jr@amanue.UUCP (Jim Rosenberg) (07/24/88)
I would like to hear of any experiences anyone may have had with direct dial
modem connections between the USA and France. The company I work for has a
prospective customer in France, and if we do the installation it will require
a reliable modem connection -- the expense of sending someone over there if
things go wrong is just too much. All of our systems go out the door with
modems, and we insist on a dedicated line. The modems we are spec'ing are
Multitech 2400 internal modems. I'm not sure just which MNP level they
support, but I believe it's Class 5. (If it's only Class 4 I'm sure an
upgrade ROM to Class 5 is available.) I've never played with setting up these
modems for MNP mode, but I'd assume it would help a lot. How dirty are the
lines to France? I would think with the ability to go MNP we shouldn't have
too much trouble. The most frequent use of the modem will be for interactive
terminal sessions, but we'd be doing some file transfer too.
I'd appreciate hearing about any war stories.
--
Jim Rosenberg
CIS: 71515,124 decvax!idis! \
WELL: jer allegra! ---- pitt!amanue!jr
BIX: jrosenberg uunet!cmcl2!cadre! /dave@westmark.UUCP (Dave Levenson) (07/24/88)
In article <297@amanue.UUCP>, jr@amanue.UUCP (Jim Rosenberg) writes: > ...The modems we are spec'ing are > Multitech 2400 internal modems... Check with Multitech or with the PTT in France. You may find that it is not legal to connect these devices to the public switched network there. My literature from Multitech mentions only FCC part 15 and part 68. It doesn't mention any type-acceptance data for any other country. I have been involved recently in the development of a computer peripheral that plugs into an XT-buss slot like an internal modem, and connects to a telephone line through a standard modular jack. The device was tested and accepted as complying with FCC part 15 (radio-frequency emissions) and part 68 (network interconnection) and can therefore be sold in the U.S.A. It is not legal for use in Canada, however. It fails to meed the equivalent Canadian requirements. We have not tried any other countries, but it's an issue you ought to consider. -- Dave Levenson Westmark, Inc. The Man in the Mooney Warren, NJ USA {rutgers | att}!westmark!dave
David@cup.portal.com (07/25/88)
I'd recommend against using a V.22bis modem for international calls. The main reasons are that it isn't very fast (comparatively speaking) and is very susceptible to line noise. Look at V.32 modems instead. Although they are about 10x in price, they give you 4x the speed to reduce the cost of the calls, as well as being less susceptible to noise. So, you spend more up front, but you get it back many-fold over the course of time. David@cup.portal.com
peter@athena.mit.edu (Peter J Desnoyers) (07/27/88)
You might want to invest in a pair of good V.32 modems - any decent manufacturer should have them approved by European PTT's, and they are very resistant to errors. (The modulation scheme uses forward error correction) The problem is the price - $1500 to $4000. Real 9600bps is a plus, although I wouldn't pay for it out of my own pocket. In my biased opinion (I co-oped at Codex) the Codex V.32 is probably the best, but perhaps not worth the money. I'm sure it's approved in France. The UDS box performs almost as well, and was going for $1500 a while ago. I don't know if it is approved in France. Peter Desnoyers
henry@utzoo.uucp (Henry Spencer) (07/28/88)
In article <7651@cup.portal.com> David@cup.portal.com writes: >I'd recommend against using a V.22bis modem for international calls... >... it isn't very fast ... and is very susceptible to line noise. Look at >V.32 modems instead. ...10x in price... 4x the speed... less susceptible >to noise... Or Telebit Trailblazers, which are virtually immune to noise -- the only effect is that the throughput drops off -- and are likewise fast. The UUNET folks say that Trailblazers will run 6kbaud on phone lines that are virtually unusable for voice. Their one wart is that they can be a bit jerky for interactive work, although with the current firmware (4.00) this is occasionally annoying rather than seriously troubling. (Note that on the Trailblazer, unlike some of the V.nn modems, the drop in throughput with poorer lines is gradual rather than going in huge jumps.) -- MSDOS is not dead, it just | Henry Spencer at U of Toronto Zoology smells that way. | uunet!mnetor!utzoo!henry henry@zoo.toronto.edu
