Provision of deterministic services for voice over IP using priority queues

This paper discusses an approach for resource allocation and management in IP networks, particularly in the context of IP telephony. We show that it is possible to provide deterministic real time services without substantial changes to the current Internet infrastructure using static priority scheduling. All IP telephony traffic is mapped to (unidirectional) virtual channels that allow simple aggregation schemes and subdivision in two parts. We present a calculus to compute the effective bandwidth needed to serve each packet in a service specific time for static priority schedulers. The calculus has been reviewed by simulations. It is used for access control purposes and has the benefit that it can be applied to each node of a network not depending on the other nodes. The virtual channels can logically be subdivided in two parts. Thus, signaling does not need to run from one end to the other, but from both ends simultaneously to the point of aggregation in between. It is shown that the approach can fulfill the requirements of a network build from campus networks connected via a backbone network.