We have tried both analog PBX extensions (Avaya S8720s) and POTS lines for our AS/400 and retail data transfers to another locations and we have problems with both as the tranfer fails quite often. Switching between PBX extensions and POTS lines sometimes seems to help for a little bit (or coincidence) but does not seem to resolve the issues and the data guys swear it is due to line problems. Any suggestions? Should we try ordering conditioned POTS lines or conditioning testing but that does not explain it failing with the PBX extensions? Any suggestions on how to test/prove that the lines are okay? Thanks.
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Modem line data tranfer failing
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- Start date
Test your MOdem,if possible, over a Known working POTS line
once you know it is not your Modem you can be confident with other testing.
Have you tried swapping ports on your PABX(go to a different card to eliminate bad cards) in other words isolate sections of the line at a time to narrow down the possiblities of where the fault lies.
I have had faults like these come down to being caused by a different brand of patch cord, I.e. no fault found on testing and then the fault re-appearing after restoring the circuit.
BTW Phone Guys and Data Guys will always point the finger at the other.
This does sound like it is in the PABX but you need to check all of the circuit as ,as happens it may be a combination of factors.
This is why we call it FUN.
once you know it is not your Modem you can be confident with other testing.
Have you tried swapping ports on your PABX(go to a different card to eliminate bad cards) in other words isolate sections of the line at a time to narrow down the possiblities of where the fault lies.
I have had faults like these come down to being caused by a different brand of patch cord, I.e. no fault found on testing and then the fault re-appearing after restoring the circuit.
BTW Phone Guys and Data Guys will always point the finger at the other.
This does sound like it is in the PABX but you need to check all of the circuit as ,as happens it may be a combination of factors.
This is why we call it FUN.
OK, I'll throw in my 2 cents so you guys can all have a good laugh.... Aside from the obvious stuff (bad cross-connect, bad jack, bad line cord, bad serial cable, bad modem) here are a couple of other things to try - some of them may sound like they make no sense, but I've been playing with modems for a while....
Make sure the modem and its cables are away from the following: A digital telephone set, fluorescent lighting, the computer monitor, radio transmitters or cordless phones, the WiFi card or dongle of a PC or too close to the overhead antenna, and anything else that would give off a magnetic field or radio energy.
If the modem is inside your PC or system try to move it as far from the video card and/or system memory as possible.
And last, but not least, for everyone's amusement, on really bad lines I have successfully improved modem communications in the past by reversing the polarity on the phone line. I have no why idea why it would matter, as most of today's analog devices aren't all that polarity sensitive, but I have had situations where a modem that would only connect at 9600 at normal polarity was able to connect at 28.8 with reversed polarity.... your mileage may vary....
Make sure the modem and its cables are away from the following: A digital telephone set, fluorescent lighting, the computer monitor, radio transmitters or cordless phones, the WiFi card or dongle of a PC or too close to the overhead antenna, and anything else that would give off a magnetic field or radio energy.
If the modem is inside your PC or system try to move it as far from the video card and/or system memory as possible.
And last, but not least, for everyone's amusement, on really bad lines I have successfully improved modem communications in the past by reversing the polarity on the phone line. I have no why idea why it would matter, as most of today's analog devices aren't all that polarity sensitive, but I have had situations where a modem that would only connect at 9600 at normal polarity was able to connect at 28.8 with reversed polarity.... your mileage may vary....
Toni269
MIS
- Apr 18, 2002
- 815
Okay, a month ago the A/C failed down in "zee mud hole" where our CO equipment is located for our local phone provider. The room heated up over 140 degrees and damaged some equipment. I coulden't get any analog data to work - no fax, no modem. I called in the trouble ticket to the local provider and learned about the overheating from a gossipy tech and they replaced the T1 equipment at both ends for our local service T1's. It took about an hour of downtime for each. After that everything was A-Okay.
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- #8
Thanks. We have replaced the cable and cross-connect from the DMARC and the line sounds clean on a butt set. The modem has been replaced and is in an open rack on a shelf with other modems and is not near anything that should interfere with it. For the heck of it we will try flipping the cross-connect? We have called our provider about the POTS lines. The PBX extension has audible alerting turned off but we still have problems with both. We will keep trying. Thanks again. I welcome and appreciate any other suggestions you might have. Tom
While you have POTS lines they may be going through a line concentrator(as is common these days)some of them do give trouble for Data transmission.
I have a remote site for a PABX that i can talk to via modem from with in the site but once I am via the public network the extra MUX points and radio hops in this part of the line disconn the modem, the connections seem ok for voice
I have a remote site for a PABX that i can talk to via modem from with in the site but once I am via the public network the extra MUX points and radio hops in this part of the line disconn the modem, the connections seem ok for voice
I know we have had sites where they have used PairGains to mux multiple lines onto one pair, and those cause hell for analog lines that are connected to security systems. The line voltage fluctuates and causes the supervision circuit of the security system to report random trouble on the lines...
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