leonh@hhb.UUCP (leon howorth) (07/18/89)
I need to establish a UUCP connection with a site in the U.K. I have used my Telebit Trailblazer Plus for uucp within the U.S., but have never attempted the trans-atlantic connection. I have been told that the phone line quality for data transmission at that location is quite poor - such that their local data comm achieves 1200 bps at best. I would appreciate any advice, cautions, tips, etc. applicable to this situation. Thanks. Leon Howorth, HHB Systems, 201-848-8000 UUCP: ...princeton!hhb!leonh
bob@tinman.cis.ohio-state.edu (Bob Sutterfield) (07/18/89)
In article <265@hhb.UUCP> leonh@hhb.UUCP (leon howorth) writes:
I need to establish a UUCP connection with a site in the U.K... I
have been told that the phone line quality for data transmission at
that location is quite poor - such that their local data comm
achieves 1200 bps at best.
A site in the Netherlands gets anywhere from 491-556 bytes/sec,
usually in the 530s, when getting 100,000-byte files from us. An 8K
burst went at 1449 bytes/sec, but I suspect modem caching helped there
and fooled the UUCP logging mechanism into an optimistic report.
Trailblazers are legendary for squeezing the last bit of bandwidth
juice from the worst imaginable lines. They've been reported to
deliver good performance from Quito, Ecuador to Miami, Florida.
They'll probably do you good across the Pond, too, perhaps limited
most by the local telephone vagaries.henry@utzoo.uucp (Henry Spencer) (07/19/89)
In article <BOB.89Jul18094133@tinman.cis.ohio-state.edu> Bob Sutterfield <bob@cis.ohio-state.edu> writes: >> I need to establish a UUCP connection with a site in the U.K... > >Trailblazers are legendary for squeezing the last bit of bandwidth >juice from the worst imaginable lines. They've been reported to >deliver good performance from Quito, Ecuador to Miami, Florida. >They'll probably do you good across the Pond, too, perhaps limited >most by the local telephone vagaries. I seem to recall Rick Adams saying that London, England is the one place on Earth that even a Trailblazer can't connect to reliably. They will deliver 4-5kbps dependably in India, where local calls at 300 baud are impossibly unreliable (!), but not in London. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
roy@phri.UUCP (Roy Smith) (07/21/89)
> Trailblazers are legendary for squeezing the last bit of bandwidth juice > from the worst imaginable lines. They've been reported to deliver good > performance from Quito, Ecuador to Miami, Florida. I'll add another data point. Cuernavaca, Mexico to New York City. The Mexican phone system doesn't seem to have discovered echo supressors (it takes a lot of concious effort to carry on a voice conversation when you hear yourself 1/4 second after you say something). The blazers don't seem to notice. Microcomm SX-9624s (I think that's the right part number) with MNP level 5 could barely keep a connection open. -- Roy Smith, Public Health Research Institute 455 First Avenue, New York, NY 10016 {att,philabs,cmcl2,rutgers,hombre}!phri!roy -or- roy@alanine.phri.nyu.edu "The connector is the network"
grr@cbmvax.UUCP (George Robbins) (07/21/89)
In article <1989Jul19.160009.18318@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: > In article <BOB.89Jul18094133@tinman.cis.ohio-state.edu> Bob Sutterfield <bob@cis.ohio-state.edu> writes: > >> I need to establish a UUCP connection with a site in the U.K... > > > >Trailblazers are legendary for squeezing the last bit of bandwidth > >juice from the worst imaginable lines... > I seem to recall Rick Adams saying that London, England is the one place > on Earth that even a Trailblazer can't connect to reliably. They will > deliver 4-5kbps dependably in India, where local calls at 300 baud are > impossibly unreliable (!), but not in London. One might also might want to take note of the discussion here a while back about some settings that disabled short packets or something like that, allegedly making the TB+ work reasonably well over some kinds of international connection where they had previously failed... I think Rick's London comments preceeded these "discoveries" so perhaps there is some hope for such sad parts of the universe. Here are some extracted high point: ' >From: jbayer@ispi.UUCP (Jonathan Bayer) ' Date: 26 Mar 89 17:09:53 GMT ' In article <729@impch.UUCP> patg@impch.UUCP (Patrick Guelat) writes: ' > ' >I think there is an undocumented register in v4.0 of the firmware, that allows ' >you to disable the little packets (the ones for interactive use). As far as I ' >can remeber it's register 120 that allows you to set different packet modes. ' >Possibly you have to set 120=2 to allow long packets only, but I'm not ' >sure.. Perhaps telebit can answer this and tell us if there are other ' >undocumented registers. ' ' I was recently talking with Bob Boynton at Telebit, and the subject of ' my problems connecting with UUNET over the 800 lines came up. He ' described register s120, and suggested I try setting it to 2. I did, ' and all my problems went away. I have included a short description of ' the register below. It is a bit-mapped register, and using other values ' won't do anything. Bob said that using a value of 2 might come up with ' a net loss of about 15% throughput, however I have not noticed any ' reduction. ' ' s120= 0 when modems connect, and exchange info, will