Path: utzoo!attcan!uunet!lll-winken!netsys!vector!telecom-gateway From: desnoyer@apple.com (Peter Desnoyers) Newsgroups: comp.dcom.telecom Subject: Re: Bit-oriented protocols 'standard' for ISDN byte-oriented channels? Message-ID: Date: 11 May 89 17:29:06 GMT Sender: news@vector.Dallas.TX.US Organization: Apple Computer Inc, Cupertino, CA Lines: 35 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 161, message 3 of 10 In article gnu@toad.com (John Gilmore) writes: >X-TELECOM-Digest: volume 9, issue 160, message 1 of 8 >The new Sun SPARCstation-1 uses an ISDN chip for its audio interface >(the AMD Am79C30). The chip is designed for use in an ISDN >speakerphone; it talks the "S" interface (towards the phone network) >on one end, has a micro-oriented 8-bit bus on another, two audio inputs >(mike and handset), and two audio outputs (earpiece and speaker). It >has full SDLC support for the 16kbps "D" channel, but the two 64kbps ^^^^ LAPD. >full-duplex "B" channels are simply accessed a byte at a time. > >It appears that Sun will not support plugging your SPARCstation into an >ISDN phone line, because some standards committee somewhere decided >that, when used for data, the "B" channels should carry SDLC-formatted >data, and the SPARCstation (and the Am79C30) has no support for this. As far as I know it is EXPECTED (not required) that most ISDN data will be HDLC-framed. (e.g. X.25, proposed new packet-mode services) However, V.110 rate-adapted data is not HDLC-framed, and clear-channel data is not necessarily framed, either. Is there a standard restricting the format of clear-channel data to HDLC-framing? Who is responsible for that? What are they going to do about V.110? Names and document numbers would be appreciated - this is news to me and could be a Very Bad Thing. With luck it's just a misinterpretation on someone's part. I find it interesting that there is no HDLC controller on the B channels. How does the SPARCstation perform when it is being interrupted every 125uS? Peter Desnoyers