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inthedales
Aspiring Contributor
1,843 Views
Message 1 of 13

Please help, noisy phone line think its a high resistance fault.

HI,

 

Just moved in and phone line / bt broadband was activated a week ago.  Phone master socket is OpenReach branded.

 

I have the BT supplied broadband filter fitted directly to the test socket (just the adsl router and a single phone connected).

 

Using the 17070 quiet line test , i have varying volumes on hissing and noise on the phone. This varies between loud and intrusive (difficult to hear callers) to fairly quiet.  This seemed to be better during the cold weather over last weekend, but is worse again this morning.

 

I can also hear adsl connection noise when the router was connecting, depsite being through the adsl filters. This lead me to find threads related to High resistance faults whcih I think may apply to me.

 

BT online fault test shows no fault found.

 

 

Adsl Stats:

I was supplied with a home hub 3A

 

Connection Information

Line state: Connected
Connection time: 0 days, 21:29:11
Downstream: 3.625 Mbps
Upstream: 448 Kbps

ADSL Settings

VPI/VCI: 0/38
Type: PPPoA
Modulation: G.992.1 Annex A
Latency type: Interleaved
Noise margin (Down/Up): 10.6 dB / 15.0 dB
Line attenuation (Down/Up): 32.2 dB / 16.0 dB
Output power (Down/Up): 19.9 dBm / 12.4 dBm
FEC Events (Down/Up): 2941 / 325
CRC Events (Down/Up): 12 / 45
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
HEC Events (Down/Up): 79 / 30
Error Seconds (Local/Remote): 8 / 22


1. Product name: BT Home Hub
2. Serial number: 
3. Firmware version: Software version 4.7.5.1.83.8.57.1.3 (Type A) Last updated Unknown
4. Board version: BT Home Hub 3.0A
5. ADSL uptime: 0 days, 21:31:21
6. Bandwidth: 448 / 3712
7. Data sent/received: 0.3 / 2.7
8. Broadband username: bthomehub@btbroadband.com
9. BT FON: Yes
10. Wireless network/SSID: BTHub3-KC3K
11. Wireless connections: Enabled, (802.11 b/g/n (Recommended)) 20 MHz
12. Wireless security: WPA and WPA2
13. Wireless channel: Automatic / 1
14. Firewall: Default
15. MAC Address: 
16. VPI/VCI: 0 / 38
17. Line profile: Interleaved
18. Software variant: -
19. Boot loader: -

 

The home hub doesn't seem too good at keeping the sync, speed drops regularly and it maintains a high SNR.

 

My previous router was a Thomson Speedtouch 780, which provides a higher sync and much better stability. Presumably this is due to the broadcom chipset (would a home hub 3b also be better?)

 

Speedtouch stats from this morning:

---------------------------------------------------

speedtouch 4/12/12 08:45

DSL Connection

Link Information

Uptime: 1 day, 10:39:46

Modulation: G.992.1 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 5.120

Data Transferred (Sent/Received) [MB/MB]: 24,94 / 119,27

Output Power (Up/Down) [dBm]: 12,0 / 19,5

Line Attenuation (Up/Down) [dB]: 15,5 / 31,0

SN Margin (Up/Down) [dB]: 19,0 / 9,0

Vendor ID (Local/Remote): TMMB / TSTC

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 0 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 0 / 0

FEC Errors (Up/Down): 0 / 158.090

CRC Errors (Up/Down): 0 / 68

HEC Errors (Up/Down): 0 / 62

 

--------------------------------------------------------------

speedtouch 04/12/12 09:30

DSL Connection

Link Information

Uptime: 1 day, 11:25:26

Modulation: G.992.1 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 5.120

Data Transferred (Sent/Received) [MB/MB]: 28,90 / 129,91

Output Power (Up/Down) [dBm]: 12,0 / 19,5

Line Attenuation (Up/Down) [dB]: 15,5 / 31,0

SN Margin (Up/Down) [dB]: 19,0 / 4,5

Vendor ID (Local/Remote): TMMB / TSTC

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 0 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 0 / 0

FEC Errors (Up/Down): 0 / 171.051

CRC Errors (Up/Down): 0 / 68

HEC Errors (Up/Down): 0 / 62

 

As your can see theres a wide range in the SNR figures, although the speedtouch is much better at holding the sync and not dropping the speed.

 

Given the line attenuation at 31db, I would have expected a higher sync rate. The estimated line length of ~2.2km from kitz.co.uk seems to be about right.

 

Any advice appreciated, including how to report this fault to the right people.

 

Thanks

Jon

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12 REPLIES 12
Guru
1,839 Views
Message 2 of 13

Re: Please help, noisy phone line think its a high resistance fault.

The best thing to do is ring faults on 151 ... and register a very noisy phone line.

 

Fix the line ... and the broadband will look after itself.

 

 

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inthedales
Aspiring Contributor
1,833 Views
Message 3 of 13

Re: Please help, noisy phone line think its a high resistance fault.

Thanks, I have booked an engineer visit for next week. 

 

However my concern is that when the enginner visits the line noise will be quiet and he will not find a fault. If I unplug the the adsl entirely and just plug the phone into the test socket the line is generally quiet.  (I have tried numerous filters to ensure its not a faulty filter).

 

I'm worried the fault won't be found and I'll be charged for it.

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Guru
1,829 Views
Message 4 of 13

Re: Please help, noisy phone line think its a high resistance fault.

