Design and implementation of a diffserv enabled HFC system offering Strict QoS support

Widespread deployment of Hybrid Fiber Coaxial (HFC) systems created a new residential access platform upgrading traditional cable TV networks, which were limited to distributed services. This evolution is driven by demand for faster Internet access from customers frustrated by slow telephone line and ISDN modem speeds. As residential traffic with voice and video‐intensive content proliferates, the current generation of cable modems, which are oriented towards best‐effort traffic, will need to be enhanced with new capabilities to handle the increased bandwidth and quality requirements. To integrate telecom services presenting diverse quality requirements over the same HFC access infrastructure necessitates a degree of isolation of traffic classes. The difficulty of handling finer aggregations because of the limited MAC reservation resources and the cost limitation of residential access make the scalability of the differentiated services architecture as relevant in the HFC access network as in any traffic multiplexer. An implementation integrating IP and ATM and aligning the system to the DiffServ philosophy is presented in this paper. It constitutes an affordable system solution for residential customers enabling the support of QoS‐demanding services.