Sharad Sundaresan Riccardo Bettati
Department of Computer Science
H.R. Bright Building
Texas A&M University
College Station, TX 77843-3112
tel: (409) 845-5469
fax: (409) 847-8578
{sharad,bettati}@cs.tamu.edu
Wormhole networks provide a very-high-speed communication medium that is well suited for a large number of bandwidth demanding applications. Unfortunately, the lack of buffering in the switches causes blocked packets to transiently monopolize arbitrary large portions of the network, thus making it difficult to give real-time guarantees when connections contend for communication links. We present an efficient, fully distributed admission control scheme for time-critical connections over wormhole networks. Such a distributed scheme offers advantages in terms of scalability and easy integration into hybrid networks, over a corresponding centralized scheme. We also developed a CAC protocol which implements this distributed scheme over a testbed network. We compare this scheme to a centralized algorithm in a suite of simulation experiments and show that its performance is encouraging.