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From: munnari!cit5.cit.oz.au!jwb@uunet.uu.net (Jim Breen)
Newsgroups: comp.dcom.telecom
Subject: Re: TCP/IP over ISDN Basic Rate
Message-ID: <telecom-v09i0474m11@vector.dallas.tx.us>
Date: 25 Oct 89 01:06:59 GMT
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X-TELECOM-Digest: volume 9, issue 474, message 11 of 11

gnu@toad.com asks, of ISDN
>   The problem is data encoding; I
> have seen no documentation of standard ways to encode data passing on
> the 8000 byte/sec channel for IP.  I have seen references to ways of
> encoding e.g. 9600 baud async "RS232" traffic over ISDN, but I will be
> talking ISDN-to-ISDN, so can use the full bandwidth.  Rumor has it
> that somebody had standardized bit-oriented protocols (HDLC) over ISDN
> links, which is ridiculous since they are byte oriented links.......

They are NOT byte-oriented 8000 byte/sec; it is BIT oriented 64000
bps. You can put any protocol you like on an ISDN B-channel. Protocols
have been standardized for the D-channel, as this is for signalling
and packet traffic.

There *are* ISDN standards for mapping lower speeds onto a B-channel.
Check out standards I.460-464 from the CCITT Red Book for starters.

> Can anyone on Telecom provide details on upper level ISDN
> standardization efforts?  All I have found was low level protocols;
> once you get to the 8000 bps byte stream, it's left up to the user to
> define........

This is how it should be! There are standards for various things to
intercommunicate over ISDN, such as Group 4 Fax, etc., buter there
must NEVER be a standard protocol above Layer 1. ISDN is to be a
bit-pipe service.

        _______           Jim Breen (jwb@cit5.cit.oz) Department of Robotics &
       /o\----\\     \O      Digital Technology. Chisholm Inst. of Technology
      /RDT\   /|\   \/|   -:O____/         PO Box 197 Caulfield East 3145
     O-----O        _/_\    /\ /\          (p) 03-573 2552 (fax) 572 1298