Two issues in reservation establishment

This paper addresses two issues related to resource reservation establishment in packet switched networks offering real-time services. The first issue arises out of the natural tension between the local nature of reservations (i.e., they control the service provided on a particular link) and the end-to-end nature of application service requirements. How do reservation establishment protocols enable applications to receive their desired end-to-end service? We review the current one-pass and two-pass approaches, and then propose a new hybrid approach called one-pass-with-advertising. The second issue in reservation establishment we consider arises from the inevitable heterogeneity in network router capabilities. Some routers and subnets in the Internet will support real-time services and others, such as ethernets, will not. How can a reservation establishment mechanism enable applications to achieve the end-to-end service they desire in the face of this heterogeneity? We propose an approach involving replacement services and advertising to build end-to-end service out of heterogeneous per-link service offerings.