Adpative Network Protocol Tuning with On-line Simulation

Many existing network protocols need to be adaptively configured for the prevailing network conditions. This paper presents a scalable and flexible network protocol configuration tool, the on-line simulation scheme. The optimal configuration of network protocols can be formulated as a black-box optimization problem where the network is considered as a black-box and its performance can be evaluated with network simulations. The on-line simulation scheme provides a systematic way to perform adaptive protocol configuration with the black-box optimization approach. It basically monitors network conditions and employs an efficent search algorithm to optimize the network protocol configuration whenever significant changes in network conditions occur. The on-line simulation scheme does not require modifying existing network protocols in any way, instead it applies a second order control by tuning the parameters of network protocols. This scheme is very flexible in that various performance objectives, such as, maximum throughput or minimum packet loss, can be achieved by using a proper performance metric in optimization. In addition, it is very easy to be applied to any network protocol as long as the protocol is sensitive to its parameter setting. The on-line simulation scheme has been successfully applied to the tuning of some network protocols, such as, RED queueing algorithm, OSPF and BGP routing protocols. The simulation results of these applications are also presented in this paper.