RFC 1787 (rfc1787) - Page 1 of 8
Routing in a Multi-provider Internet
Alternative Format: Original Text Document
Network Working Group Y. Rekhter
Request for Comments: 1787 T.J. Watson Research Center, IBM Corp.
Category: Informational April 1995
Routing in a Multi-provider Internet
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
This document was prepared by the author on behalf of the Internet
Architecture Board (IAB). It is offered by the IAB to stimulate
discussion.
Over the past few years the Internet has undergone significant
changes. Among them is the emergence of multiple Network Service
Providers, where resources that provide Internet-wide IP connectivity
(routers, links) are controlled by different organizations. This
document presents some of the issues related to network layer routing
in a multi-provider Internet, and specifically to the unicast
routing.
1. Network Service Providers vs Network Service Subscribers
Within the current routing paradigm the service offered by a provider
at the network layer (IP) is the set of destinations (hosts) that can
be reached through the provider. Once a subscriber establishes direct
connectivity to a provider, the subscriber can in principle reach all
the destinations reachable through the provider. Since the value of
the Internet-wide connectivity service offered by a provider
increases with the number of destinations reachable through the
provider, providers are motivated to interconnect with each other.
In principle a provider need not offer the same service (in terms of
the set of destinations) to all of its subscribers -- for some of the
subscribers the provider may restrict the services to a subset of the
destinations reachable through the provider. In fact, for certain
types of subscribers constrained connectivity could be seen as part
of the service offered by a provider.
In a multi-provider environment individual providers may be driven by
diverse and sometimes even conflicting goals and objectives. Some of
the providers exist to provide connectivity to only a specific group
Rekhter