Given the need to provide users with reasonable feedback about the "costs" their network usage incurs and the increasingly commercial nature of the Internet, we believe that the allocation of cost among users will play an important role in future networks. This paper discusses cost allocation in the context of multicast flows. The question we discuss is this. When a single data flow is shared among many receivers, how does one split the cost of that flow among the receivers? Multicast routing increases network efficiency by using a single shared delivery tree. We address the issue of how these savings are allocated among the various members of the multicast group. We first consider an axiomatic approach to the problem, analyzing the implications of different distributive notions on the resulting allocations. We then consider a "one-pass" mechanism to implement such allocation schemes and investigate the family of allocation schemes such mechanisms can support.

Given the need to provide users with reasonable feedback about the "costs" their network usage incurs, and the increasingly commercial nature of the Internet, we believe that the allocation of cost among users will play an important role in future networks. This paper discusses cost allocation in the context of multicast flows. The question we discuss is this: when a single data flow is shared among many receivers, how does one split the cost of that flow among the receivers? Multicast routing increases network efficiency by using a single shared delivery tree. We address the issue of how these savings are allocated among the various members of the multicast group. We first consider an axiomatic approach to the problem, analyzing the implications of different distributive notions on the resulting allocations. We then consider a one-pass mechanism to implement such allocation schemes and investigate the family of allocation schemes such mechanisms can support.

Rule-Based Systems in the legal domain are often obtained by formalizing legislation. We consider the addition of meta-knowledge in the form of meta-rules to such a system. Such an approach has many advantages both for control and for dealing with the intrinsic vagueness of legal rules. Legal computer systems of different kinds have been proposed and built over the years. In this paper we shall present a legal reasoning system which uses concepts discussed in this paper. The system consists of a knowledge base, obtained by formalizing legislation, and uses a meta-rules mechanism for deduction and legal reasoning.