An assessment of state and lookup overhead in routers

The current internet is based on a stateless (datagram) architecture. However, many recent proposals rely on the maintenance of state information within network routers, leading to the authors´ interest in the implications of a stateful network layer. They collected internetwork traffic traces at the border routers of stub and transit networks, and used these data to evaluate, or predict, the effects of design alternatives for stateful architectures. They present an estimate of the number of active conversations at a router, and from this derive the storage requirements for the associated conversation state table. The analysis shows that, at the network periphery, fine-grain control over the traffic may be possible. However, deeper within the network, it may be more efficient to manage the conversations at a coarser level. The network traffic traces are used to perform trace driven simulations of an LRU cache, for different conversation granularities. Results show that locality exists for each of the conversation types investigated