Integrated Services Mappings for Low Speed Networks (RFC2688)

Network Working Group S. Jackowski Request for Comments: 2688 Deterministic Networks Category: Standards Track D. Putzolu Intel Architecture Labs E. Crawley Argon Networks B. Davie Cisco Systems September 1999

Integrated Services Mappings for Low Speed Networks

Status of this Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

Abstract

A set of companion documents describe an architecture for providing integrated services over low-bitrate links, such as modem lines, ISDN B-channels, and sub-T1 links [1, 2, 3, 4]. The main components of the architecture are: a set of real-time encapsulation formats for asynchronous and synchronous low-bitrate links, a header compression architecture optimized for real-time flows, elements of negotiation protocols used between routers (or between hosts and routers), and announcement protocols used by applications to allow this negotiation to take place.

This document defines the service mappings of the IETF Integrated Services for low-bitrate links, specifically the controlled load [5] and guaranteed [6] services. The approach takes the form of a set of guidelines and considerations for implementing these services, along with evaluation criteria for elements providing these services.

Jackowski, et al. Standards Track [Page 1]

RFC 2688 Integrated Services Mappings Low Speed Nets September 1999

1. Introduction

In addition to the "best-effort" services the Internet is well-known for, other types of services ("integrated services") are being developed and deployed in the Internet. These services support special handling of traffic based on bandwidth, latency, and other requirements that cannot usually be met using "best-effort" service.

This document defines the mapping of integrated services "controlled load" [5] and "guaranteed" [6] services on to low-bandwidth links. The architecture and mechanisms used to implement these services on such links are defined in a set of companion documents. The mechanisms defined in these documents include both compression of flows (for bandwidth savings) [4,10] and a set of extensions to the PPP protocol which permit fragmentation [2] or suspension [3] of large packets in favor of packets from flows with more stringent service requirements.

1.1. Specification Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [11].

2. Issues for Providing Controlled and Guaranteed Service

Unlike other link layers, the links referred to in this document operate only over low speed point...