RFC 1307 (rfc1307) - Page 2 of 13
Dynamically Switched Link Control Protocol
Alternative Format: Original Text Document
RFC 1307 Dynamically Switched Link Control Protocol March 1992
1.1 Motivation
Circuit Switched Networks are becoming available to the Internet
community. These networks are made available by requesting a
connection through a switch. Normally circuit switched network links
are disconnected, and their prohibitive cost suggests that it is very
costly to leave them connected at all times.
Internet users and hosts wish to send data over a circuit switched
networks, but only connect the network links when a transport
connection is to be established. While it would be possible to use
packet routers to identify the need for switching a connection on and
off, only the transport provider can positively identify the
beginning and end of a transport session. There must be a mechanism
to activate and deactivate the link at the beginning and end of a
transport session.
The DSLCP assumes that a transport provider has knowledge of a
downstream link which must be setup before data transfer may take
place. However, the details of link setup may vary by the type of
link (circuit-switched or other), specific hardware, or
administrative differences. The DSLCP hides these details from the
transport provider by offering a simple request/release model of link
preparation. The model assumes an entity in control of the link
which handles the details of connection preparation while responding
to the DSLCP commands of the transport provider. This entity is
called the link controller.
The DSLCP allows internet hosts to dynamically change the fabric of
the internet by sending messages through the internet in advance of
data which is to travel across the newly created links.
1.2 Scope
DSLCP is intended to provide an interface between transport providers
and arbitrary network links requiring creation, control, setup, or
conditioning before data communications may take place.
1.3 Interfaces
There are no specific user level interfaces to DSLCP, although they
are not precluded. Link control is a function of the network layer,
initiated by requests from the transport provider.
A DSLCP transaction is defined as a transport provider communicating
with a link controller for the duration of transport session. A
network path between the host providing transport services and the
link controller must exist in advance of the DSLCP transaction.
Young & Nicholson