fs-info@sbsvax.UUCP (Fachschaft Mathe/Info) (07/29/88)
In article <1988Jul27.195804.20970@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > Or Telebit Trailblazers, which are virtually immune to noise -- the only > effect is that the throughput drops off -- and are likewise fast. At the CeBIT computer fair in Hannover I saw a connection from Germany to Canada with Trailblazers. They achieved more than 17,000 bits/sec. In Germany this is illegal. The maximum legal speed is 2,400 bits/sec, but only with ZZF-approved modems ( the ZZF is our "FCC" ; a ZZF 2.4Kbd modem costs about 2000 DM ). Most people here use unapproved(=illegal) modems. I think in France its similiar. ___ UUCP : fs-info@sbsvax.uucp /\/> / / / Phone: ++49-6805-8299 / / __ __`< o __ /- __ __ _ __ o _ /_ Snail: Hangweg 9 / /_(_/_/(_/_(_/ ( <___//(_//(_(/_/(_(_(_/ ( D-6601 Buebingen Z-Net : M.Emmerich@ums.zer Fido : 2:507/115
David@cup.portal.com (07/30/88)
henry@utzoo.uucp (Henry Spencer) wrote: >In article <7651@cup.portal.com> David@cup.portal.com writes: >>I'd recommend against using a V.22bis modem for international calls... >>... it isn't very fast ... and is very susceptible to line noise. Look at >>V.32 modems instead. ...10x in price... 4x the speed... less susceptible >>to noise... > >Or Telebit Trailblazers, which are virtually immune to noise -- the only >effect is that the throughput drops off -- and are likewise fast. The >UUNET folks say that Trailblazers will run 6kbaud on phone lines that are >virtually unusable for voice. No doubt about it, the Trailblazer is a nice modem. Having said that, I will now go on to say that it would take threats of a rather personal nature to get me to buy one. Why? Because the Trailblazer is quite definitely a non-standard product which only talks to other Trailblazers (excepting at 1200bps or whatever). When and if there are a dozen vendors making modems that work with the Trailblazer at high speed, then I'll buy it. In my opinion, the only good reason to buy a non-standard product is if you are able to toss it in the trash in a few years. Because usually by then it isn't supported by anyone, including the original vendor. I know that there are a lot of trailblazers used to connect the USENET sites, and that's fine for them, just not fine for me, because I hate tossing stuff in the trash in a year or two. David@cup.portal.com David McCord 415/424-5644
roy@phri.UUCP (Roy Smith) (07/31/88)
In article <7752@cup.portal.com> David@cup.portal.com writes: > In my opinion, the only good reason to buy a non-standard product is if > you are able to toss it in the trash in a few years. The original request was for info on unsupported modems to be used for a specific trans-Atlantic point-to-point dial-up link. Given the cost of trans-Atlantic phone calls, the savings you realize by even slightly better modems make it economical to buy the best you can now and toss them in a year or two if the winds of change make them no longer the best choice. -- Roy Smith, System Administrator Public Health Research Institute {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net "The connector is the network"
james@bigtex.uucp (James Van Artsdalen) (07/31/88)
In article <7752@cup.portal.com>, David@cup.portal.com wrote: > [..] Because the > Trailblazer is quite definitely a non-standard product which only talks to > other Trailblazers (excepting at 1200bps or whatever). When and if there > are a dozen vendors making modems that work with the Trailblazer at high > speed, then I'll buy it. Ventel makes a PEP modem, and I understand there are others with PEP products already on the market. > I know that there are a lot of trailblazers used to connect the USENET > sites, and that's fine for them, just not fine for me, because I hate > tossing stuff in the trash in a year or two. Standards are interesting things. I have never had anyone ask for a link with bigtex that couldn't talk to my TB+ at their fastest supported data rate (one site with a Hayes 2400 has some difficulty with PEP-tones-first). I have never asked anyone for a link and found that I couldn't talk to them at their highest supported data rate. There may be V.32, Hayes V9600 and US Robotics HST modems out there, but I haven't seen any sign of them around here. -- James R. Van Artsdalen ...!ut-sally!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746
jcb@loral.UUCP (Jay C. Bowden) (08/01/88)
