curt@cynic.wimsey.bc.ca (Curt Sampson) (05/16/91)
Well, the initial solution was obvious. I thought that I'd buy a Telebit 2500 and get both. Until I compared the price with the contents of my bank account. :-( At any rate, I need a cheap high-speed modem. It's primarially for UUCP work with a local site that I'm currently exchanging 1.5-2 MB per day with. That site has T2500s on the lines, so it can handle either V.32 or Telebit protocols. The primary advantages of the Telebit seem to be the higher transfer rate (in part due to UUCP spoofing) and better support under Unix (I run SCO Xenix 286 2.3.2). The primary adavantages of the V.32 seem to be that they are better for interactive use (I have several interactive users, and one of the computers I call regularly has a couple of V.32 modems as well as a Telebit) and they are slightly cheaper. Does anybody have any recommendations on what I should get? What kind of UUCP transfer rates can I expect from each kind of modem? Is anybody out there selling Telebits really cheaply? What about V.32 modems? Thanks for the advice. cjs -- Curt Sampson | "It is actually a feature of UUCP that the map of curt@cynic.uucp | all systems in the network is not known anywhere." curt@cynic.wimsey.bc.ca | --Berkeley Mail Reference Manual (Kurt Schoens)
sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) (05/17/91)
Ever try looking into a T1600? $585 from Maya computer... -- No matter what you do, somebody always knew that you would...
emv@ox.com (Ed Vielmetti) (05/17/91)
> site has t2500s on the lines; primarily for UUCP
the T1600 has g-proto spoofing and v.32, you might look into that.
--Edpalkovic@linac.fnal.gov (John Palkovic) (05/17/91)
>>>>> On 16 May 91 22:29:27 GMT, sjhg9320@uxa.cso.uiuc.edu
(Maximum Slackness ) said:
Maximum> Ever try looking into a T1600?
Maximum> $585 from Maya computer...
I have in hand a price list from Discovery Electronics, Marietta GA,
404-956-9100. Here it is:
T-1000 $514
T-1600 $479
Trailblazer Plus $749
T-2500 $870
-Johndavew@gold.gvg.tek.com (David C. White) (05/17/91)
In article <1991May16.222927.29492@ux1.cso.uiuc.edu> sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) writes: >Ever try looking into a T1600? > >$585 from Maya computer... > Right, the T1600 does V.32 and UUCP spoofing. I've had good luck with several modem purchases from Michigan Network Systems. Their latest price for the T1600 was $499 for quantities of 1-9. They can be reached at (800) - 736-5984 or FAX: 313-343-2928.
larry@nstar.rn.com (Larry Snyder) (05/17/91)
sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) writes: >Ever try looking into a T1600? I wouldn't even suggest a T1600 with V.32bis modems offering 50% more in throughput -- for only a small (if any) additional amount. We feed a site via v.32bis 12 megabytes a day - and throughput runs from 1630-1790 cps (compressed - using 16 bit) We also feed 30 sites via PEP and at best we get 1400 cps. -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
larry@nstar.rn.com (Larry Snyder) (05/17/91)
emv@ox.com (Ed Vielmetti) writes: >> site has t2500s on the lines; primarily for UUCP >the T1600 has g-proto spoofing and v.32, you might look into that. we get better throughput with v.32bis with no spoofing than what is possible with v.32 with spoofing -- 1700 cps verses what, 1200 cps? -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
peter@ficc.ferranti.com (Peter da Silva) (05/18/91)
In article <1991May16.150546.26870@cynic.wimsey.bc.ca> curt@cynic.wimsey.bc.ca (Curt Sampson) writes: > The primary advantages of the Telebit seem to be the higher transfer > rate (in part due to UUCP spoofing) and better support under Unix (I > run SCO Xenix 286 2.3.2). In addition, the Telebit handles noisy lines better. If possible, you should get both modems on evaluation and see how they work on your particular setup. If you can't manage that, then try to evaluate the line quality. A 1200 baud modem is good at this, as 1200 baud modems are the worst at dealing with bad lines (yes, 2400 works better than 1200!). > of UUCP transfer rates can I expect from each kind of modem? Is > anybody out there selling Telebits really cheaply? What about V.32 > modems? Detroit Direct Marketing is supposed to have a good deal on modems, but there have been reports that they are sleazy. Their behaviour on Usenet tends to support these rumors. -- Peter da Silva; Ferranti International Controls Corporation; +1 713 274 5180; Sugar Land, TX 77487-5012; `-_-' "Have you hugged your wolf, today?"
