The Research And Implementation Of Concurrent Environment For Multiple Faults MPLS And IP Protection Switching Technology

With the development of information science and technology, especially the continuous development of computer technology, computer network technology was widely used now. All sectors of society are becoming increasingly dependent on computer network. Computer network has become the important infrastructure in our life.Providing a robust and efficient computer network has become a very important issue to our research work.At present, MPLS and IP technologies have been widely used in computer network. MPLS protection switching and IP fast reroute techniques are the most popular technologies for network survivability, but they are far from perfect and some deficiencies still exsist:For the MPLS protection switching:(1) In unidirectional fault detection method such as ITU-T's CV (Connectivity Verification), the export node discovers the LSP fault and controls entrance node for protection switching. That is to say, the entrance node can not find the LSP fault independently and protection switching on the entrance node must rely on export node.(2) The current protection switching technology can only deal with single LSP fault, which could not cope with concurrent LSP fault.For the IP fast reroute: In the IP fast rerouting technology, the network nodes calculate the backup link for the link which connected with themselves.When single link fault occurs in the network, the network node can quickly deal with the fault.In multi-link fault cases, the IP fast reroute technology may lead to routing loops.This paper carried out the following design, implementation and research work to solve the problems mentioned above:(1) Design and implementation of Spec Ping:This technology is a concrete implementation of unidirectional fault detection, which works like ICMP Ping, but Spec Ping have make up the deficiency that Ping works in the MPLS network.(2) Design and implementation of EMPS:This technology is based on an existing bidirectional fault detection technology and achieved the enhanced protection switching through recording the LSP states. This will compensate the inadequacies of current protection switching.(3) Research the main solutions of enhanced survival IP network:Analyze and compare the advantages and disadvantages of various solutions.(4) Analyze the phenomena of LFA (Loop Free Alternate) loop in multi-link failure:Analyze the reason of LFA solution for routing loops and design E-LFA (Enhanced Loop Free Alternate) to avoid routing loops.(5) Design and implementation of the E-LFA mechanism:Design and implement the E-LFA program based on the cognitive routing technology (CR), the E-LFA can automatic deployment and avoid routing loops.