In article <7752@cup.portal.com> David@cup.portal.com writes: >I know that there are a lot of trailblazers used to connect the USENET >sites, and that's fine for them, just not fine for me, because I hate ^^^^^^^^^^^^^^^ >tossing stuff in the trash in a year or two. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is going to sound critical, but that's OLD AGE THINKING! You're swimmin' up stream, baby, and stifling the economy, too! So maybe you can do without 19.2Kbps for a couple of years. That's fine, just wait, then. But it's not the people that fight for a place at the back of the line that make innovation happen! The trend is unarguably towards shorter product lifespans; look at your car for example! To me the key thing to look at here is why we think of this as "bad". I, for one, spend a fair amount of time consciously trying to force myself out of this mindset. Something to consider, anyway. > >David@cup.portal.com >David McCord >415/424-5644 - Jay (with an attitude) Bowden
rnv@motsj1.UUCP (Ron Voss) (08/02/88)
In article <576@sbsvax.UUCP>, fs-info@sbsvax.UUCP (Fachschaft Mathe/Info) writes: > At the CeBIT computer fair in Hannover I saw a connection from Germany to > Canada with Trailblazers. They achieved more than 17,000 bits/sec. > > In Germany this is illegal. The maximum legal speed is 2,400 bits/sec, but ^^^^^^^^^^^^^^^^^^^^^^^^^^ > only > with ZZF-approved modems ( the ZZF is our "FCC" ; a ZZF 2.4Kbd modem costs > about 2000 DM ). Most people here use unapproved(=illegal) modems. I think in > France its similiar. In Germany everything is illegal which is not explicitly allowed. Martin and all others involved in telecommunications in Germany should keep constant pressure on Blackpenny to abolish these stifling laws. There seems to be some progress: The Deutsche Bundespost indicates it will allow competition and will be more open-minded about advances in technology. It must if Germany is to compete in international telecommunications. -- Ron Voss Senior Systems Engineer Motorola Microcomputer Division 1150 Kifer Road, Sunnyvale, CA 94086, UUCP: {hplabs, mot, oakhill} !motsj1!rnv Telephone: +1 408-991-7390
david@infopro.UUCP (David Fiedler) (08/02/88)
> In article <7752@cup.portal.com>, David@cup.portal.com wrote: > [..] Because the > Trailblazer is quite definitely a non-standard product which only talks to > other Trailblazers (excepting at 1200bps or whatever). When and if there > are a dozen vendors making modems that work with the Trailblazer at high > speed, then I'll buy it. > One reason we bought a Telebit is that it is software-based. When and if the V.32 standard comes out, Telebit will simply sell upgrade ROMs at a reasonable price. If you have a hardware-based modem, you would have to throw it out at that point. The Telebit is also a de facto standard in the UNIX market at this point. If you're a PC user and want the cheapest possible high-speed modem, maybe something else makes sense -- but not if you're talking about UNIX. Why buy anything? Just wait 5 years for ISDN. Then all you have to do is get enough money to pay for the monthly connect charges... -- David Fiedler {ames,attmail,hoptoad,pyramid,spl1,ucdavis}!infopro!david USMail: InfoPro Systems, PO Box 220, Rescue CA 95672 Phone: 916/677-5870 "Never believe anything you read on Usenet"
david@ms.uky.edu (David Herron -- One of the vertebrae) (08/02/88)
In article <7752@cup.portal.com> David@cup.portal.com writes: >henry@utzoo.uucp (Henry Spencer) wrote: [Suggestion that V.22 modems are "too slow", to use V.32 modems instead, with a followup from Henry suggesting Trailblazers ...] >No doubt about it, the Trailblazer is a nice modem. > >Having said that, I will now go on to say that it would take threats of >a rather personal nature to get me to buy one. Why? Because the >Trailblazer is quite definitely a non-standard product which only talks to >other Trailblazers (excepting at 1200bps or whatever). When and if there >are a dozen vendors making modems that work with the Trailblazer at high >speed, then I'll buy it. Telebit is working on this. There is at least one other manufacturer which is building PEP modems (Ventel) and at least two manufacturers have been liscensed for PEP (I forget who the other manufacturer was). Also the standards organization is considering adopting PEP as an option to the V.32 standard. So, there will be some competition in the PEP field, and it will likely be accepted as a standard. In addition, look for Trailblazers to aquire V.32 capabilities, among