rfarris@rfengr.com (Rick Farris) (05/18/91)
In article <2340@gold.gvg.tek.com> davew@gold.gvg.tek.com (David C. White) writes: | Right, the T1600 does V.32 and UUCP spoofing. I've had good luck with | several modem purchases from Michigan Network Systems. Their latest | price for the T1600 was $499 for quantities of 1-9. Wait a minute, isn't Michigan Network Systems the latest pseudonym for John Palmer, the Scourge of The Net?
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) (05/18/91)
In article <1991May16.150546.26870@cynic.wimsey.bc.ca> you write:
"The primary advantages of the Telebit seem to be the higher transfer
"rate (in part due to UUCP spoofing) and better support under Unix (I
"run SCO Xenix 286 2.3.2).
"
Correct. PEP utilizes as much of the telephone line bandwidth as it
can and, unlike V.32, can recover if the line quality gets bad and
it has to fall back. V.32 will fall back to half-speed with a noisy
line and then will quit altogether if things get worse.
PEP can fall back in increments of 100 baud and can recover the speed
if the line quality gets better. Once V.32 downshifts, it cannot
recover.
"The primary adavantages of the V.32 seem to be that they are better
"for interactive use (I have several interactive users, and one of the
"computers I call regularly has a couple of V.32 modems as well as a
"Telebit) and they are slightly cheaper.
"
Telebit's work fine for interactive as well as UUCP/KERMIT/X/YMODEM.
"Does anybody have any recommendations on what I should get? What kind
"of UUCP transfer rates can I expect from each kind of modem? Is
"anybody out there selling Telebits really cheaply? What about V.32
"modems?
"
T1000 in PEP mode: MAX=960cps, AVG=850cps
T2500 in PEP mode: MAX=1920cps, AVG=1150cps
V.32: I have no stats for these.
--
Michigan Network Systems Technical Support Division
1-800-736-5984 BBS: +1 313 343 0800 E-MAIL: tech@mich-ns.Michigan.COM
TELEBIT DIGIBOARD WESTERN DIGITAL 3COM SCO INTERACTIVE UNIX
MICROPOLIS ADAPTEClarry@nstar.rn.com (Larry Snyder) (05/18/91)
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: >T1000 in PEP mode: MAX=960cps, AVG=850cps >T2500 in PEP mode: MAX=1920cps, AVG=1150cps >V.32: I have no stats for these. v.32 - 1100 cps v.32bis - 1750 cps we get 1750 cps doing uucp with v.32bis on a regular basis without uucp spoofing -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
conrad@popvax.uucp (M20400@c.nobili) (05/19/91)
In article <1991May16.222927.29492@ux1.cso.uiuc.edu> sjhg9320@uxa.cso.uiuc.edu (Maximum Slackness ) writes: >Ever try looking into a T1600? > >$585 from Maya computer... > >-- > > No matter what you do, somebody always knew that you would... Get a USR Courier V.32bis. Elek-Tek quoted me a price of $599. You get a LOT more for not much more. Elek-Tek can be reached at (800) 395-1000. They are in Skokie, IL, like USR -- I don't know if that means anything.... I just got a pair of USR Courier V.32bis modems. I had previously had a USR Courier V.32 and a Telebit T2500 hooked together. The improvement is dramatic. It is very nice not to be limited by the Telebit's DTE rate of only 19,200 bps. I had been being choked by that for months, as most of my network traffic is quite compressible. (Well, I suppose that only a little potential throughput was being lost most of the time, with a link rate of only 9,600 bps -- but it felt bad anyway....) With a link rate of 14,400 bps, the 38,400 bps DTE rate really gets used when moving compressible data. By upgrading the two modems I have gotten 2X the thoughput of before with compressible data, and 1.5X the throughput of before with non-compressible data. In addition, I expect to have many fewer strange little problems. It is clear from the bulk of the traffic in this newsgroup that mixing brands and models of modem often leads to headaches, RTFMing, more headaches, and ultimately a post here asking if there are others who have seen the same problems. I know that I am fortunate not to need to communicate with tens of other sites with lots of different modems. (Although I would expect to be more than amply equipped with