A new Request for Comments is now available in online RFC libraries.


        RFC 1793:

        Title:      Extending OSPF to Support Demand Circuits
        Author:     J. Moy
        Date:       April 1995
        Mailbox:    jmoy@casc.com
        Pages:      31
        Characters: 78,728
        Updates/Obsoletes:  none

        URL:        ftp://ds.internic.net/rfc/rfc1793.txt


This memo defines enhancements to the OSPF protocol that allow
efficient operation over "demand circuits".  Demand circuits are
network segments whose costs vary with usage; charges can be based
both on connect time and on bytes/packets transmitted.  Examples of
demand circuits include ISDN circuits, X.25 SVCs, and dial-up lines.
The periodic nature of OSPF routing traffic has until now required a
demand circuit's underlying data-link connection to be constantly
open, resulting in unwanted usage charges.  With the modifications
described herein, OSPF Hellos and the refresh of OSPF routing
information are suppressed on demand circuits, allowing the underlying
data-link connections to be closed when not carrying application
traffic.  This RFC is a product of the Open Shortest Path First IGP
Working Group of the IETF.

This is now a Proposed Standard Protocol.

This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements.  Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state and
status of this protocol.  Distribution of this memo is unlimited.

This announcement is sent to the IETF list and the RFC-DIST list.
Requests to be added to or deleted from the IETF distribution list
should be sent to IETF-REQUEST@CNRI.RESTON.VA.US.  Requests to be
added to or deleted from the RFC-DIST distribution list should
be sent to RFC-REQUEST@NIC.DDN.MIL.

Details on obtaining RFCs via FTP or EMAIL may be obtained by sending
an EMAIL message to rfc-info@ISI.EDU with the message body 
help: ways_to_get_rfcs.  For example:

        To: rfc-info@ISI.EDU
        Subject: getting rfcs

        help: ways_to_get_rfcs

Requests for special distribution should be addressed to either the
author of the RFC in question, or to admin@DS.INTERNIC.NET.  Unless
specifically noted otherwise on the RFC itself, all RFCs are for
unlimited distribution.

Submissions for Requests for Comments should be sent to
RFC-EDITOR@ISI.EDU.  Please consult RFC 1543, Instructions to RFC
Authors, for further information.


Joyce K. Reynolds
USC/Information Sciences Institute