other things. Someone at Telebit recently put out a survey asking us for features we'd like to have. This included V.32, FAX, SLIP, etc. V.32 came out very highly recommended ... Last fall when we ordered our Trailablazers for here I had no compunctions about it. There were reservations, but only to the extent that the product and/or company might not "survive" long enough to get to a point where they can add in V.32 & etc. Not that they would never add in V.32 & etc. I have also gone on and ordered one for myself (I got *real* spoiled when I tested the modems from home). >In my opinion, the only good reason to buy a non-standard product is if >you are able to toss it in the trash in a few years. Because usually by >then it isn't supported by anyone, including the original vendor. Good policy. I own a Sanyo Beta HI-FI VCR. I know from experience what it is like to own unsupported stuff. Trailblazers aren't likely to fall into that category however. -- <---- David Herron -- The E-Mail guy <david@ms.uky.edu> <---- ska: David le casse\*' {rutgers,uunet}!ukma!david, david@UKMA.BITNET <---- <---- Looking forward to a particularly blatant, talkative and period bikini ...
david@ms.uky.edu (David Herron -- One of the vertebrae) (08/02/88)
In article <1815@loral.UUCP> jcb@loral.UUCP (Jay C. Bowden) writes: >In article <7752@cup.portal.com> David@cup.portal.com writes: >>I know that there are a lot of trailblazers used to connect the USENET >>sites, and that's fine for them, just not fine for me, because I hate > ^^^^^^^^^^^^^^^ >>tossing stuff in the trash in a year or two. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >This is going to sound critical, but that's OLD AGE THINKING! You're >swimmin' up stream, baby, and stifling the economy, too! ... >The trend is unarguably towards shorter product lifespans; look at >your car for example! To me the key thing to look at here is why >we think of this as "bad". I, for one, spend a fair amount of time >consciously trying to force myself out of this mindset. Something >to consider, anyway. weee-eeell.. This is really straying from the beaten subject ... but I really hate this trend towards throwaway products. I really like being able to buy something and use it for 10 years or longer. Especially with something which so intensively uses raw materials like iron & copper, as a car does. To take some raw materials and cast them into some form takes time, energy and effort. Time is fairly cheap (depending on who is spending the time) but energy and effort is not cheap. (especially energy ... we need to be figuring out how to preserve energy rather than throwing it away). I equate throwing things away with throwing away the stuff which went into making the things. I spend a fair amount of time consciously trying to force myself out of the throwaway mindset. Something to consider, anyway. -- <---- David Herron -- The E-Mail guy <david@ms.uky.edu> <---- ska: David le casse\*' {rutgers,uunet}!ukma!david, david@UKMA.BITNET <---- <---- Looking forward to a particularly blatant, talkative and period bikini ...
rodd@dasys1.UUCP (Rod Dorman) (08/02/88)
>In Germany this is illegal. The maximum legal speed is 2,400 bits/sec ...
So what happens if you exceed 2400bps?
Does a cop on a megacycle pull you over?
-- Rod --
Rod Dorman {sun!hoptoad,cmcl2!phri}!dasys1!rodd
Big Electric Cat Public Unix
"The ships hung in the sky in much the same way that bricks don't"Ralf.Brown@B.GP.CS.CMU.EDU (08/02/88)
In article <55@infopro.UUCP>, david@infopro.UUCP (David Fiedler) writes: }One reason we bought a Telebit is that it is software-based. When and }if the V.32 standard comes out, Telebit will simply sell upgrade ROMs at }a reasonable price. If you have a hardware-based modem, you would have }to throw it out at that point. I think most modems nowadays are software-based (i.e. a CPU + an EPROM). Certainly the USRobotics HST and "desktalk ][" (actually an Incomm) are. Considering that Z80's sell for something like 40 cents in quantity, and EPROMs for a buck or so, it's probably a lot cheaper than hardwiring things, anyway. -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/31 Disclaimer? I |Ducharm's Axiom: If you view your problem closely enough claimed something?| you will recognize yourself as part of the problem.
chip@ateng.UUCP (Chip Salzenberg) (08/03/88)
According to fs-info@sbsvax.UUCP (Fachschaft Mathe/Info):
>In Germany this is illegal. The maximum legal speed is 2,400 bits/sec...
