Browse Prior Art Database

Echo function for ISO 8473 (RFC1139)

IP.com Disclosure Number: IPCOM000001950D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 6 page(s) / 13K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R.A. Hagens: AUTHOR

Abstract

This memo defines an echo function for the connection-less network layer protocol. Two mechanisms are introduced that may be used to implement the echo function. The first mechanism is recommended as an interim solution for the Internet community. The second mechanism will be progressed to the ANSI X3S3.3 working group for consideration as a work item.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 23% of the total text.

Network Working Group IETF-OSI Working Group

Request for Comments: 1139 R. Hagens

January 1990

An Echo Function for ISO 8473

Status of this Memo

This memo defines an echo function for the connection-less network

layer protocol. This memo is not intended to compete with an ISO

standard. This is a Proposed Elective Standard for the Internet.

Distribution of this memo is unlimited.

Abstract

This memo defines an echo function for the connection-less network

layer protocol. Two mechanisms are introduced that may be used to

implement the echo function. The first mechanism is recommended as

an interim solution for the Internet community. The second mechanism

will be progressed to the ANSI X3S3.3 working group for consideration

as a work item.

When an ISO standard is adopted that provides functionality similar

to that described by this memo, then this memo will become obsolete

and superceded by the ISO standard.

1. Introduction

The OSI Connection-less network layer protocol (ISO 8473) defines a

means for transmitting and relaying data and error report PDUs

through an OSI internet. Unfortunately, the world that these packets

travel through is imperfect. Gateways and links may fail. This memo

defines an echo function to be used in the debugging and testing of

the OSI network layer.

Network management protocols can be used to determine the state of a

gateway or link. However, since these protocols themselves utilize a

protocol that may experience packet loss, it cannot be guaranteed

that the network management applications can be utilized. A simple

mechanism in the network layer is required so that systems can be

probed to determine if the lowest levels of the networking software

are operating correctly. This mechanism is not intended to compete

with or replace network management; rather it should be viewed as an

addition to the facilities offered by network management.

There are three important issues to consider when defining an echo

extension to ISO 8473: complexity, code-path divergence, and backward

compatibility. The complexity of the echo facility must be kept low.

If it is not, then there is a good chance that the facility will not

be universally provided. The code-path consideration requires that

the echo path through a system is identical (or very close) to the

path used by normal data. An echo path must succeed and fail in

unison with the normal data path or else it will not provide a useful

diagnostic tool.

Backward compatibility is an important consideration whenever a

change is made to a protocol. For this reason, this memo defines two

implementation mechanisms: the short term approach and the long term

approach. The short term approach will produce echo packets that are

indistinguishable from normal data IS...