Diffserv’s Assured Forwarding PHB: What Assurance does the Customer Have?

ABSTRACT: This paper examines issues related to as-suring the performance parameters of a Service Level Agreement in an Assured Forwarding based Diffserv-capable IP network. In an effort to understand the kinds of quantifiable parameters that can be included in a con-tract, the results of detailed studies on one such parameter (throughput) are presented. Based on simulation and pro-totype-implementations at least seven different factors are studied which can bias bandwidth assurance for equal paying customers. Design options for Intelligent Traffic Conditioning schemes at the edge of the network to miti-gate the effect of these factors are discussed. The scope of network for which such schemes are viable is assessed. There are open issues that need to be addressed before such schemes can achieve their desired effect on the gen