (2004).","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134217175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563923
R. Zhao, Sebastian Goetze, R. Lehnert
Hybrid fibre-VDSL (Very high speed Digital Subscriber Line) access network is one of the most efficient strategies to transfer broadband services to end users. However, the planning of hybrid access networks is a NP-hard problem. During the planning and optimisation approach, the network costs, time delay and reliability have to be taken into account. This paper presents a novel planning tool for hybrid fibre-VDSL access networks with visualisation. Simulated Annealing, Tabu Search and Genetic Algorithms, as the effective heuristic algorithms, have been investigated and embedded into the planning tool to obtain optimal topologies.
{"title":"A visual planning tool for hybrid fibre VDSL access networks with heuristic algorithms","authors":"R. Zhao, Sebastian Goetze, R. Lehnert","doi":"10.1109/DRCN.2005.1563923","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563923","url":null,"abstract":"Hybrid fibre-VDSL (Very high speed Digital Subscriber Line) access network is one of the most efficient strategies to transfer broadband services to end users. However, the planning of hybrid access networks is a NP-hard problem. During the planning and optimisation approach, the network costs, time delay and reliability have to be taken into account. This paper presents a novel planning tool for hybrid fibre-VDSL access networks with visualisation. Simulated Annealing, Tabu Search and Genetic Algorithms, as the effective heuristic algorithms, have been investigated and embedded into the planning tool to obtain optimal topologies.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133371928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563874
G. Grammel
With the concept of multi region networks resiliency across switching layers can be implemented in a standardized way. Multi-layer resiliency based on a MRN control plane allows to simplify provisioning and recovery on integrated networks across different transport layers. By exploiting these mechanisms an efficient resilience mechanism in multi layer networks is realized.
{"title":"Control plane design for multi-layer resilience","authors":"G. Grammel","doi":"10.1109/DRCN.2005.1563874","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563874","url":null,"abstract":"With the concept of multi region networks resiliency across switching layers can be implemented in a standardized way. Multi-layer resiliency based on a MRN control plane allows to simplify provisioning and recovery on integrated networks across different transport layers. By exploiting these mechanisms an efficient resilience mechanism in multi layer networks is realized.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125214432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563891
M. Morawski
In the paper we present the new method of multipath routing that supports the quality of service (QoS). The idea of the method is based on the well-known minimum delay routing principle [R. Gallager (1977)], but the routing problem considered in the paper applies to the most frequently encountered case of communication networks with the TCP-traffic dominating in all links, rather than UDP multimedia traffic. In our approach we assume that the values of metrics in all links are not known exactly, but we consider them as values with uncertainty. Such approach, together with associated forwarding method allows to assimilate well known routing algorithms to the optimal behavior i.e. the best possible throughput for data streams. In this paper only unidirectional routing is considered.
{"title":"Uncertain metrics applied to QoS multipath routing","authors":"M. Morawski","doi":"10.1109/DRCN.2005.1563891","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563891","url":null,"abstract":"In the paper we present the new method of multipath routing that supports the quality of service (QoS). The idea of the method is based on the well-known minimum delay routing principle [R. Gallager (1977)], but the routing problem considered in the paper applies to the most frequently encountered case of communication networks with the TCP-traffic dominating in all links, rather than UDP multimedia traffic. In our approach we assume that the values of metrics in all links are not known exactly, but we consider them as values with uncertainty. Such approach, together with associated forwarding method allows to assimilate well known routing algorithms to the optimal behavior i.e. the best possible throughput for data streams. In this paper only unidirectional routing is considered.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128673518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563886
L. Nederlof, David Mirto, S. Ten, M. Gunkel, D. Breuer, H. Reiner, H. Cremer, R. Freund, C. Caspar, F. Raub
This paper describes a study of the value of dispersion-managed fiber in a German backbone network and a cost optimization over amplifier span length.
