Congestion detection in Ant Based Survivable Routing and Wavelength Allocation in WDM Networks Rangaswamy M.*, Rajesh P.**, Prasanthi M. S.*** Dept. of ECE, JNTUA College of Engineering, Pulivendula *ranga3817@gmail.com
**raj06453@gmail.com
***ms.prasanthi456@gmail.com
Online published on 27 June, 2017. Abstract Initially, in the path, a major part of the band-width is allocated for primary path and this part cannot be shared by other paths. Fraction of the bandwidth is allocated for backup path and this can be shared by other disjoint paths. The disjoint path can be primary or backup path. The residual bandwidth is used for future primary and backup paths computations. When the connection request arrives to the source, it looks in its pheromone and load table and send connection request (CNREQ) message to the destination along with feasibility and load values of paths. Upon receiving the CNREQ, the path that has higher feasibility value and the load value lesser than ThLOAD can be selected by the destination for further processing. The backup path can be triggered in two scenarios. (i) Failure Detection (ii) Congestion Detection When any intermediate node detects node failure or fiber failure, then it sends FAILURE warning message to the source node along the alternate light path. To detect congestion, the value of path load should not exceed the ThLOAD. If the load value exceeds beyond ThLOAD, then it will lead the network to congestion and consequently to the blocking of services. Thus, to prevent these, we let the intermediate node to send a CONGESTION warning message to the source before it exceeds ThLOAD. If the source node receives either FAIL-URE or CONGESTION warning message from the intermediate nodes, it triggers the backup path protection and establishes back up light path from the estimated set of light paths (from the ant agents). The source node looks its pheromone and load table and select the path that has low load value and higher feasibility value as next hop and precedes the transmission. During the transmission, if the load value exceeds the ThLOAD, then backup path can be triggered by the corresponding node Top Keywords Backup paths, Survivable routing, Static paths, Primary path, Congestion, Feasibility. Top |