these new modems (or the old ones, for that matter)....) Having tired of all the ROM upgrades necessary to get modems to talk to each other, this time I got a PAIR, specially requesting consecutive serial numbers. I think THAT should ensure that they have the same chips! Well, I thought the price was good and worth mentioning. (I found it a week after having paid $50 more -- wah! :-( ) +---- C o n r a d C . N o b i l i ----+ | | | Harvard University | Internet: conrad@harvarda.harvard.edu | | Office for Info. Tech. | conrad@popvax.harvard.edu | | Information Services | BITNET: CONRAD AT HARVARDA | | Technical & User Services | CONRAD AT HARVSPHB | | 1730 Cambridge Street | voice: (617) 495-8554 | +---- Cambridge, MA 02138 | fax: (617) 495-0715 ----+
paul@frcs.UUCP (Paul Nash) (05/19/91)
Thus spake larry@nstar.rn.com (Larry Snyder): > tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: > >T1000 in PEP mode: MAX=960cps, AVG=850cps > >T2500 in PEP mode: MAX=1920cps, AVG=1150cps > >V.32: I have no stats for these. > v.32 - 1100 cps > v.32bis - 1750 cps A lot depends on the quality of your phone lines. On local (< 100 km) calls, I get ~ 1000 cps with PEP and UUCP spoofing. On trans-Atlantic calls, I get ~ 300 cps with PEP and UUCP spoofing. However, the trans- Atlantic stuff won't connect in V.32 mode, and barely hold the line with v.22bis. If your lines are not perfect, get the Trailblazer. ---=---=---=---=---=---=---=---=---=---=---=---=---=---=---=---=---=--- Paul Nash Free Range Computer Systems cc paul@frcs.UUCP ...!uunet!m2xenix!frcs!paul
larry@nstar.rn.com (Larry Snyder) (05/19/91)
rfarris@rfengr.com (Rick Farris) writes: >In article <2340@gold.gvg.tek.com> davew@gold.gvg.tek.com (David C. White) writes: >| Right, the T1600 does V.32 and UUCP spoofing. I've had good luck with >| several modem purchases from Michigan Network Systems. Their latest >| price for the T1600 was $499 for quantities of 1-9. >Wait a minute, isn't Michigan Network Systems the latest >pseudonym for John Palmer, the Scourge of The Net? yep - that's the same guy and company -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
larry@nstar.rn.com (Larry Snyder) (05/19/91)
conrad@popvax.uucp (M20400@c.nobili) writes: >Get a USR Courier V.32bis. Elek-Tek quoted me a price of $599. You get a LOT >more for not much more. Elek-Tek can be reached at (800) 395-1000. They are >in Skokie, IL, like USR -- I don't know if that means anything.... >It is very nice not to be limited by the Telebit's DTE rate of only 19,200 bps. >I had been being choked by that for months, as most of my network traffic is >quite compressible. (Well, I suppose that only a little potential throughput >was being lost most of the time, with a link rate of only 9,600 bps -- but it >felt bad anyway....) >With a link rate of 14,400 bps, the 38,400 bps DTE rate really gets used when >moving compressible data. By upgrading the two modems I have gotten 2X the >thoughput of before with compressible data, and 1.5X the throughput of before >with non-compressible data. I agree. Like I said - we get around 1720 cps sending news via USR V.32 with v.32bis daily (sending 10-14 megs a day).. uucp spoofing and the PEP comes into play with noisy lines - but for domestic use - and excellent on-line interaction - v.32bis is a much better alternative we (nstar.rn.com and zztop.rn.com) have a variety of PEP and V.32 modems and can give you averages for each modem -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
peter@ficc.ferranti.com (Peter da Silva) (05/19/91)
In article <6815@husc6.harvard.edu> conrad@popvax.uucp (M20400@c.nobili) writes: > In addition, I expect to have many fewer strange little problems. It is clear > from the bulk of the traffic in this newsgroup that mixing brands and models > of modem often leads to headaches... Of course this means if you're doing UUCP, get a trailblazer... since that's what most of the people doing UUCP are still using. -- Peter da Silva; Ferranti International Controls Corporation; +1 713 274 5180; Sugar Land, TX 77487-5012; `-_-' "Have you hugged your wolf, today?"