attempt to ' connect at the shortest possible packet ' 12 forces modem to abondon micropacket (faster on long ' distance lines) ' 2 long packets ' ' ' A suggestion he suggested was to turning the speaker on at all times ' (atm2). If you hear a lot of retrains (period of silence followed by ' re-syncing sound heard upon initial connect) then try setting s120=2. ' ' ' ' ============================================================================= ' ' Reply-To: pete@octopus.UUCP (Pete Holzmann) ' ' Rather than try more homebrew solutions, I actually called Telebit product ' support yesterday. Here's what they said (and the remaining questions I ' will call back for today, and post a second message with the answers): ' ' 1) No need to go back to rev 3.0. The new 'micropackets' in the 4.0 ROMs ' can cause havoc on low quality connections. Setting S120=12 disables ' micropackets and makes your connection look just like rev 3.0. If that ' isn't enough, go to S120=2, which also disables short packets, leaving ' you just 'long' packets. That will make interactive response terrible, ' but should make things happier for file transfers. ' ' 2) It turns out that the retrains-leading-to-connection-death syndrome is ' usually caused by the following: on an international connection, the ' first part of any burst of information is often chopped off by the ' phone connection (satellite echo cancellers? I don't know...). Normally, ' this would destroy the first part of a data packet. If too much of this ' happens, the modems will retrain. If it happens a LOT, they'll retrain ' a LOT, and eventually give up. To solve this, use the J6S36 register ' (that is NOT a typo: it is a hidden debug register...). The default ' value is 0. As you increase the value to 1,2, or 3, you cause an ' increasing period of "guard tone" to be inserted before each packet ' is sent. The guard tone gets chopped rather than your data, and you ' don't have any retrains any more. The guy I talked to suggested starting ' at J6S36=2, increasing to 3 if that doesn't help, decreasing to 1 if ' it works great (just in case you can get along with less tone). ' ' 3) If S120 is non-zero, it will show up in your ATN?. J6S36 will never show ' up. ' ' 4) From personal experiment, S120 *is* saved by AT&W. I have no easy way ' to tell whether J6S36 is saved. ' ' ============================================================================== ' ' >From: kunkee@ficc.uu.net (randy kunkee XNX MGR) ' Date: 24 Mar 89 04:38:41 GMT ' ' | 1) No need to go back to rev 3.0. The new 'micropackets' in the 4.0 ROMs ' | can cause havoc on low quality connections. Setting S120=12 disables ' | micropackets... ' | but should make things happier for file transfers. ' | ... ' | a LOT, and eventually give up. To solve this, use the J6S36 register ' | (that is NOT a typo: it is a hidden debug register...). The default ' | value is 0. As you increase the value to 1,2, or 3, you cause an ' | increasing period of "guard tone" to be inserted before each packet ' | ... ' | 3) If S120 is non-zero, it will show up in your ATN?. J6S36 will never show ' | up. ' | ... ' | ' | b) Must these parameters be used at both ends of the line? ' | ' ' No, not according to my conversations with Telebit. Set one end and the ' other follows suit. This makes a lot of sense. Just 'cause you can't ' do micropackets across a satellite is no reason to have to disable them for ' local phonecalls too. -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
csg@pyramid.pyramid.com (Carl S. Gutekunst) (08/27/89)
In article <1989Jul19.160009.18318@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >I seem to recall Rick Adams saying that London, England is the one place >on Earth that even a Trailblazer can't connect to reliably. I'll second it. We have absolutely dependable TrailBlazer links to Argentina, Chile, Italy, and Australia. And I hear of one company in Kuwait using UUCP and a TrailBlazer to upload data to their home office in Brussels. But the UK is no go. <csg>
steve@conch.UUCP (Steve Froeschke) (08/28/89)
In article <82193@pyramid.pyramid.com> csg@pyramid.pyramid.com (Carl S. Gutekunst) writes: >In article <1989Jul19.160009.18318@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >>I seem to recall Rick Adams saying that London, England is the one place >>on Earth that even a Trailblazer can't connect to reliably. > >I'll second it. We have absolutely dependable TrailBlazer links to Argentina, >Chile, Italy, and Australia. And I hear of one company in Kuwait using UUCP >and a TrailBlazer to upload data to their home office in Brussels. But the UK >is no go. > It only seems to affect systems IN London. I have a UUCP link with a system in Sandy UK (About 50 miles north of London), and I have no problems connecting/xfering with them. But I've tried a couple of systems in London itself, and its no go. I used to live in London (a little over a year ago), and found the lines in London to be noisy at best, unusable at worst. But if I dialed outside of London (outside of the 01 area code), I had no problems. I've no idea why that is, but there it is. Steve -- --------------------------------------------------------------------------- If it moves, Salute it, if it doesn't paint it gray and sail it! --------------------------------------------------------------------------- Steve Froeschke | uunet!conch!steve