The engineer will do a full line test using a JDSU .... and if the line noise has been consistent but sometimes

 

sporadic tell him so, it may be it's worst in wet weather for example, you would know better. If that is the case he may

 

decide to put you on another pair if one exists rather than try to find the fault on your pair. (plant some seeds)

 

Also, while he is there, it may be benefitial if you ask him to fit you a SSFP, which gives the best broadband/phone

 

segregation possible, providing it fits in with your home network requirement. Clearly, if you do, the socket needs to be

 

placed in the best position for broadband use .... without running trailing cables around the place.   😉

 

And when he's finished, request a broadband line profile reset, as his intervention will undoubtedly cause some

 

linespeed problems, to begin with.

 

It's also worth noting, seeing as the connection is new, in all liklihood it's not likely to have finished line training, so ask

 

him when he requests the profile reset, if the connection can be set back to day 0, to start afresh, that way it'll train

 

again .... without line faults, and properly.   🙂

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Guru
1,812 Views
Message 5 of 13

Re: Please help, noisy phone line think its a high resistance fault.

By the way ... go back and delete the mac addresses of your hubs/routers .... they're a security risk on a public forum.
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inthedales
Aspiring Contributor
1,805 Views
Message 6 of 13

Re: Please help, noisy phone line think its a high resistance fault.

Thanks for the heads up.
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inthedales
Aspiring Contributor
1,740 Views
Message 7 of 13

Re: Please help, noisy phone line think its a high resistance fault.

Update:

 

I knew today wasn't going to be a good day, when i picked up the phone and quiet line test was actually quiet.

 

Engineer visited this morning.  Unplugged adsl filter from test socket etc. Didn't have mobile coverage so couldn't trigger tests in his usual way, used phone to call and get someone to run them remotely, phoned for results tests came back OK. Couldn't find a fault.

 

I explained the sporadic nature, how the noise varies, the fact that if it is noisy incoming calls seem to improve matters, how bad it was when first activated etc.  He said it must be a fault in my equipment, said he had tested on his way over and seen a fault but testing with the filter/phone unplugged showed no fault.

 

He then plugged some equipment connected to a laptop in, and after 8 or so attempts (he had to ring using the phone line then quickly disconnect and connect the test equipment) ran a line test to his laptop. From what I could see all showed green except 'leg resistance test' orange at 96.something %.  He showed me the bottom which showed passed.

 

So i'm left with the diaganosis its my equipment. I've tested in the master socket, used 3 phones, 3 adsl filters and 2 routers to rule out this possability. For now I have a useable working line but how long until the problem shows again.

 

Any advice appreciated.

 

 

 

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Distinguished Sage
1,730 Views
Message 8 of 13

Re: Please help, noisy phone line think its a high resistance fault.

All you can do is report it again and hope the engineer turns up when the fault is the
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inthedales
Aspiring Contributor
1,684 Views
Message 9 of 13

Re: Please help, noisy phone line think its a high resistance fault.

I'm suspecting that I will be getting billed for the last engineer visit ( as he couldn't find a fault and therefore said it must be my equipment). I can't afford to pay one fee let alone 2 if I report it again with the same result.

 

However since the visit, the occurrences of the intermittent noise on the line have been fewer and further between. This morning however, after listening to a 1571 message I heard more noise so I did a quiet line test to see. Initially the line was quiet, but then I heard some quit noise and then a ringing sound (like when you dial a number and it rings remotely) as if I had made a call. The "BT Quiet line message" cut in but I could still here the ringing underneath. I waited to see if I would be able to hear if someone answered but the ringing stopped after a while and I couldn't here a voice so I don't know if they answered or it rung off.

Is it possible my line is picking up the ring tone from another line?

 

Also, when the engineer arrived he initially said his test had shown a fault and that water must have got in somewhere. However when he removed my filter/phone/router from the test socket, his tests then showed no fault. Is it possible the fault only shows up when the adsl is active.  Back when the line was first active I could the router negotiating (even thorough 2 filters) although this doesn't happen now.

 

Moving on to the adsl side of things, Currently my stats are:

 

 

DSL Connection

Link Information

Uptime: 0 days, 11:48:54

Modulation: G.992.1 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 5.440

Data Transferred (Sent/Received) [MB/MB]: 9,61 / 39,04

Output Power (Up/Down) [dBm]: 12,0 / 19,5

Line Attenuation (Up/Down) [dB]: 15,5 / 31,0

SN Margin (Up/Down) [dB]: 20,0 / 5,0

Vendor ID (Local/Remote): TMMB / TSTC

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 0 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 0 / 0

FEC Errors (Up/Down): 0 / 1.384

CRC Errors (Up/Down): 0 / 0

HEC Errors (Up/Down): 0 / 0

Interleaved.

 

With the BT Home hub (3a) the connection would drop peridocally, so I'm using my Thomson 780wl which hold the connection better and also shows less FEC errors than the HH.

I think the connection speed and the interlacing are poor given the line attenuation. The line length is about 2 - 2.5km,  underground from the village to the exchange, overground to the house. No cabinets directly connected to exchange.

 

I've been monitoring signal to noise ratio and have noticed something odd:

 

NoiseMargin-2012Dec18-1001.jpg

 

This happens every day, in the same pattern.  Its not interference from any internal wiring or appliances or heating etc. I understand that noise changes over time but this is a 5+ DB drop is this normal?

 

Any advice?

 

 

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Guru
1,676 Views
Message 10 of 13

Re: Please help, noisy phone line think its a high resistance fault.

Two things are apparent here ...

 

Firstly the noise on the line could be dslam crosstalk .... which needs investigation, or if it is wet connections in a hole in the ground, likewise.

 

Secondly the drop in noise margin is definately not normal and shows an event or condition that needs attention.

 

Both ways, I feel you need to see a BT response again, so emai back in to the moderators, who will pick up the notes on the case file, and report these issues.  🙂

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