Dynamically Switched Link Control Protocol (RFC1307)
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
J. Young: AUTHOR [+2]
This memo describes an experimental protocol developed by a project team at Cray Research, Inc., in implementing support for circuit- switched T3 services. The protocol is used for the control of network connections external to a host, but known to the host. It is documented here for the benefit of others who may wish to perform further research.
Network Working Group J. Young
Request for Comments: 1307 A. Nicholson
Cray Research, Inc.
Dynamically Switched Link Control Protocol
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. Discussion and suggestions for improvement are requested.
Please refer to the current edition of the "IAB Official Protocol
Standards" for the standardization state and status of this protocol.
Distribution of this memo is unlimited.
This memo describes an experimental protocol developed by a project
team at Cray Research, Inc., in implementing support for circuit-
switched T3 services. The protocol is used for the control of
network connections external to a host, but known to the host. It is
documented here for the benefit of others who may wish to perform
While working with circuit-switched T3 networks, developers at Cray
Research, Inc., defined a model wherein a host would generate control
messages for a network switch. This work is described in RFC 1306,
"Experiences Supporting By-Request Circuit-Switched T3 Networks". In
order to simplify the model it was decided that the inconsistencies
of switch control should be hidden from the host generating the
control messages. To that end, a protocol was defined and
implemented. This RFC documents the Dynamically Switched Link
Control Protocol (DSLCP), which is used for creation and control of
downstream network links by a host.
The Dynamically Switched Link Control Protocol (DSLCP) allows a host
with knowledge of a special downstream network link to issue messages
to control the status of that link.
This document describes the functions of the DSLCP to control
external network connections.
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
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 o...