Title
A comparison of router architectures for virtual cut-through and wormhole switching in a NOW environment
Abstract
Most multicomputer interconnection networks use wormhole switching, leading to fast and compact routers. Current routers incorporate virtual channels and even fully adaptive routing. Networks of workstations (NOWs) inherited multicomputer technology. Most commercial routers designed for NOWs implement wormhole switching. However, wormhole switching is not well suited for NOWs. The long wires required in this environment lead to large buffers to prevent buffer overflow during flow control signaling. Moreover, wire length is limited by buffer size. Virtual cut-through (VCT) achieves a higher throughput than wormhole switching. However, buffer requirements and packetizing overhead prevented its widespread use in multicomputers. Nevertheless, wormhole and VCT switching require similar buffer capacity in NOWs. Moreover, some messaging layers such as Illinois Fast Messages (FM) and BIP split messages into packets for increased performance. Therefore, the traditional disadvantages of VCT switching disappear in NOWs. In this paper, we show that VCT routers can be simpler than wormhole routers, while still achieving the advantages of using virtual channels and adaptive routing. We also propose a fully adaptive routing algorithm for VCT switching in a NOW environment. Moreover, we show that VCT routers outperform wormhole routers in a NOW environment at a lower cost. Also, VCT routers require buffer capacity independent of wire length, making them suitable for networks of workstations.
Year
DOI
Venue
2001
10.1006/jpdc.2000.1679
Journal of Parallel and Distributed Computing
Keywords
Field
DocType
virtual cut-through switching,irregular topologies,deadlock avoidance,router architecture,networks of workstations,adaptive routing,wormhole switching,virtual cut-through,flow control,throughput,packet switching,network routing,computer networks,pipelines,routing,computer worms,buffer overflow
Computer science,Wormhole switching,Communication channel,Computer network,Flow control (data),Packet switching,Router,Throughput,Wormhole,Buffer overflow
Journal
Volume
Issue
ISSN
61
2
Journal of Parallel and Distributed Computing
Citations 
PageRank 
References 
21
0.98
26
Authors
4
Name
Order
Citations
PageRank
J. Duato182974.13
A. Robles216813.94
F. Silla317316.36
R. Beivide445536.74