UHF
All static, all day, Forever
Premium,MVM
join:2002-05-24
clubs:
 ·Qwest.net
 ·Callcentric
 ·surpasshosting
 ·Dish Network
·Future Nine Corpor..
| POTS line testing
This is fairly off-topic for this forum, but theres probably some guys here that can help me out.
At work we have remote video servers that use POTS lines with dial-in modems. We dial in over a modem in a PC once a day to look at the sites. One site stopped working all of a sudden. We connect, but no data transfers, and the modems disconnect.
We swapped out the server (with internal modem) so we've ruled that out. We've dialed in from dozens of other PC's remotely, so it's not an issue with the modems or phone lines at that end either.
Only thing left seems to be the phone line at that remote site. Telco (not Qwest in this case) says the line is fine, they "tested" it by listening for noise with the tech's ears and a butt set. The tech also dialed into the modem pool at the CO and that worked. At that point he told us it's our problem and left.
Aren't there tests they can do for SNR, attenuation, and things like that? If they do, what numbers should I see for a phone line that meets FCC specs?
Thanks for any help with this. It's driving me crazy. |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO
 ·Comcast
| Have you tried replacing the modem at the remote site? (Seems like you would have considering how through you have been, however it wasn't mentioned.)
--
"It's like a Zen koan - if you say something stupid, and no one is there to hear it, are you still an idiot?" -Mike Krahulik |
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UHF
All static, all day, Forever
Premium,MVM
join:2002-05-24
clubs: | Yes, it's internal to the server that we swapped out with another site. The problem remains with the site, not with the server/modem. Both servers work fine at another location. |
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AthlGrond
Premium,MVM
join:2002-04-25
Aurora, CO
·Comcast
| Ah, sorry I misunderstood, I thought that the remote sites were calling in to the server, not the server being at the remote site. (So... never mind.  )
--
"It's like a Zen koan - if you say something stupid, and no one is there to hear it, are you still an idiot?" -Mike Krahulik |
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AMD Phreak
Premium
join:2003-12-14
| reply to UHF
There are SNR tests that they can perform. I don't know what they should be for lines that are not provisioned as data circuits but there are minimum standards. If this were a leased-line dry pair they might work it a bit more (no, i am not talking about the naked-dsl type of dry pair). There are probably tests they can do such as blowing a tone down the line and measuring dB levels on the opposite end, but I cannot say for sure. I'll notify a tech and see if he can stop in here and comment.
--
"No job is so important, and no service is so urgent that we cannot take the time to do it safely."
-- AT&T
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--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it." |
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RockyBB
Premium
join:2005-01-31
Longmont, CO
| reply to UHF
have you tried ruling out the inside wire from the demarc to the device? maybe move the device closer to the demarc or use a different jack? maybe run some new cat 5 from the demarc to the device? are you running the line through a phone system? any changes in the building which might have touched the path from the demarc to the device? yah, it's probably Bell's problem, but if you can rule out the inside wire it will justify another dispatch... |
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no_one
@iauq.com
| reply to UHF
I do not know about your provider but when complete with work a full test is done. Never any guarantees on dial up speed but should work like a fully tested clean POTS pair. Does include tests like loss, SNR etc. A full automated test.
Though of course the ear is always good for the quick check along the way. Always a full test at the end even with POTS. Of course not the stricter standards of a data circuit. |
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no_one
@QWEST.NET
| reply to UHF
Basically there are specs for a POTS line from the old bell system. So all lines should be tested. If in the middle or=f nowhere a little high loss or some areas low inductive battery. But in general there are specs for a Pots line. The ear can be a very quick and easy first judge of a line and its problems. Though a complete test should be run when work is completed.
Some pair gain systems are not super friendly with dial up. But that should have been from day one.
Try a laptop taken to the site and dial up something.
If the tech dialed into a modem pool that does show it at least partially works. Though may have been trained at some ridiculously low speed. Most telcos do not guarantee dial up speeds but it usually should work reasonably well especially for remote equipment. May take 10 minutes to do something instead of 5 but it mostly should work.
Depending on the state highway departments use pots dial up on remote freeway, interstate signs. There is still a demand for dial up for remote equipment where not alot of data is being pushed and simple things need to be done. |
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UHF
All static, all day, Forever
Premium,MVM
join:2002-05-24
clubs:
·Qwest.net
·Callcentric
·surpasshosting
·Dish Network
·Future Nine Corpor..
| reply to UHF
Thanks for the tips. We finally got them to commit to doing a full test on the line. I hope it fixes it. I'm not even sure who the provider is, one of our other guys has been dealing with this problem and finally asked me what I thought after claiming the line was tested. After bugging him he told me that the "test" was the ear and the modem call from the remote site into a digital modem pool at the C.O. The local bell tech said that proves it works, unless something in the switch is bad, which he had no way to test and he wouldn't escalate the problem to the switching tech. I'm guessing it's some independent telco. |
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no_one
@QWEST.NET | reply to UHF
Yes it could be as abstract as the switch. But one modem pool at some low rate may not be what you are trying to train at. Could also be the other inside issues others have said. |
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Splitpair
Premium
join:2000-07-29
Cow Towne
 ·T-Mobile US
| reply to UHF
said by UHF  : After bugging him he told me that the "test" was the ear and the modem call from the remote site into a digital modem pool at the C.O. [/bqoute] I can do really well with a buttset but one cannot always clear a modem problem with one. More than likely since it once worked and now doesn't and given the fact you have swapped modems with a known worker it's a line problem. The tech needs to open the loop and do at the minimum a basic DC test and I would hope a balance test. [bqoute] The local bell tech said that proves it works, unless something in the switch is bad, which he had no way to test and he wouldn't escalate the problem to the switching tech. That only proves the line is capable of handling outgoing calls.
I'm guessing it's some independent telco. You might want to see if the service is provided by an ILEC or a CLEC. I have seen CLEC lines that simply will not handle dial-up data calls I believe due to the way they transport calls from the ILEC CO to their switch.
Wayne
--
If you cannot fix it with a buttset and some beanies you ain't a technician. |
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Splitpair
Premium
join:2000-07-29
Cow Towne
·T-Mobile US
| reply to no_one
said by no_one :
If in the middle or=f nowhere a little high loss or some areas low inductive battery. I think you mean high inductive noise which can be a problem anywhere one has long runs ajacent to power..
Some pair gain systems are not super friendly with ]
dial up. Universal pairgain should be able to support 14.4k and intergrated PG should support up to 33k.
Wayne
--
If you cannot fix it with a buttset and some beanies you ain't a technician. |
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