conrad@popvax.uucp (M20400@c.nobili) (05/20/91)
In article <R_EB7J7@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes: >In article <6815@husc6.harvard.edu> conrad@popvax.uucp (M20400@c.nobili) writes >> In addition, I expect to have many fewer strange little problems. It is clear >> from the bulk of the traffic in this newsgroup that mixing brands and models >> of modem often leads to headaches... > >Of course this means if you're doing UUCP, get a trailblazer... since that's >what most of the people doing UUCP are still using. Yes, try to match modem pairs as closely as possible. My point was really more that if one had the luxury of having the whole dialup network under one's own control one ought to consider seriously not upgrading by parts, but rather wait- ing until one could afford to upgrade the whole thing at once. And when doing that, consider asking for consecutive serial numbers like I did. I *know* that this is impractical advice for most people, but there must be others out there like me who have network bridges involving only two modems.... You may be right about using a TrailBlazer if you are doing UUCP, but it looks from the traffic here that there are various little inconsistencies even when going Telebit to Telebit using PEP when different models or firmware versions are involved. Mind you, it seems that most of these can be gotten around, by posting something here and having Greg answer with the magic S-register values. And I have found both USR and Telebit tech support to be very good, and both companies to be reasonable about sending ROM upgrades. (I have had to do this with both brands in the past....) I was just expressing my pleasure at having two basically _identical_ modems now.... I don't want to fuel the USR vs Telebit fires, but I think I prefer the USRs. It sounds like I might say otherwise if I had to exchange data over noisy over- seas lines (very noisy, I think) or had to exchange UUCP data only with other PEP modems (especially not the V.32-also type). >Peter da Silva; Ferranti International Controls Corporation; +1 713 274 5180; >Sugar Land, TX 77487-5012; `-_-' "Have you hugged your wolf, today?" +---- C o n r a d C . N o b i l i ----+ | | | Harvard University | Internet: conrad@harvarda.harvard.edu | | Office for Info. Tech. | conrad@popvax.harvard.edu | | Information Services | BITNET: CONRAD AT HARVARDA | | Technical & User Services | CONRAD AT HARVSPHB | | 1730 Cambridge Street | voice: (617) 495-8554 | +---- Cambridge, MA 02138 | fax: (617) 495-0715 ----+
rodney@tyrell.stgt.sub.org (Rodney Volz) (05/20/91)
In article <1991May17.131523.10111@nstar.rn.com> larry@nstar.rn.com (Larry Snyder) writes: > Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 > HST/PEP/V.32/v.32bis/v.42bis HST, Pep *_and_* V32bis?! Which modem(s) do you use? -Rodney -- Rodney Volz - 7000 Stuttgart 1 - FRG ============> ...uunet!mcsun!unido!gtc!aragon!tyrell!rodney <============= rodney@tyrell.gtc.de * rodney@delos.stgt.sub.org * rodney@mcshh.hanse.de \_____________ May your children and mine live in peace. ______________/
petty@ralvm31.vnet.ibm.com ("Jack Petty") (05/20/91)
Ref: article of 16 May by tech@mich-ns.Michigan.COM I think it is important to differentiate between the requirements in the V.32 recommendation and the implementations of V.32 done by different vendors. The author writes: > V.32 will fall back to half-speed with a noisy > line and then will quit altogether if things get worse. > > Once V.32 downshifts, it cannot recover. Both points are implementation decisions. The author may be very familiar with the T2500 and assumes incorrectly that all V.32 modems must behave the same way. I have seen one V.32 modem that does not fall back at all - it just goes on-hook if the connection degrades. I