Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!ucsd!nic.cerf.net!bdavis From: bdavis@nic.cerf.net (Barry Davis) Newsgroups: comp.dcom.modems Subject: Re: Stop me before I kill (uucico) again... Summary: Clarification: MNP problem... Keywords: HDB uucp modem Message-ID: <349@nic.cerf.net> Date: 24 Apr 91 14:49:51 GMT References: <704@sunpix.East.Sun.COM> <1991Apr20.104127.14981@netcom.COM> Organization: CERFnet; La Jolla, CA Lines: 98 In article <1991Apr20.104127.14981@netcom.COM>, gandrews@netcom.COM (Greg Andrews) writes: > In article <342@nic.cerf.net> bdavis@nic.cerf.net (Barry Davis) AKA > Cerafin E. Castillo, writes: > > > >I was having similar problems on a leased-line SLIP link using Telebit T2500 > >modems with V.32/V.42/V.42bis/MNP4-5. It seemed that the two T2500 modems > >could not connect when I was using either V.42/V.42bis or MNP4-5 for error > >correction and/or data compression. Upon contacting Telebit, I was told > >there is an apparent problem with using error correction or data compression > >over V.32. > > > > Who did you talk with? I'm certainly not aware of ANY problems getting > a V.32/MNP or V.32/LAP-M link going between two T2500 modems over leased > or dialup lines. > > > > > Since I had tried every possible combination of V.32 and V.42/V.42bis > >/MNP4-5, this seemed to be the only logical answer. I was told that > >a fix was to be included in the next firmware release (Rev. 7.1 ??). > I would like to clarify my report of problems using V.42/MNP over V.32 in Telebit T2500 modems. This is due to this posting and a direct reply I received from Telebit (modems@america.telebit.com). My leased-line SLIP link using Telebit T2500s (GE7.00) and Data Probe hybrids is in line with Telebit recommendations. My leased line is heavily conditioned and I was trying to squeeze a little more performance and stability from SLIP between my two Emulex P400B terminal servers. There were no line problems to be dealt with. Using V.32, I was not able to get V.42/MNP working at all. I was supported by Telebit in my testing, and I know the product settings pretty well by now, so there was little left to chance in so far as modem settings are concerned. I have gone to using Penril Alliance modems since they can do V.42/V.42bis over both V.32 and V.32bis. They are also 4-wire leased line capable. Although I believe, and I was told, that there is a problem with BOTH V.42 and MNP over V.32, this is the direct reply I received from Telebit: |Date: Mon, 22 Apr 91 17:22:33 PDT |From: Telebit Support acct |Message-Id: <9104230022.AA01447> |To: cec@emulex.com |Subject: T2500 V.42 |Status: RO | | |Cerafin, | |I got your reply to David Kessner and when you said "I called Telebit and |they said it was an apparent problem with error correction or data comp." |How did you talk to? We KNOW there is a problem w/ MNP, but we're not aware |of a problem with V.42 or V.42bis. As a matter of fact, when people run into |the MNP problem, we SUGGEST that they use V.42 for their error correction/data |compression as it has no problems. Maybe you need to call Tech. Support so |we can properly configure your modem to work in V.42 mode. It's easy...set |the following: S97=1 S106=1 X3 at BOTH ends and the modems WILL connect in |V.42 mode. I'm doing this e-mail in V.42 mode calling into the Sun, so I |know for a fact that it works.....leased line prob's?...cockpit error? ||GE7.02 and GF7.02 will fix the MNP problems...it'll be out soon. I'll also |reply to David so we can properly straighten him out. | |Jim Tremolini.....Telebit Technical Support. This answered a lot of my questions as to V.42/MNP with V.32... As for your next comment: > > You might want to inquire with Telebit as to your specific problem if flow > >control or V.32 UUCP spoofing has been eliminated as a problem in your > >application. Good Luck! > > > > I don't understand - how could uucp spoofing be a factor between a T2500 > and another brand of modem (ATI)?? Flow control could certainly cause > trouble, but spoofing wouldn't have been enabled. It might cause trouble > for SLIP if it were mistakenly enabled in your setup... > > To address Marc's problem,... [deleted] > Greg Andrews Since Marc's application was UUCP related, I figured that V.32 UUCP spoofing might have played into the picture. Just trying to cover the basics... =============================================================================== Cerafin E. Castillo ______ ______ TCP/IP LAN/WAN Connectivity \ / INET: cec@emulex.com EMULEX Corporation ______ \/ ______ 2880 Zanker Rd., Suite 204 /\ UUCP: uunet!emulex!cec San Jose, CA 95131 ______/ \______ (408) 452-4777 E M U L E X "Beauty does what Beauty does best; it's Beautiful!" ================================================================================