DSL disconnecting during phone calls

keithoh · 08-09-2014 11:55AM #1

Hi Folks

Just wondering if anyone has experienced the following.

DSL connection is very stable SNR is around 9 to 11 db.

We have a Siemens C300 DECT Phone, and when we use the phone there is

alot of static on the line and in general the DSL connection will drop and I can

see that the SNR has now gone to anywhere from -0.5db to 3db.

We have had Eircom out and they have checked the line and said it is fine.

They replaced the main eircom socket with one of the new sockets with the filter built in.

After the socket replacement the line was fine for about 2 days, but now the problem is happenning again, could the DECT phone be adding noise to the line, or is this likely to be something else?

Should also say we are in a rural area, and as far as I know we are connected straight to the exchange

Thanks in advance for any advice

Keith

advertsfox · 08-09-2014 11:58AM

Are there filters on every phone point in your house? Have you a monitored house alarm? Sky connected to the phone?

keithoh · 08-09-2014 12:02PM

There's only the one phone point , and no monitored alarm. Sky box is not connected to phone line.

advertsfox · 08-09-2014 12:02PM

Can you post up your line statistics please?

keithoh · 08-09-2014 12:08PM

I'll post them up this evening, when I get home from work.

srsly78 · 08-09-2014 12:08PM

The built-in filter is not working it seems, get a new socket fitted.

keithoh · 08-09-2014 12:19PM

Hi srsly78

I'm not so sure that's the problem. Eircom just replaced the socket, and this was happenning with the old socket
we had before. I had tried different filters with the older socket but it never made any difference.

srsly78 · 08-09-2014 12:19PM

The wiring in your house is messed up so. Maybe you have an old disconnected line somewhere interfering.

keithoh · 08-09-2014 12:38PM

That's what I thought it might have been, but the phone socket in the house is connected to the cable from the pole outside our house and only has about a 7ft run internally in the attic cavity behind the wall where the phone socket is. Eircom have tested the line to this point and have said the line is fine.

I'm just trying to rule out any other issues there may be before I get eircom out again, that's why I'm wondering if the DECT phone could introduce that kind of noise onto the line or if it is on Eircoms side.

Thanks

Keith

ED E · 08-09-2014 12:44PM

Sounds very much like a dud handset to me....

When eircom go out the disconnect everything and test with their meter, then the modem. They dont typically connect all your equipment and run a test again from the MDF.

If the part of the board in your phone/phone base station that opens the circuit is faulty it could drop the sync. Change handset to test.

Aimeee · 08-09-2014 12:47PM

I'm having exact same problem but we are not with Eircom. We are with permaNET, internet phone.
Internet service is fine, I was thinking it's a handset problem.

keithoh · 08-09-2014 12:51PM

Thanks ED E

I'll see if the other handset is causing the same problem, it's not something I had been checking for.
I guess if both handsets are having the same problem I'll look into replacing the Base station

keithoh · 08-09-2014 07:42PM

advertsfox wrote: »

Can you post up your line statistics please?

I've included my line stats below

Connection
broadband: Connected
DSL Mode : ITU G.992.1(G.DMT)
Speed: 3072 kbps/384 kbps
Line Attenuation(Down/Up): 57.0 dB/ 31.5 dB
DSL Noise Margin: 10.0 dB/ 18.0 dB

Codpeas · 09-09-2014 03:44PM

Found an interesting thread somewhat related to this:

http://community.plus.net/forum/?topic=91605

Worth a read.

advertsfox · 09-09-2014 03:55PM

keithoh wrote: »

I've included my line stats below

Connection
broadband: Connected
DSL Mode : ITU G.992.1(G.DMT)
Speed: 3072 kbps/384 kbps
Line Attenuation(Down/Up): 57.0 dB/ 31.5 dB
DSL Noise Margin: 10.0 dB/ 18.0 dB

Well that makes more sense then. Your DECT phone could be putting some interference on the line, normally this wouldn't affect your connection but in your case with a 10dB noise margin (between 6 and 10 can be intermittent) and 57 dB attenuation (that's approx 6KM from your exchange), it's borderline stable so any interference could cause it to drop (also depending on your internal wiring condition).