Oh, that's rich. There's no speed limit on the Autobahn, where people are
killed every week; but you can't move your data faster than 2,400 bps.
Lovely.
--
Chip Salzenberg <chip@ateng.uu.net> or <uunet!ateng!chip>
A T Engineering My employer may or may not agree with me.
You make me wanna break the laws of time and space
You make me wanna eat porkdomo@riddle.UUCP (Dominic Dunlop) (08/03/88)
In article <6435@bloom-beacon.MIT.EDU> peter@athena.mit.edu (Peter J Desnoyers) writes: >You might want to invest in a pair of good V.32 modems - any decent >manufacturer should have them approved by European PTT's, and they are >very resistant to errors. (The modulation scheme uses forward error >correction) The problem is the price - $1500 to $4000. Real 9600bps is >a plus, although I wouldn't pay for it out of my own pocket. Byte, June 1988, carries a comprehensive review of thirteen high-speed modems which can operate over the public telephone network. And, yes, the true V.32 products (as opposed to cut-down V.32, the older V.29, or proprietary) came out with the highest throughput in a random data test. Of the two full V.32 models tested, Telenetics 9600E/V.32 averaged 8995 bps on a clean connection, but failed completely on a simulated marginal connection; the Concord 296 Trellis did 8842 bps on a clean line, falling to 8237 on the bad line. By comparison, the much-discussed Telebit Trailblazer Plus did 5568 and 5078 bps respectively in each test. The joker in the pack was the Telcor Accelerator 2496MA which, by using very smart proprietary compression on top of old V.22 bis 2400 baud technology, achieved 8256 and 8362 bps. Yes, V.32 costs more: $1795 (or $1995 with data compression) for the Concord; $2295 for Telenetics. Neither of these modems supports any other protocol, so you can't call them up with your accoustic coupler. The Trailblazer lists at $1345, the Telcor at an amazing $895. Both these modems support all the common lower-speed protocols (if you're American, that is). You can get Trailblazers here in England from a company called Dowty. I don't know of an outlet for Telcor. Nor do I know about the situation in France. >In my biased opinion (I co-oped at Codex) the Codex V.32 is probably >the best... Byte didn't test the Codex. But it's a good article, anyway -- Dominic Dunlop domo@sphinx.co.uk domo@riddle.uucp
joel@peora.ccur.com (Joel Upchurch) (08/03/88)
In article <55@infopro.UUCP>, david@infopro.UUCP (David Fiedler) writes: }One reason we bought a Telebit is that it is software-based. When and }if the V.32 standard comes out, Telebit will simply sell upgrade ROMs at }a reasonable price. If you have a hardware-based modem, you would have }to throw it out at that point. I'm not that familar with modem technology , but wouldn't it be difficult to simulate the echo canceling circuitry that V.32 requires in software? -- Joel Upchurch/Concurrent Computer Corp/2486 Sand Lake Rd/Orlando, Fl 32809 joel@peora.ccur.com {cbosgd!codas,uiucuxc,hoptoad,petsd}!peora!joel (4078501040)
tron@mrecvax.UUCP (Carlos Mendioroz) (08/04/88)
This is just about telebit TrailBlazers Plus. We have a couple of them here that we use to contact uunet and pyramid for mail and news. The troughoutput is about 5kbps in the mean, with peeks at 8kbps but I wouldn't say they are inmune to noise or line conditions. We use uucp, g-protocol and no flow-control. In this configuration, they do the great job transmiting batched compressed news and are a little lazy when sending mail as uucp sends lots of litle files (control and data). May bsmtb help. Now for the odds. When we call early in the morning (say 3-5 am) they work fine but if we try to call during the day, we seldom get a nice result. Moreover, uucp almost everytime fails at startup (while establishing the g-protocol) or as the first file is being transmited. This all aplies to calls to uunet as the calls to pyramid seems to work all over the day. Carlos G. Mendioroz That plain.
