The Integrated Services (Intserv) architecture provides a means for the delivery of end-to-end Quality of Service (QoS) to applications over heterogeneous networks. To support this end-to-end model, the Intserv architecture must be supported over a wide variety of different types of network elements. In this context, a network that supports Differentiated Services (Diffserv) may be viewed as a network element in the total end-to-end path. This document describes a framework by which Integrated Services may be supported over Diffserv networks.

One of the key issues in deployment of QoS is determining the set of applications or users, which are allowed to have a preferential access to network resources. The administrative criteria for regulating access to resources constitute the QoS policies. A policy could determine which of the reservation requests in the network be honored during the processing of a signaling protocol such as RSVP, or it could determine the class of applications or users which are to be placed in a specific DiffServ class of service. In this paper, we look at the issues that arise in the definition, deployment and management of policies related to QoS in an IP network. The paper provides an overview of the requirements for QoS policies, the alternate policy architectures that can be deployed in a network, the different protocols that can be used to exchange policy information, and the exchange of policy information among different administrative domains. We provide a coverage of the current issues being examined in IETF and other standard bodies, as well as issues explored in policy related research ongoing at different universities and research labs.

Abstract-We propose a framework for the creation and maintenance of multicast trees in hierarchical ATM networks. This framework aims at coping with an inherent difficulty of topology aggregating in such networks. The main idea of the proposed framework is to distribute the tree topology information among a set of hierarchical Multicast Group Servers (MGSs) nominated for each multicast tree, while keeping regions that do not have a member in the multicast group unaware of the tree. The framework can be employed with every multicast routing algorithm designed for non-hierarchical networks.

ATM PNNI (Private Network-to-Network Interface) is a hierarchical and dynamic link-state routing protocol, designed to scale to the largest possible ATM networks, encompassing thousands of nodes. The paper investigates the route computation load imposed by the PNNI routing scheme, and shows that this load is unevenly distributed among the network nodes. More specifically, the routing computation load associated with the set up of a single VC grows exponentially with the hierarchy level. As a result, some of the network nodes -mainly those that function as border nodes of high levels -may be overloaded with route computation, while other nodes are rarely involved in this process. The paper also proposes a possible scheme for spreading the route computation burden more evenly. According to this scheme, heavily loaded nodes transfer route computation tasks to lightly loaded nodes. 0

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