本文研究了分散管理光纤在德国骨干网中的价值，并对放大器跨长的成本进行了优化。
{"title":"Cost optimization study using dispersion-managed fiber in a German backbone network","authors":"L. Nederlof, David Mirto, S. Ten, M. Gunkel, D. Breuer, H. Reiner, H. Cremer, R. Freund, C. Caspar, F. Raub","doi":"10.1109/DRCN.2005.1563886","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563886","url":null,"abstract":"This paper describes a study of the value of dispersion-managed fiber in a German backbone network and a cost optimization over amplifier span length.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127058255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563843
Fahad R. Dogar, Z. Uzmi, Shahab Baqai
The authors proposed an architecture for MPLS restoration routing of DiffServ traffic. This architecture, namely per class aggregate information with preemption (CAIP), facilitates provisioning of two key QoS features for multimedia traffic: prioritized guaranteed bandwidth and fast restoration in the event of an element failure. The CAIP architecture is scalable and requires propagating only per-class aggregate link usage information; such information can be readily piggybacked on link state routing packets using traffic engineering extensions to link state routing protocols (Katz et. al). CAIP results in improved bandwidth sharing compared to simple aggregate information scenario (SAIS), resulting in fewer LSP rejected requests and a greater amount of active bandwidth placed on the network. On average, CAIP rejects 881 LSP requests compared to 1010 rejected LSP requests in SAIS for a typical ISP network. Similarly, CAIP is able to place 220 units of bandwidth compared to 180 units of bandwidth placed in SAIS, thus showing an average improvement of about 22%. CAIP allows precise computation of preemptable bandwidth for an arbitrary set of prioritization requirements put forth by the service providers. A case study of service provider requirements and computation of preemptable bandwidth for those requirements were presented. CAIP can be integrated with those restoration routing schemes that make use of propagating aggregate link usage information. Furthermore, existing preemption schemes can be used with CAIP in order to decide the actual LSPs which need to be preempted.
提出了一种用于diffserver流量MPLS恢复路由的体系结构。这种架构，即带抢占的每类聚合信息(CAIP)，有助于为多媒体流量提供两个关键的QoS特性:优先保证带宽和元素故障时的快速恢复。CAIP体系结构是可伸缩的，只需要传播每个类的聚合链接使用信息;这些信息可以很容易地搭载在链路状态路由数据包上，使用流量工程扩展到链路状态路由协议(Katz等)。与SAIS (simple aggregate information scenario)方案相比，CAIP方案改善了带宽共享，减少了LSP拒绝请求，增加了网络上的活动带宽。在典型ISP网络中，CAIP平均拒绝881个LSP请求，而SAIS平均拒绝1010个LSP请求。同样，CAIP能够放置220个单位的带宽，而SAIS放置180个单位的带宽，因此显示出大约22%的平均改进。CAIP允许为服务提供商提出的任意一组优先级要求精确计算可抢占带宽。给出了服务提供商需求的实例研究和针对这些需求的可抢占带宽的计算。CAIP可以与那些利用传播聚合链路使用信息的恢复路由方案集成。此外，现有的抢占方案可以与CAIP一起使用，以确定实际需要抢占的lsp。
{"title":"CAIP: a restoration routing architecture for DiffServ aware MPLS traffic engineering","authors":"Fahad R. Dogar, Z. Uzmi, Shahab Baqai","doi":"10.1109/DRCN.2005.1563843","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563843","url":null,"abstract":"The authors proposed an architecture for MPLS restoration routing of DiffServ traffic. This architecture, namely per class aggregate information with preemption (CAIP), facilitates provisioning of two key QoS features for multimedia traffic: prioritized guaranteed bandwidth and fast restoration in the event of an element failure. The CAIP architecture is scalable and requires propagating only per-class aggregate link usage information; such information can be readily piggybacked on link state routing packets using traffic engineering extensions to link state routing protocols (Katz et. al). CAIP results in improved bandwidth sharing compared to simple aggregate information scenario (SAIS), resulting in fewer LSP rejected requests and a greater amount of active bandwidth placed on the network. On average, CAIP rejects 881 LSP requests compared to 1010 rejected LSP requests in SAIS for a typical ISP network. Similarly, CAIP is able to place 220 units of bandwidth compared to 180 units of bandwidth placed in SAIS, thus showing an average improvement of about 22%. CAIP allows precise computation of preemptable bandwidth for an arbitrary set of prioritization requirements put forth by the service providers. A case study of service provider requirements and computation of preemptable bandwidth for those requirements were presented. CAIP can be integrated with those restoration routing schemes that make use of propagating aggregate link usage information. Furthermore, existing preemption schemes can be used with CAIP in order to decide the actual LSPs which need to be preempted.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122211863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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