Two Issues in Reservation Establishment

摘要

This paper addresses two issues related to resource reservation establishment in packet switched networks offering realtime 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 realtime 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.