Quality of service (QoS) routing algorithms have become the focus of recent research due to their potential for increasing the utilization of an integrated services packet network (ISPN) that handles requests with QoS requirements. While heuristics for determining paths for such requests have been formulated for a variety of QoS models, little attention has been given to the overall processing complexity of the QoS routing architecture. Although on demand path computation is very attractive due to its simplicity, many believe that its processing cost will be prohibitive in environments with high request rates. In this work, we first characterize the processing cost of QoS routing algorithms that use the constrained widest-shortest path heuristic to compute QoS paths in a link state based routing environment. By simulating a variety of realistic traffic conditions we investigate the effectiveness of path pre-computation in reducing the amount of routing protocol computation. We mainly want to determine how much reduction in routing processing cost is possible before the routing performance becomes unacceptably low. Our results show that path pre-computation can significantly reduce the processing cost of on-demand path computation but with a proportional routing performance loss.
[1]
Ariel Orda,et al.
QoS Routing Mechanisms and OSPF Extensions
,
1999,
RFC.
[2]
Jon Crowcroft,et al.
Quality-of-Service Routing for Supporting Multimedia Applications
,
1996,
IEEE J. Sel. Areas Commun..
[3]
A. Udaya Shankar,et al.
Design and implementation of MaRS: a routing testbed
,
1992
.
[4]
Peter Steenkiste,et al.
On path selection for traffic with bandwidth guarantees
,
1997,
Proceedings 1997 International Conference on Network Protocols.
[5]
Pierre A. Humblet,et al.
Routing subject to quality of service constraints in integrated communication networks
,
1995,
IEEE Netw..