have seen another that will fall back from 9600 bps to 4800 bps and then from 4800 bps down to V.22 bis 2400 bps. I have also seen a V.32 modem that will fall forward from 4800 bps to 9600 bps. For me, all of these can be considered to meet the requirements of the V.32 recommendation. The author also indicates Telebits work "fine" for interactive use. "Fine" is often a matter of personal taste. What is the single character round trip time? I think the IBM 7855 is a typical V.32 modem and its single character round trip time is in the range of 60 to 130 milliseconds (depending on whether MNP or compression is turned on). I would expect a USR modem with its slow speed back channel to be about the same for single characters. Have I read that for the Telebit proprietary modulation scheme it takes about 1 second to turn the line around? Jack Petty
mra@searchtech.com (Michael Almond) (05/20/91)
In article <+3P9XVF@linac.fnal.gov> palkovic@linac.fnal.gov writes: >I have in hand a price list from Discovery Electronics, Marietta GA, >404-956-9100. Here it is: > >T-1600 $479 I called them this morning and they quoted me a price of $549. However, they said they would meet anyone else's price. -- Michael R. Almond (Georgia Tech Alumnus) mra@srchtec.uucp (registered) search technology, inc. mra@searchtech.com 4725 peachtree corners cir., suite 200 uupsi!srchtec!mra norcross, georgia 30092 (404) 441-1457 (office)
lancelot@UUCP (Thor Lancelot Simon) (05/20/91)
In article <1991May16.150546.26870@cynic.wimsey.bc.ca> curt@cynic.wimsey.bc.ca (Curt Sampson) writes: > The primary advantages of the Telebit seem to be the higher transfer > rate (in part due to UUCP spoofing) and better support under Unix (I > run SCO Xenix 286 2.3.2). [...] > of UUCP transfer rates can I expect from each kind of modem? Is > anybody out there selling Telebits really cheaply? What about V.32 > modems? We bought two T2500s a few months back for $870, a then excellent price. I don't know what Telebits usually run for these days, but I imagine if the market price has gone down, so has the retailers. In general, we found that support from both Telebit and the retailer was excellent. I also find that we get much better transfer rates with PEP than with borrowed V.32bis modems. PEP tends to rely very heavily on flow control, and I'd guess that systems with slow RTS/CTS transition might suffer from this. I know that a T2500 on a DMF32 does slightly better than one on a DHU11, though the DHU has DMA and ergo loads the CPU less. But what do I know? PEP also has exhibited (to me) far better real-world performance than V.32. I've never compared it to V.32bis, but with more frequencies I'd imagine V.32bis is probably if anything less stable than the original. I've never made a reliable (lasting) overseas V.32 connection, with a 2500 or an Ultra Smartmodem - but PEP never gives me any trouble. The dealer we bought our 2500s from was: AnDATAco 9550 Waples St. San Diego, CA 92121 (805) 523-9191 We spoke to Josh Wells. We got their address from somebody else's post to (I think) news.admin. address from. -- ******************************************************************************* *Thor Simon * Okay, just a little pin-prick...There'll be no more-* *lancelot@spock.UUCP * Aieeeeaaaugh!-but you may feel a little _sick_. * *decwrl!spock!lancelot * ---Pink Floyd *
steve@endgame.gsfc.nasa.gov (Steve Rezsutek) (05/21/91)
In article <1991May20.151905.11586@spock.UUCP> lancelot@UUCP (Thor Lancelot Simon) writes:
We bought two T2500s a few months back for $870, a then excellent price. I
don't know what Telebits usually run for these days, but I imagine if the
market price has gone down, so has the retailers. In general, we found that
support from both Telebit and the retailer was excellent.
