Browse Prior Art Database

Routing between the NSFNET and the DDN (RFC1133) Disclosure Number: IPCOM000001944D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 8 page(s) / 21K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J.Y. Yu: AUTHOR [+2]


Status of this Memo

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 14% of the total text.

Network Working Group J. Yu

Request for Comments: 1133 H-W. Braun

Merit Computer Network

November 1989

Routing between the NSFNET and the DDN

Status of this Memo

This document is a case study of the implementation of routing

between the NSFNET and the DDN components (the MILNET and the

ARPANET). We hope that it can be used to expand towards

interconnection of other Administrative Domains. We would welcome

discussion and suggestions about the methods employed for the

interconnections. No standards are specified in this memo.

Distribution of this memo is unlimited.

1. Definitions for this document

The NSFNET is the backbone network of the National Science

Foundation's computer network infrastructure. It interconnects

multiple autonomously administered mid-level networks, which in turn

connect autonomously administered networks of campuses and research

centers. The NSFNET connects to multiple peer networks consisting of

national network infrastructures of other federal agencies. One of

these peer networks is the Defense Data Network (DDN) which, for the

sake of this discussion, should be viewed as the combination of the

DoD's MILNET and ARPANET component networks, both of which are

national in scope.

It should be pointed out that network announcements in one direction

result in traffic the other direction, e.g., a network announcement

via a specific interconnection between the NSFNET to the DDN results

in packet traffic via the same interconnection between the DDN to the


2. NSFNET/DDN routing until mid '89

Until mid-1989, the NSFNET and the DDN were connected via a few

intermediate routers which in turn were connected to the ARPANET.

These routers exchanged network reachability information via the

Exterior Gateway Protocol (EGP) with the NSFNET nodes as well as with

the DDN Mailbridges. In the context of network routing these

Mailbridges can be viewed as route servers, which exchange external

network reachability information via EGP while using a proprietary

protocol to exchange routing information among themselves.

Currently, there are three Mailbridges at east coast locations and

three Mailbridges at west coast locations. Besides functioning as

route servers the Mailbridges also provide for connectivity, i.e,

packet switching, between the ARPANET and the MILNET.

The intermediate systems between the NSFNET and the ARPANET were

under separate administrative control, typically by a NSFNET mid-

level network.

For a period of time, the traffic between the NSFNET and the DDN was

carried by three ARPANET gateways. These ARPANET gateways were under

the administrative control of a NSFNET mid-level network or local

site and had direct connections to both a NSFNET NSS and...