Re: agenda for IPLDPN WG

[Ken-ichiro Murakami <[e-mail]>]

Dave,

>	I have been following the IP over circuit ISDN chat. The
>Japanese paper addressing multiple protocols seems to assume that on
>any one call only one protocol will exist. In the UK universities both
>TCP/IP communications and some uk 'coloured/rainbow/etcetc' networking
>exist. It is likely that I may want to call my site and
>simultaneously use both IP and another protocol interleaved on one
>ISDN circuit switched call. How should I handle this? Which
>documents offer guidelines??


I don't know UK colored book protocol suite in detail. But, I'll try
to answer your question. I guess UK Colored book runs over X.25 and
CR(Cambridge Ring). So, it might use X.75 LAPB and X.25 PLP over ISDN
Circuit Switching like T.90. Ordinarily, X.25 LAPB family including
X.75 LAPB does not use extended address field defined in ISO/IEC 3309.
So, it would be difficult to multiplex HDLC I-frame for UK colored
book and HDLC UI-frame for IP in the link layer over the same ISDN
circuit. But, there are some alternatives to run both protocols. They
are IP-over-X.25 and ISO-transport-service-over-TCP.

In terms of CL(connection-less) network protocols, MLP-over-ISDN
provides LINK protocol multiplexing. Some of link protocols such as
PPP and SCP-over-ISDN provides NETWORK protocol multiplexing. Thus,
you can utilize any CL protocol if you use a link protocol which
supports network protocol multiplexing. However, if you require
co-existence of CO(Connection Oriented) Protocol suite like UK colored
book and CL like IP, you have to utilize a X.25 virtual circuit as a
link for IP or utilize a TCP virtual circuit as an OSI virtual
circuit. As for multiplexing, RFC1331(PPP) and RFC1294(Frame Relay)
describes the scheme in detail. As for IP-over-X.25, please refer
draft-ietf-iplpdn-x25_isdn-03.txt. As for ISO-Transport-service-over
-TCP, RFC1006 explains the interface.

-Ken

Ken Murakami
NTT Laboratories
Tokyo, Japan