A deadlock-free dynamic reconfiguration protocol for distributed routing on interconnection networks

In interconnection networks, reconfiguration protocol is necessary to remap and reconnect the network paths, so that the network remains connected. However, the reconfiguration process brings the deadlock problem and prevention of deadlock is a tedious task in this situation. In existing works, very little work have considered deadlock problem and further, they paid no attention to reduce packet loss rate. In this paper, we propose a Token-Based (TB) robust deadlock-free dynamic reconfiguration protocol. When a device observes topology changes or detects faulty nodes, it triggers the reconfiguration process and it becomes the Reconfiguration Controller (RC). Initially, HELLO message is transmitted by the RC to all devices for which they respond with a network status message. The RC constructs the new routing function based on the received network status messages. To synchronize the old and new routing functions, the RC distributes Reconfiguration Token (RT) in an ordered way. First, it distributes to the devices that surrounds the failed device and then to other devices. Every device holds the packet until it gets packet according to new routing function and then starts the transmission. By simulation, we show efficacy of our reconfiguration protocol. The network evaluation parameter like throughput, latency (delay) and pocket loss are measured in the high and low load scenarios in NS2 network simulator. We compare the results with existing protocol Overlapping Static Reconfiguration (OSR). Based on the simulation results we have proved that the proposed token based reconfiguration protocol is produces better efficiency in all aspects.