• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.358-364
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• 2007

This paper suggests MPLS restoration method that use an aggregation tree. For the restoration of the MPLS network, this paper presents a scheme that reconstruct multiple path through aggregation tree that grow from many node to a target node. Contrary to a multicast tree where a message that send at one node is passed to a group of node, an aggregation tree is a tree that data is passed from many node to one destination node. Through an experiment we confirmed that the restoration scheme that uses aggregation tree shows taster speed comparing with the existing other restoration scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.11
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• pp.1-11
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• 2002

To increase network survivability and to guarantee reliable services in MPLS networks, when failures occur either at any link or node of a working path, traffics on the failed path should be switched to other restoration paths. In this paper, we propose a path restoration method using duplication of working paths for link failure and its associated failure detection method, which utilizes OAM cells when all the duplicated links or nodes of the path failed. We analyze the performance of the proposed restoration method and show that especially the method is very efficient to restore high priority traffics. Also, through simulation we prove that the proposed restoration method is superior in performance to several existing methods suggested so far.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.401-408
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• 2005

We propose a new MPLS restoration scheme that uses network resources more efficiently and minimizes the backup path cost effectively. Contrary to other restoration strategies, the proposed restoration scheme starts the recovery action at the selected node of a working LSP. At LSP setup, the working and backup path cost is evaluated and the starting node of restoration is designated. By doing so, the restoration speed could be further increased and resource utilization could be maximized. We simulated the proposed scheme and compared with other restoration and protection schemes. The result shows that our scheme can provide fast restoration with acceptable delay and loss characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.61-64
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• 2007

MPLS networks architectures have been prevailed as scalable approach to provide quality of service in the Internet. Many researches have been mainly focused on scalability and multi-path calculation scheme for failure restoration. However, the MPLS network have an scalability problem about traffic, and the existing failure restoration methods are wasted resources, and it has the problem that loss of a packet by a lot of delay occurs in too. Therefore in this paper, we propose a H-MPLS (Hierachical-Multiprotocol Label Switching)network for rapidly failure restorations and effective management of network extended. The proposed H-MPLS Network apply LSP multi-path routing algorithm and consists of several MPLS. After comparing the performance among the existing failure restoration methods with various network models, we use NS simulator in order to analyze the performance. Finally, we present an improvement scheme of the efficiency and scalability.

• Journal of Internet Computing and Services
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• v.4 no.2
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• pp.1-9
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• 2003

Path restoration, which is needed to increase network survivability in MPLS networks, is a technology of supplying reliable service by delivering the traffics through restoring the paths when links or nodes of a working path are failed. In this paper, we propose a path restoration method using duplication of working paths for link failure as a method of restoring paths for the high priority traffics. The existing path restoration method transmits the traffics to the path restoration uniformly in regardless of the priority while link obstacle. It has a problem to take a long time to restore the connection of the high priority traffics. On the other hand, the suggested restoration method establishes the duplication path for the working path, which transmits the high priority traffics and transmit the traffics through the duplication path. It has a strong point to restore the connection quickly. Also, through simulation we analyze the performance of the restoration system using the duplication path and prove that the proposed restoration method is superior in performance to the existing restoration methods regarding to the high priority traffics.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.49-58
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• 2010

In this paper, we present a methodology for fast segment restoration under multiple simultaneous link failures in mesh-type MPLS networks. The salient feature of the methodology is that both resilience and QoS constraint conditions have been taken into account for fast segment restoration. For fast restoration, a sufficient condition for testing the existence of backup segments with guaranteed-resilience has been derived for a mesh-type MPLS network. The algorithms for constructing backup segments which can meet both resilience and QoS constraint conditions are then presented with illustrating examples. Finally, simulation has been done to show the efficiency of the proposed segment restoration algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.956-966
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• 2004

Nowadays, NGN(Next Generation Network) is evolving into network with packet based QoS.\ulcorner This paper presents the recovery method as a selecting way of more efficient path in MPLS network that reduces the service interruption time. In order to increase the efficiency of usage of recovering resource which is one of major functions of disorder recovering, it opens the state information of each Node both to fault detector and bandwidth broker so that it reduces message transmission time for recovery when functional disorder occurs. in addition, by effective management and adjustment of required bandwidth of entire network depending on the changes of traffic load, it improves the efficiency of bandwidth usage. and in MPLS network supporting priority selection function, it allocates domains depending on the traffic relating to priority order to the entire network so that\ulcorner it efficiently allocates proper resources to the restoring process between the entry and the end for the traffic of high priority and for low priority traffic, it restores path oかy inside disordered domain. by doing this, it reduces resetting time and unnecessary massage transmission.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.5
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• pp.11-18
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• 2004

In this paper, we propose the alternative LSP allocation for MPLS networks required more confidence. In the first place, we must classify the user traffics by the QoS parameter. We assigned altermative LSPs on realtime traffics and then allocated alternative LSPs of non-realtime traffics. The proposed algorithm can provide more confidential alternative LSP by priority method for relatively high cost realtime traffic error. And the proposed algorithm can improve the shortage of network resources what is occured by using a few links when altermative LSPs are setup. The validity of the proposed algorithm has been justified in performance by analysis through simulation results using the program tool and comparison with conventional methods. Also, that improves 9% more than existing method in the recovery ratio-one is 89%, the other is 98%, respectively.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.233-241
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• 2004

In this paper, we propose a packet-lossless fast rerouting scheme at a link/node fault in MPLS (Multiprotocol Label Switching) network with minimized accumulated buffer delay problem at ingress node. The proposed scheme uses a predefined, alternative LSP (Label Switched Path) In order to restore user traffic. We propose two restoration approaches. In the first approach, an alternative LSP is initially allocated with more bandwidth than the protected working LSP during the failure recovery phase. After the failure recovery, the excessively allocated bandwidth of the alternative LSP is readjusted to the bandwidth of the working LSP. In the second approach, we reduce the length of protected working LSP by using segment-based restoration. The proposed approaches have merits of (ⅰ) no buffer delay problem after failure recovery at ingress node, and (ⅱ) the smaller required buffer size at the ingress node than the previous approach.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1595-1598
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• 2002

네트워크 장애로 인한 인터넷 서비스 품질의 저하는 사용자와 서비스 제공자에게 여러 가지 형태로 손실을 가져오므로 망의 우회경로 설정 및 복구방안은 중요한 요소가 되고 있다. 망 복구에 있어서 중요한 과제는 작업 경로(working path)에 대한 복구 경로(restoration path)를 설정하는 것이다. 장애가 발생하더라도 서비스의 중단이 없도록 하기 위해서는 복구 경로를 설정할 때 작업 경로의 대역을 보장할 수 있는 복구 경로를 실정해야 한다. 이를 위해 MPLS망에서는 명시적 Routing기법에 기반을 둔 Constraint-based routing이 제안되었고 또한 망의 경로 복구를 위해 정적 및 동적설정기법이 제안되고 있다. 본 논문에서 제안된 방식은 확장된 OSPF 프로토콜의 TE-LSAs를 이용하여 또 다른 virtual 망을 구성하고 기본경로 중간의 TE-LSR을 새로운 PIL로 설정하여 빠른 대체 LSP를 설정 및 복구하는 기법을 성능 비교를 통해 망 자원의 효율적 사용을 보고자 한다.