A study of AF and EF services interaction

Assured forwarding (AF) service allows the Internet service provider (ISP) to offer different levels of forwarding assurances to IP packets received from a customer. However, in a basic AF service-capable network, it is not possible to guarantee low latency and low jitter to IP packets. To support the transport of video/audio traffic with acceptable delay and jitter, the AF service is not sufficient. To rectify this, the Internet Engineering Task Force (IETF) has proposed the expedited forwarding (EF) service for the support of latency and jitter sensitive traffic. We examine the possibility of using AF service-capable networks to support the EF service. The implication of a positive answer to this question is that it will be possible to use AF service-capable networks to provide low delay and low delay jitter guarantees to video/audio-like traffic. We also analyze the impact of the EF service traffic on AF and best-effort traffic