Before I bought my T2500 (January), I shopped all over for the best price.
I finally purchased it through Uunet ($909 incl. shipping, I believe), even
though a few places had it for $10 or $20 less. Since that time, I've seen
the price go _up_ in several of the mail order places to around $990.
(Mileage may vary, of course). I'm not sure if Uunet's price has changed, so
it would be best to contact them. Like you, I've had great support as well.
(Never thought I'd fall victim to `brand loyalty', but Telebit has won it :-)mra@searchtech.com (Michael Almond) (05/22/91)
In article <STEVE.91May21103744@endgame.gsfc.nasa.gov> steve@endgame.gsfc.nasa.gov (Steve Rezsutek) writes: > ... I'm not sure if Uunet's price has changed, so >it would be best to contact them. Like you, I've had great support as well. You can anonymous ftp to uunet.uu.net and look in uunet-info/modem-prices for their latest price. The T1600 is $549 and T2500 is $899. -- Michael R. Almond (Georgia Tech Alumnus) mra@srchtec.uucp (registered) search technology, inc. mra@searchtech.com 4725 peachtree corners cir., suite 200 uupsi!srchtec!mra norcross, georgia 30092 (404) 441-1457 (office)
glenn@gla-aux.uucp (Glenn Austin) (05/22/91)
In article <1991May16.150546.26870@cynic.wimsey.bc.ca>, curt@cynic.wimsey.bc.ca (Curt Sampson) writes: > Well, the initial solution was obvious. I thought that I'd buy a > Telebit 2500 and get both. Until I compared the price with the > contents of my bank account. :-( > > At any rate, I need a cheap high-speed modem. It's primarially for > UUCP work with a local site that I'm currently exchanging 1.5-2 MB per > day with. That site has T2500s on the lines, so it can handle either > V.32 or Telebit protocols. > > The primary advantages of the Telebit seem to be the higher transfer > rate (in part due to UUCP spoofing) and better support under Unix (I > run SCO Xenix 286 2.3.2). > > The primary adavantages of the V.32 seem to be that they are better > for interactive use (I have several interactive users, and one of the > computers I call regularly has a couple of V.32 modems as well as a > Telebit) and they are slightly cheaper. > > Does anybody have any recommendations on what I should get? What kind > of UUCP transfer rates can I expect from each kind of modem? Is > anybody out there selling Telebits really cheaply? What about V.32 > modems? I use a V.32 modem for my primary feed, but due to the fact that the modem on the other end doesn't support LAPM (V.42bis 4:1 compression), I simply turned off all compression. Since my news:mail ratio is roughly 100:1, I can live with only 9600 baud. However, if someone put a V.42bis modem on the other end, I certainly wouldn't mind... Seriously, I also considered the T2500, but since V.32 and V.42bis are relatively new standards in the telecom marketplace, getting a modem without them is like getting a 300-baud modem 3 years ago. =============================================================================== | Glenn L. Austin | "Turn too soon, run out of room. | | Macintosh Wizard and | Turn too late, much better fate." | | Auto Racing Driver | -- Jim Russell Racing School Instructors | |-----------------------------------------------------------------------------| | Usenet: glenn@gla-aux.uucp | CI$: 76354,1434 | | GENie: G.AUSTIN3 | AOnline: GAustin | ===============================================================================
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) (05/23/91)
In article <1991May19.135247.11010@nstar.rn.com> larry@nstar.rn.com (Larry Snyder) writes: >rfarris@rfengr.com (Rick Farris) writes: " ">In article <2340@gold.gvg.tek.com> davew@gold.gvg.tek.com (David C. White) writes: " ">| Right, the T1600 does V.32 and UUCP spoofing. I've had good luck with ">| several modem purchases from Michigan Network Systems. Their latest ">| price for the T1600 was $499 for quantities of 1-9. " ">Wait a minute, isn't Michigan Network Systems the latest ">pseudonym for John Palmer, the Scourge of The Net? " Same company. -- Michigan Network Systems Technical Support Division 1-800-736-5984 BBS: +1 313 343 0800 E-MAIL: tech@mich-ns.Michigan.COM TELEBIT DIGIBOARD WESTERN DIGITAL 3COM SCO INTERACTIVE UNIX MICROPOLIS ADAPTEC
