Naming and Directory Issues in Message Transfer Systems

Abstract

A message transfer system requires some means for users to determine the addresses of their correspondents. A Directory Service aids users in identifying a particular correspondent and the correspondent's address. In this paper we discuss the technical, economic, organizational and political requirements which must be satisified by a directory service. We develop a language for describing alternative architectures for directory service borrowed from notions of hierarchical computer file system design. We propose a system of naming and directory services which meets the stated requirements based on names which specify a path through a sequence of directories. Finally, we compare our proposal to several alternative designs for directory service which have appeared in the literature.