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Specification of the Controlled-Load Network Element Service (RFC2211)

IP.com Disclosure Number: IPCOM000002769D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 16 page(s) / 43K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Wroclawski: AUTHOR

Abstract

This memo specifies the network element behavior required to deliver Controlled-Load service in the Internet. Controlled-load service provides the client data flow with a quality of service closely approximating the QoS that same flow would receive from an unloaded network element, but uses capacity (admission) control to assure that this service is received even when the network element is overloaded.

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This is the abbreviated version, containing approximately 7% of the total text.

Network Working Group J. Wroclawski

Request For Comments: 2211 MIT LCS

Category: Standards Track September 1997

Specification of the Controlled-Load Network Element Service

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.

Abstract

This memo specifies the network element behavior required to deliver

Controlled-Load service in the Internet. Controlled-load service

provides the client data flow with a quality of service closely

approximating the QoS that same flow would receive from an unloaded

network element, but uses capacity (admission) control to assure that

this service is received even when the network element is overloaded.

1. Introduction

This document defines the requirements for network elements that

support the Controlled-Load service. This memo is one of a series of

documents that specify the network element behavior required to

support various qualities of service in IP internetworks. Services

described in these documents are useful both in the global Internet

and private IP networks.

This document is based on the service specification template given in

[1]. Please refer to that document for definitions and additional

information about the specification of qualities of service within

the IP protocol family.

2. End-to-End Behavior

The end-to-end behavior provided to an application by a series of

network elements providing controlled-load service tightly

approximates the behavior visible to applications receiving best-

effort service *under unloaded conditions* from the same series of

network elements. Assuming the network is functioning correctly,

these applications may assume that:

- A very high percentage of transmitted packets will be

successfully delivered by the network to the receiving end-nodes.

(The percentage of packets not successfully delivered must closely

approximate the basic packet error rate of the transmission

medium).

- The transit delay experienced by a very high percentage of the

delivered packets will not greatly exceed the minimum transmit

delay experienced by any successfully delivered packet. (This

minimum transit delay includes speed-of-light delay plus the fixed

processing time in routers and other communications devices along

the path.)

To ensure that these conditions are met, clients requesting

controlled-load service provide the intermediate network elements

with a estimation of the data traffic they will generate; the TSpec.

In return, the service ensures that network element resources

adeq...