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) (05/23/91)
In article <R_EB7J7@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes: "In article <6815@husc6.harvard.edu> conrad@popvax.uucp (M20400@c.nobili) writes: "> In addition, I expect to have many fewer strange little problems. It is clear "> from the bulk of the traffic in this newsgroup that mixing brands and models "> of modem often leads to headaches... " "Of course this means if you're doing UUCP, get a trailblazer... since that's "what most of the people doing UUCP are still using. Mixing brands doesn't cause headaches, the plethora of different modulations compression and error correction schemes sometimes cause a problem. One of the biggest problems is the answer sequence. Sometimes, modems get confused when confronted with an answer sequence which it mistakes for some other kind of tone. I know, this shouldn't happen, but it often times does. The next problem has to do with error correction schemes causing the link to drop. This is true with V.42/V.42bis in some cases. -- Michigan Network Systems Technical Support Division 1-800-736-5984 BBS: +1 313 343 0800 E-MAIL: tech@mich-ns.Michigan.COM TELEBIT DIGIBOARD WESTERN DIGITAL 3COM SCO INTERACTIVE UNIX MICROPOLIS ADAPTEC
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) (05/23/91)
In article <490@frcs.UUCP> paul@frcs.UUCP (Paul Nash) writes: "Thus spake larry@nstar.rn.com (Larry Snyder): "> tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: "> >T1000 in PEP mode: MAX=960cps, AVG=850cps "> >T2500 in PEP mode: MAX=1920cps, AVG=1150cps "> >V.32: I have no stats for these. "> v.32 - 1100 cps "> v.32bis - 1750 cps " "A lot depends on the quality of your phone lines. On local (< 100 km) "calls, I get ~ 1000 cps with PEP and UUCP spoofing. On trans-Atlantic "calls, I get ~ 300 cps with PEP and UUCP spoofing. However, the trans- "Atlantic stuff won't connect in V.32 mode, and barely hold the line "with v.22bis. If your lines are not perfect, get the Trailblazer. " " Thats whats nice about PEP. With V.32, if the line gets noisy, its drops back to half its normal speed (usually 4800bps). If the line gets even worse, it will drop the connection altogether. Even if the connection doesn't drop, V.32 cannot re-train back up to a higher speed. PEP can drop backwards in increments of as little as 100 baud AND can speed up again, if line conditions get better. -- Michigan Network Systems Technical Support Division 1-800-736-5984 BBS: +1 313 343 0800 E-MAIL: tech@mich-ns.Michigan.COM TELEBIT DIGIBOARD WESTERN DIGITAL 3COM SCO INTERACTIVE UNIX MICROPOLIS ADAPTEC
larry@nstar.rn.com (Larry Snyder) (05/23/91)
rodney@tyrell.stgt.sub.org (Rodney Volz) writes: >In article <1991May17.131523.10111@nstar.rn.com> larry@nstar.rn.com (Larry Snyder) writes: >> Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 >> HST/PEP/V.32/v.32bis/v.42bis >HST, Pep *_and_* V32bis?! >Which modem(s) do you use? Telebits and USR Dual Standards -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
larry@nstar.rn.com (Larry Snyder) (05/23/91)
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: >Thats whats nice about PEP. With V.32, if the line gets noisy, its drops >back to half its normal speed (usually 4800bps). If the line gets even >worse, it will drop the connection altogether. Even if the connection >doesn't drop, V.32 cannot re-train back up to a higher speed. >PEP can drop backwards in increments of as little as 100 baud AND can >speed up again, if line conditions get better. So can v.32bis - and v.32bis also provides much better interactive throughput since it is a duplex connection at high speed :) v.32bis offers much better throughput on domestic lines of marginal quality - whereas PEP is the only modem for international connections -- Larry Snyder, NSTAR Public Access Unix 219-289-0287/317-251-7391 HST/PEP/V.32/v.32bis/v.42bis regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar.rn.com!larry}
