RFC 1193 (rfc1193) - Page 1 of 24
Client requirements for real-time communication services
Alternative Format: Original Text Document
Network Working Group D. Ferrari
Request for Comments: 1193 UC Berkeley
November 1990
CLIENT REQUIREMENTS FOR REAL-TIME COMMUNICATION SERVICES
Status of this Memo
This memo describes client requirements for real-time communication
services. This memo provides information for the Internet community,
and requests discussion and suggestions for improvements. It does
not specify any standard. Distribution of this memo is unlimited.
Abstract
A real-time communication service provides its clients with the
ability to specify their performance requirements and to obtain
guarantees about the satisfaction of those requirements. In this
paper, we propose a set of performance specifications that seem
appropriate for such services; they include various types of delay
bounds, throughput bounds, and reliability bounds. We also describe
other requirements and desirable properties from a client's
viewpoint, and the ways in which each requirement is to be translated
to make it suitable for lower levels in the protocol hierarchy.
Finally, we present some examples of requirements specification, and
discuss some of the possible objections to our approach.
This research has been supported in part by AT&T Bell Laboratories,
the University of California under a MICRO grant, and the
International Computer Science Institute. The views and conclusions
in this document are those of the author and should not be
interpreted as representing official policies, either expressed or
implied, of any of the sponsoring organizations.
1. Introduction
We call real-time a computer communication service whose clients are
allowed to specify their performance requirements and to obtain
guarantees about the fulfillment of those requirements.
Three terms in this definition need further discussion and
clarification: clients, performance, and guarantees.
Network architecture usually consists, at least from a logical
viewpoint, of a stack of protocol layers. In the context of such an
architecture, the notions of client and server apply to a number of
Ferrari