ross@fdurt1.FDU.EDU (Jeff Ross) (03/11/91)
I have a small delema, we have had for some time a rack of paradyne FDX2400's and a few stand alones, they seem to work fine, or at least they did until about a month or two ago. the problem arose when we purchased some DL424's, we purchased 2 stand alone units and we purchased a rack containing 2 modems (with the intention of filling the rack by purchasing 2 or 3 per semester) well, I had some time to play with the stand alone modems for a little while before the rack came in, and noticed that I couln't talk to my telebit T2500 (had rom rev 6.01 or 6.02???) when an MNP connection was established, if I turned off MNP everything worked fine. (actually, the modems would connect, and I could talk for about 10 min or so, and the connection would be lost, the telebit's atj0j6 command revealed that the modems retrained too many times, and the retrain count was 1, the DL424 just said "NO CARRIER" if I left the speaker on to listen for the retain, it was never heard. ok, I heard that telebit has/had a bug in their rom with mnp connections, so I called telebit thinking it may be their problem, and they where more than happy to send me a new rom, ver 7.01 and they asked me to tell them if it worked. it didn't solve anyproblems so I called telebit back, (BTW, I also had a call into AT&T, it took about 1 1/2 months to hear from them) and I spoke to a very helpful person by the name of Randy Dole who verified my problem and asked if I would be willing to try a beta version of their rom (GE7.02) and of course I said yes. Randy did tell me that this rom fixed all their known problems. well, it doesn't work either, and I shot the theory down that telebit had the bug fixed, or did they and AT&T now has a problem? this is a definate possibility, well, telebit asked me if I could either find somebody for them to talk to at AT&T or have AT&T call him so they can find the bug, Randy said that telebit is interested in deturmining if the problem is theirs or AT&T, and is willing to help to located the problem (I guess telebit obviously wants to fix their problem, and I assume AT&T would want to as well) now, we got 2 of the rack mount DL424's in, supposedly this is the same modem as in their standalone....I'm begining to wonder... if I attempt to place a call from the standalone modem to the rackmount modem, one thinks it has an mnp connection, the other doesn't, ok, I disable mnp on the one that thinks it has the mnp connection, and replace the call, wonderful the other thinks it has an mnp connection! now I'm really getting irratated so I try getting the FDX2400 (also made by AT&T Paradyne) and call the rackmount DL424, I get a 2400bps MNP-3 connection (that is the highest mnp of the FDX2400) like I expected but with a twist....the connection works for about 20 seconds, I get a single burst of data from the modem, and then the "ER" light on the FDX2400 starts blinking, but I can still transmit data to the DL424 and the computer connected to the DL424 receives the data properly, and I can see data going from the host connected to the DL424 to the DL424, if the DL424 is swollowing it or the FDX2400 is swollowing it, I don't know, but if I have the DL424 call the FDX2400 everthing seems to work fine. well, we had several field "engineers" out to our site, I use the term engineers lightly. first time, two guys came out, I don't remember their names. but when I described the first scenario, the first question I was asked was: "What is MNP???" I was floored! here is AT&T sending their engineer's out and they don't even know the products they are working on? I expect the secratary not to know what mnp is, but not the tech! ok, I got past that point, explained the idea behind it, and demonstrated some of the problems. They immediatly called their "private" hotline and spoke to some engineer in florida, and when he was able to duplicate the problem between the DL424 and the FDX2400 they basically left saying that we could call in a day or two and follow up on the problem. well, two weeks of calling (getting through rarely to who we had to speak to) produced one of the original field engineers to our site to retrieve serial numbers, rom revisions and the like from the modems. about a week following that, AT&T sent another engineer out, his name "Joe" (this was friday march 8th) he at least knew what MNP was, or at least he acted as if he did. he again duplicated all the problems that we have been saying that are occuring, and called his hotline in florida. well, after going around in circles for several hours, I finally spoke to the tech in florida, to my amazement, he was as clueless as the field engineer! this was the final clincher, when I spoke the the Tech in florida, and he asked me what type of flow control I was using. I told him, "CTS/RTS" because I needed a full 8-bit data path. well, he responded, I think you should be using XON/XOFF instead. I told he I couldn't because I would no longer have a full 8bit data path. he said sure you will. (at this point I was getting a little disgusted) and he went on to say that CTS/RTS handshaking is very dependant upon what the remote is doing. I tried to explain that I was running the modem at a locked baud rate and that the flow control I used between one modem and its host has nothing to do with what is running on the other host. and when he said, "are you trying to tell me how my product works?" I handed the phone back to the field tech and told him to tell the guy in florida to learn how RS-232 communications work and walked out of the room. about 45 min later, the field tech comes and tells me that I was correct in describing how the serial communications work, and the tech in florida was incorrect. unfortunatly my boss has a loyalty with Paradyne modems (which BTW is wearing _very_ thin) has anybody used any of the above mentioned AT&T equip with any success? or am I not alone? is the service that I have gotten from AT&T about as good as its going to get? personally, I'm itching to send the modems back where they came from and purchase somebody elses modems. at this point it seems as if anybody's would be better than AT&T. comments, suggestions anybody??? Jeff -- .Sig??? you want a stinkin' Sig too???? sheesh Jeff Ross --- Fairleigh Dickinson U. Teaneck, NJ ross@rodney.fdu.edu