lstowell@pyrnova.pyramid.com (Lon Stowell) (05/24/91)
In article <48@mich-ns.Michigan.COM> tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: >" >Thats whats nice about PEP. With V.32, if the line gets noisy, its drops >back to half its normal speed (usually 4800bps). If the line gets even >worse, it will drop the connection altogether. Even if the connection >doesn't drop, V.32 cannot re-train back up to a higher speed. > >PEP can drop backwards in increments of as little as 100 baud AND can >speed up again, if line conditions get better. > This is a FQM...a Frequently Quoted Myth. There is nothing in V.32 or V.32bis which precludes shifting from a lower to a higher speed. The fact that few modem vendors have IMPLEMENTED the capability has nothing to do with the fact that a V.32 modem can request a retrain...and in that retrain, specify the baud rate...higher or lower. If ONE of the modems can do a fall-forward..and asks for a retrain to 9600, a compliant modem will shift....although it might request a drop back to 4800 if the "probability of error" is too high for 9600 or the train fails. V.32 notes only the training and retraining sequences...which include the Rate Signal as part. it does not specify either fallback or fallforward explicity....only that "a retrain may be initiated during data transmission if either modem incorporates a means of detecting unsatisfactory signal reception. Figure 5a/V.32 shows a retrain event initiated by the calling modem and Figure 5B/V.32 shows a retrain event initiated by the answering modem..... (5.5 Retrain Procedure.) Some vendors have interpreted this to mean that excessive errors should cause a fallback...so they retrain and request a lower rate. There is nothing to preclude interpretation that the error rate is to LOW and a higher rate would be possible. A retrain with a baud rate is a retrain...period. The V.32 training sequence is half duplex..and interrupts the line for several seconds. Many vendors will stay at the lower rate once fallback has been done UNLESS the DTE requests the higher rate via Ckt 111. Others will fall forward. Admittedly, gearshift modems are rare in V.32, but all the V.32bis modem's I've seen offer it standard.
rdippold@cancun.qualcomm.com (Ron Dippold) (05/24/91)
In article <48@mich-ns.Michigan.COM> tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: >Thats whats nice about PEP. With V.32, if the line gets noisy, its drops >back to half its normal speed (usually 4800bps). If the line gets even >worse, it will drop the connection altogether. Even if the connection >doesn't drop, V.32 cannot re-train back up to a higher speed. > >PEP can drop backwards in increments of as little as 100 baud AND can >speed up again, if line conditions get better. V.32 modems _do_ have the option to fall forward. However, both modems have to support it and most brands do not. -- Standard disclaimer applies, you legalistic hacks. | Ron Dippold
randy@m2xenix.psg.com (Randy Bush) (05/26/91)
tech@mich-ns.Michigan.COM (Mich. Network Sys. TECH SUPPORT) writes: > With V.32, if the line gets noisy, its drops back to half its normal speed > (usually 4800bps). If the line gets even worse, it will drop the connection > altogether. Even if the connection doesn't drop, V.32 cannot re-train back up > to a higher speed. V.32 modems can fall forward as well as back. Few implementations are of sufficient quality to do so, but that's life in the big city. Back under your rock, Palmer-dewwb. -- randy@psg.com ..!uunet!m2xenix!randy