dennis@virtech.UUCP (Dennis P. Bednar) (08/16/89)
The following is a short story about a recent problem we have found when trying to connect a Telebit T2500 modem to a Microcom QX/V.32C modem. We recently upgraded the EPROM chips in the Microcom modem from Rev 1.1 to Rev 1.5, and after doing so, the competing vendor modems were no longer able to connect. Because it worked with Rev 1.1 but not Rev 1.5, I am inclined to believe that it is not a configuration problem for either modem. The message below was mailed to local users on our machine: --- There is no errata sheet that describes the enhancements to rev 1.5 firmware for the microcom QX/V.32.C modems. I have installed the new chips in only two of the microcom QX/V32.C modems because there is a problem connecting the Telebit T2500 modem to the Microcom QX/V32 modem. The problem is that they connect initially, then the phone call is immediately disconnected. I called Microcom Technical Support, and told them the problem occured after upgrading the Micocom EPROMS from Rev 1.1 to Rev 1.5. I hesitate to install the new chips into the third modem because there may be a Rev 1.5.1 to come to fix our problem (lets hope!). When I found this problem after installing the chips into the first microcom modem, I did a well-controlled test with the 2nd microcom QX/V32.C modem still containing the old Rev 1.1 chips: I verified that with rev 1.1 of microcom EPROMS, I was able to dial in BOTH directions (out of the telebit T2500 into the Microcom QX/V.32, and vice versa). I did this with a cu(1) running on both modems. I then installed the Rev 1.5 chips into the 2nd Microcom modem, and repeated the same test. In both tests, each modem connected, then dropped the phone call within a fraction of a second later. In a few rare cases, a few characters typed into the Microcom modem were transmitted successfully to the terminal at the Telebit T2500 end. I spoke to "Nat" at Microcom about this problem. Nat also verified that his Microcom could not communicate with our Telebit modem (by calling our Telebit from his Microcom modem). The results were the same as what I saw when I did the above tests. His engineers will check into the problem and he will call us back. -dennis
jparnas@larouch.uucp (Jacob Parnas) (08/18/89)
In article <1018@virtech.UUCP> dennis@virtech.UUCP (Dennis P. Bednar) writes: >... >The following is a short story about a recent problem we >have found when trying to connect a Telebit T2500 modem >to a Microcom QX/V.32C modem. We recently upgraded the >EPROM chips in the Microcom modem from Rev 1.1 to Rev 1.5, >and after doing so, the competing vendor modems were no >longer able to connect. Because it worked with Rev 1.1 >but not Rev 1.5, I am inclined to believe that it is not >a configuration problem for either modem. The message >below was mailed to local users on our machine: >... I just connected to our Telebit T2500 from a Microcom QX/V.32c with no problem whatsoever. I'm running the 1.5 revision of the EPROMS too. A possible problem might be that you have result codes set on on the receiving modem, which on our machines would sometimes make the modem hang up because getty would echo the CONNECT message before the modem had totally switched from command mode, and cause the hang up. This may not be the problem, but I know that I have connected many times between the two modems that you have had problems with. If you contact me, you can try calling up my Telebit and/or Microcom from your Telebit and or Microcom. I'm running these modems off of an RT PC running 4.3 BSD UNIX. ------------------------------------------------------------------------------ | Jacob M. Parnas | DISCLAIMER: The above message is from | | IBM Thomas J. Watson Research Ctr. | me and is not from my employer. IBM | | Arpanet: jparnas@ibm.com | might completely disagree with me. | | Bitnet: jparnas@yktvmx.bitnet \---------------------------------------| | Home: ..!uunet!bywater!acheron!larouch!jparnas | Phone: (914) 945-1635 | ------------------------------------------------------------------------------