A solution in this case, either change your phone or drop the profile to 2MB to stabilize the line (which will probably increase your noise margin to about 13dB+). Might I suggest you ask Eircom to drop your profile temporarily and see if you get any improvements? It only takes a minute to do and is easy switched. While you are at it, ask them to set it as high interleaving to improve it (higher error checking, more stable line in your case - gamers would want low interleaving since it decreases ping time).

ED E · 09-09-2014 04:03PM

advertsfox wrote: »

Well that makes more sense then. Your DECT phone could be putting some interference on the line, normally this wouldn't affect your connection but in your case with a 10dB noise margin (between 6 and 10 can be intermittent) and 57 dB attenuation (that's approx 6KM from your exchange), it's borderline stable so any interference could cause it to drop (also depending on your internal wiring condition).

A solution in this case, either change your phone or drop the profile to 2MB to stabilize the line (which will probably increase your noise margin to about 13dB+). Might I suggest you ask Eircom to drop your profile temporarily and see if you get any improvements? It only takes a minute to do and is easy switched. While you are at it, ask them to set it as high interleaving to improve it (higher error checking, more stable line in your case - gamers would want low interleaving since it decreases ping time).

Its more like 4.5km vs 6, and over 8dB is usually fine as long as the pair is in good condition. She shouldnt really need to drop down, that should be a last resort.

advertsfox · 09-09-2014 04:19PM

ED E wrote: »

Its more like 4.5km vs 6, and over 8dB is usually fine as long as the pair is in good condition. She shouldnt really need to drop down, that should be a last resort.

Should be a quick and easy troubleshooting step compared to getting a new phone. At least if that's not the issue, he can narrow it down to DECT phone / internal wiring.

keithoh · 09-09-2014 04:31PM

advertsfox wrote: »

Should be a quick and easy troubleshooting step compared to getting a new phone. At least if that's not the issue, he can narrow it down to DECT phone / internal wiring.

I managed to get hold of an old wired phone and connected that to the line and disconnected the modem. Once the call was initiated the line started to break up so I can rule out the DECT phone as the problem. Looks like the problem lies elsewhere

advertsfox · 09-09-2014 05:45PM

keithoh wrote: »

I managed to get hold of an old wired phone and connected that to the line and disconnected the modem. Once the call was initiated the line started to break up so I can rule out the DECT phone as the problem. Looks like the problem lies elsewhere

Could still be your internal wiring or a PSTN line fault. If you ring Eircom and report noise on the line when making phone calls with your router disconnected, they will log a PSTN fault with the wholesale team. Usual turnaround is 3-5 working days, often the technian will end up at your door to say its internal but since you already had someone out, odds are its an external issue.

lucernarian · 11-09-2014 04:41PM

One possibility is a fault with whatever filter they use in the exchange at the main distribution frame to separate signals going to the DSLAM and the voice switch. even if such a problem is extremely rare!

Failing that, perhaps the particular voice switch or the particular PSTN line card that serves you is faulty. More unlikely in my view but still possible is a fault with the line card in the DSLAM.

The fact that the problem isn't always there is confusing. Can you test the modem's connection over a few different times of day and night to see if there is a pattern? Or on different days?

For how long has this problem been popping up? Since the first day you got DSL installed or since you got the dect phone?

ED E · 11-09-2014 04:52PM

Im pretty sure there is no filtering between the AXE and DLSAM, that separation is done at the customer end.

keithoh · 11-09-2014 11:25PM

lucernarian wrote: »

The fact that the problem isn't always there is confusing. Can you test the modem's connection over a few different times of day and night to see if there is a pattern? Or on different days?

For how long has this problem been popping up? Since the first day you got DSL installed or since you got the dect phone?

The problem is there anytime we make a call. You can hear a hum while people are talking and then the line crackles at which point the DSL will lose sync. DSL is rock solid all day as long as no calls are made.

The problem started about 4 months and got really bad about a month ago. We got a txt message from Eircom yesterday to say the issue was fixed,so I figure they fixed something in the exchange as no one was out at the house or out on the road. The phone line was perfect for about 2 hours after we got the message and then started to crackle again midway through a call, and is now back on all calls.

I'm just going to have to keep reporting the fault till they get it fixed.

DSL disconnecting during phone calls

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