From owner-freebsd-isdn Wed Jan 20 00:43:15 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA25932 for freebsd-isdn-outgoing; Wed, 20 Jan 1999 00:43:15 -0800 (PST) (envelope-from owner-freebsd-isdn@FreeBSD.ORG) Received: from hcsext.hcs.de (hcsext.hcs.de [194.123.40.2]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id AAA25925 for ; Wed, 20 Jan 1999 00:43:12 -0800 (PST) (envelope-from hm@hcs.de) Received: from hcswork.hcs.de([192.76.124.5]) (2535 bytes) by hcsext.hcs.de via sendmail with P:smtp/R:inet_hosts/T:smtp (sender: ) id for ; Wed, 20 Jan 1999 09:43:05 +0100 (CET) (Smail-3.2.0.104 1998-Nov-20 #1 built 1998-Dec-11) Received: by hcswork.hcs.de (Smail3.1.29.0 #12) id m102tE8-0000fUC; Wed, 20 Jan 99 09:43 MET Message-Id: From: hm@hcs.de (Hellmuth Michaelis) Subject: Re: D-channel communications In-Reply-To: <36A4FD37.443DABAE@scc.nl> from Marcel Moolenaar at "Jan 19, 99 10:46:31 pm" To: marcel@scc.nl (Marcel Moolenaar) Date: Wed, 20 Jan 1999 09:43:04 +0100 (MET) Cc: isdn@FreeBSD.ORG Reply-To: hm@hcs.de Organization: HCS Hanseatischer Computerservice GmbH X-Mailer: ELM [version 2.4ME+ PL39 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isdn@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >From the keyboard of Marcel Moolenaar: > Are there any plans to implement communications over the D-channel? No. > Are people interested in such an implementation? I'm not interested, but it would be an interesting project ;-) Anyway: which sort of communications ? If its just communications, we are already doing that :-) Basically i can think of 3 sorts of communications over the D-channel: X.31, UUS (User-to-user signalling) and nonstandard communications. X.31 will be alot of work, subscribing to it is _very_ expensive here in Germany and what you gain from using it is 16kbit/sec instead of 64kbit/sec which you have over the B-channel. IMHO its not worth to implement it. UUS: subscribing to it is relatively expensive, the remote side has to subscribe to it too to make it useful and it gives you IIRC 32 bytes messages over the D-channel. I dont see any usefulness in that to work on it .... Nonstandard: Because you are not charged anything here for a call setup unless the call is not taken at the other end, i can think of many many ways to transmit information for no charge over the D-channel. But - trying to setup a call on the D-channel reserves a B-channel for a potential communication in the exchange and therefore it is highly illegal to use this kind of "communication" because resources are reserved which are not going to be used. That type of "communication" will not go into i4b. hellmuth -- Hellmuth Michaelis Tel +49 40 559747-70 HCS Hanseatischer Computerservice GmbH Fax +49 40 559747-77 Oldesloer Strasse 97-99 Mail hm [at] hcs.de 22457 Hamburg WWW http://www.hcs.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message