03-12-2012, 01:56 PM
DISTRIBUTED CACHE UPDATING USING DYNAMIC SOURCE ROUTING PROTOCOL
ABSTRACT
The purpose of our project is to proactively disseminating the broken link information to the
nodes that have link in their caches. We define a new cache structure called a cache table and
present a distributed cache update algorithm. Each node maintains in its cache table the
information necessary for cache updates.
Existing System
• TCP performance degrades significantly in Mobile Ad hoc Networks due to the packet losses.
Most of these packet losses result from the Route failures due to network mobility.
• TCP assumes such losses occur because of congestion, thus invokes congestion control
mechanisms such as decreasing congestion windows, raising timeout, etc, thus greatly
reduce TCP throughput.
• However, after a link failure is detected, several packets will be dropped from the network
interface queue; TCP will time out because of these packet losses, as well as for
Acknowledgement losses caused by route failures.
• There is no intimation information regarding the failure links to the node from its
neighboring Node’s. So that the Source Node cannot able to make the Route Decision’s at
the time of data transfer.
Proposed System
• Prior work in Dynamic Source Routing Protocol used heuristics with ad hoc parameters to
predict the lifetime of a link or a route. However, heuristics cannot accurately estimate
timeouts because topology changes are unpredictable.
• Prior researches have proposed to provide link failure feedback to TCP, so that TCP can avoid
responding to route failures as if congestion had occurred.
• We propose proactively disseminating the broken link information to the nodes that have
that link in their caches. We define a new cache structure called a cache table and present a
distributed cache update algorithm. Each node maintains in its cache table the Information
necessary for cache updates.