Implementation of DSR Protocol by Using Distributed Cache Update Algorithms

In contrast, on demand protocols attempt to discover a route only when a route is needed. To reduce the overhead and the latency of initiating a route discovery for each packet, on-demand routing protocols use route Caches. Due to mobility, cached routes easily become stale. Using stale routes causes packet losses, and increases latency and overhead. We investigate how to make on-demand routing protocols adapt quickly to topology changes. This problem is important because such protocols use route caches to make routing decisions; it is challenging because topology changes are frequent. ? We propose proactively disseminating the broken link information to the nodes that have that link in their caches. Proactive cache updating is key to making route caches adapt quickly to topology changes. It is also important to inform only the nodes that have cached a broken link to avoid unnecessary overhead. Thus, when a link failure is detected, our goal is to notify all reachable nodes that have cached the link about the link failure. We define a new cache structure called a cache table to maintain the information necessary for cache updates We design a distributed algorithm that uses the information kept by each node to achieve distributed cache updating. When a link failure is detected, the algorithm notifies selected neighborhood nodes about the broken link