garrett@udel.EDU (Joel Garrett) (08/05/88)
In article <791@riddle.UUCP> domo@riddle.UUCP (Dominic Dunlop) writes: [Discussion of "extensive" BYTE modem benchmarks deleted] >By comparison, the much-discussed Telebit >Trailblazer Plus did 5568 and 5078 bps respectively in each test. I think it was discussed here not long after that issue of BYTE came out that they were not very "real world", but then again, few benchmarks are. I think the biggest source of incorrect results for the TB+ in these tests were a result of 1) not fixing the interface speed at 19.2K bps 2) sending "random" data and thus not letting the modem's data compression stuff to work, and 3) Their definition of line noise for the test was evidently wide frequency spectrum noise, which would obviously blow away the PEP method of line compensation. The other thing that made me suspicious of the test was the different results obtained from the Ventel modem which was essentially the same modem in a different box. I know, same thing as always, no benchmark is totally accurate, special accomodations must be made sometimes, but most of the modems that they tested came with instructions to crank up the interface speed, etc for best performance, but I think they held the speed back because one or two of the units tested couldn't do it. Why not just make these exceptions a separate test and let the ones that can be in a different group, as they obviously are? >-- >Dominic Dunlop >domo@sphinx.co.uk domo@riddle.uucp Joel Garrett garrett@udel.edu
soley@ontenv.UUCP (Norman S. Soley) (08/05/88)
In article <7752@cup.portal.com>, David@cup.portal.com writes: > No doubt about it, the Trailblazer is a nice modem. > > Having said that, I will now go on to say that it would take threats of > a rather personal nature to get me to buy one. Why? Because the > Trailblazer is quite definitely a non-standard product which only talks to > other Trailblazers (excepting at 1200bps or whatever). When and if there > are a dozen vendors making modems that work with the Trailblazer at high > speed, then I'll buy it. > > In my opinion, the only good reason to buy a non-standard product is if > you are able to toss it in the trash in a few years. Because usually by > then it isn't supported by anyone, including the original vendor. > > I know that there are a lot of trailblazers used to connect the USENET > sites, and that's fine for them, just not fine for me, because I hate > tossing stuff in the trash in a year or two. Hmm... Seems to me that paying for itself in less than a year is a good enough reason to buy, so what if it's useless in 18 months, It's already more than paid for itself in saved long distance probably two or three times over. I worked it out, It's true if you move more than 20 Megs of data per month at full price for the modems, not counting the deals that Telebit is offering right now, based on LD calls not exceeding $.40 per minute the thing pays for itself in a year. What do you propose as an alternative? In this arena there simply are no standards yet (V.32, no matter what it looks like to your computer, is half duplex between modems). Will you wait until CCITT passes a standard for high speed full duplex modems? telebit has entered PEP into that sweepstakes and boy will you look the goat if they come out on top (you'll also get your wish because then Telebit would have to licence PEP or even give it away) -- Norman Soley - Data Communications Analyst - Ontario Ministry of the Environment UUCP: utgpu!ontmoh!------------\ VOICE: +1 416 323 2623 {attcan,utzoo}!lsuc!ncrcan!ontenv!norm "witty saying not available due to writers strike"
paul@cgh.UUCP (Paul Homchick) (08/05/88)
Regarding all of this talk about the Telebit Trailblazer Plus supporting
V.32: I was told by a Telebit saleman that the "current hardware
platform" cannot support, and consequently will never support V.32. If
this information is untrue, I am certain that someone from Telebit will
correct me, but until then, I shall assume that it is the case.
