Producing a high hit ratio and low search time in forwarding routing tables by predicting IP addresses

Abstract

In computer networks, fast routing is one of the main factors to speed up the transmission of the IP packets from the source to the destination computers. A router has a forwarding table (cache table) and a routing table. The forwarding table is derived from the routing table, which is maintained constantly by the router using one of the common routing protocols. There are two factors that affect the speed of the forwarding decisions. First, when a forwarding table holds a huge number of IP addresses, a complicated search algorithm is needed, which implies a high search time. If a complicated search algorithm is not used, then the forwarding table has to be set up in a manner to reduce search time; this implies that the table must be set up by a processor that has a substantial computing power. Second, the availability of the incoming IP address in the forwarding table (hit rate) reduces the extended search in the routing table. Our study examines the IP address streams. Two models were built to predict IP addresses. These models are plugged into the cache system simulation to prefetch the IP addresses prior to the router requests. The prediction scheme produces a higher hit ratio in comparison with the current cache schemes. Also, it reduces the cache table size, which implies low search time.