Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!sdd.hp.com!spool2.mu.edu!uunet!hayes!tnixon From: tnixon@hayes.uucp Newsgroups: comp.dcom.modems Subject: Re: Problem getting Hayes V-Series Smartmodem 9600 to connect to T2500 Message-ID: <3712.2783288c@hayes.uucp> Date: 3 Jan 91 12:50:20 GMT References: <567@fciva.FRANKLIN.COM> Distribution: na Organization: Hayes Microcomputer Products, Norcross, GA Lines: 35 In article <567@fciva.FRANKLIN.COM>, dag@fciva.FRANKLIN.COM (Daniel A. Graifer) writes: > I have an Hayes V-Series Smartmodem 9600 modem connected to my Mac. > I can talk to the modem just fine. I want to call our unix host in > v32/v42 mode. The host has a Telebit T2500, which will operate at > v32/9600bps. The V-series Smartmodem 9600 uses a proprietary, non-standard fast-turnaround ping-pong modulation scheme above 2400bps. Although some aspects of this modulation are LIKE V.32 (it uses trellis coding and a similar constellation), it is NOT compliant with CCITT V.32 and will NOT communicate with anything but another Hayes modem above 2400bps. This is similar to the situation that exists with the Telebit Trailblazer Plus -- standard up to 2400, but proprietary above 2400. The Hayes Ultra 96 (V-series ULTRA Smartmodem 9600) supports _real_ compliant V.32 at 4800 and 9600. It connects just fine with the T1500 and T2500, as well as previous VSM9600s. This is similar in philosophy to the T2500 -- the Ultra 96 supports both the standard V.32 modulation _and_ Hayes' proprietary ping-pong modulation at 9600. You shouldn't get a "NO CARRIER" when calling a T2500 with a VSM9600; they should in fact connect at 2400bps, which is the highest speed they have in common. -- Toby -- Toby Nixon, Principal Engineer | Voice +1-404-449-8791 Telex 151243420 Hayes Microcomputer Products Inc. | Fax +1-404-447-0178 CIS 70271,404 P.O. Box 105203 | UUCP uunet!hayes!tnixon AT&T !tnixon Atlanta, Georgia 30348 USA | Internet hayes!tnixon@uunet.uu.net