--
Paul Homchick UUCP: {allegra | rutgers | uunet} !cbmvax!cgh!paul
Chimitt Gilman Homchick, Inc.; One Radnor Station, Suite 300; Radnor, PA 19087ralf@b.gp.cs.cmu.edu (Ralf Brown) (08/05/88)
In article <648@ontenv.UUCP> soley@ontenv.UUCP (Norman S. Soley) writes: }In this arena there simply are no standards yet (V.32, no }matter what it looks like to your computer, is half duplex between }modems). No, V.29 is half duplex. V.32 is full duplex, 9600 bps each way. Which is why it requires such intricate echo-cancellation circuitry that the cheapest V.32 modems are >$1500, and most are $3000. The cheap 9600 bps modems such as the USRobotics HST all use V.29 with proprietary extensions for quick turnaround or a low-speed reverse channel. -- {harvard,uunet,ucbvax}!b.gp.cs.cmu.edu!ralf -=-=- AT&T: (412)268-3053 (school) ARPA: RALF@B.GP.CS.CMU.EDU |"Tolerance means excusing the mistakes others make. FIDO: Ralf Brown at 129/31 | Tact means not noticing them." --Arthur Schnitzler BITnet: RALF%B.GP.CS.CMU.EDU@CMUCCVMA -=-=- DISCLAIMER? I claimed something?
henry@utzoo.uucp (Henry Spencer) (08/06/88)
In article <3630@peora.ccur.com> joel@peora.ccur.com (Joel Upchurch) writes: >I'm not that familar with modem technology , but wouldn't it be difficult >to simulate the echo canceling circuitry that V.32 requires in software? Telebit's signal processors can do it in principle -- anything you can do in hardware can be done with digital signal processing software, in principle -- but as I recall, the Telebit folks doubt that the existing TB+ hardware has quite enough crunch to do it. A new model may be needed. -- MSDOS is not dead, it just | Henry Spencer at U of Toronto Zoology smells that way. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
soley@ontenv.UUCP (Norman S. Soley) (08/06/88)
In article <339@ateng.UUCP>, chip@ateng.UUCP (Chip Salzenberg) writes: > According to fs-info@sbsvax.UUCP (Fachschaft Mathe/Info): > >In Germany this is illegal. The maximum legal speed is 2,400 bits/sec... > > Oh, that's rich. There's no speed limit on the Autobahn, where people are > killed every week; but you can't move your data faster than 2,400 bps. > > Lovely. There is no "speed limit" as such. It's just illegal to use any modem not supplied by the Post Office and all they offer is 2400 Baud, hence a de facto speed limit. I know of one company that gets around this. Something about how the phone system can only detect a modem call when it originates, so there computers in Germany all get polled and don't call out, no way to get around the law between two points within Germany though. I'd rather take my chances on the Autobahn than on just about any North American highway. -- Norman Soley - Data Communications Analyst - Ontario Ministry of the Environment UUCP: utgpu!ontmoh!------------\ VOICE: +1 416 323 2623 {attcan,utzoo}!lsuc!ncrcan!ontenv!norm "witty saying not available due to writers strike"
dave@psbbs.UUCP (Dave Binette) (08/11/88)
Yesterday I had a chat with a fellow from W. Germany, who runs a FIDO node. He told me the max baud rate on BTX is 1200 baud. Apparantley the Gov. supplies the modems.
msurlich@immd1.informatik.uni-erlangen.de (Matthias Urlichs - scheme) (08/28/88)
In article <78@psbbs.UUCP> dave@.UUCP (Dave Binette) writes: >Yesterday I had a chat with a fellow from W. Germany, who runs a FIDO node. >He told me the max baud rate on BTX is 1200 baud. >Apparantley the Gov. supplies the modems. Well, in some bigger cities there is a 2400 baud entry. Of course you either have to buy an insanely expensive 2400 baud modem (>$600, non-hayes-compatible, no 300 baud) or carry your modem over and ignore the legal problems (hoping that they ignore you, too). The "normal" BTX entry is 1200 baud in and 75 baud out (at your place). What stumps me is whatever you want to do with BTX? There already are quite a few commercial mailbox systems here. However, for these the max speed still is 1200 baud (both ways). -- Matthias Urlichs CompuServe: 72437,1357 Delphi: URLICHS Rainwiesenweg 9 Phone: +49+911-574180 8501 Schwaig 2 NetMail: m_urlichs@msn.rmi.de West Germany or: (r)eply and (h)ope