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Sync speed drops when phone in use

AdamGayne
Newbie
Posts: 2
Registered: 06-12-2012

Sync speed drops when phone in use

Hi all,
I am experiencing a strange issue, that when our home phone is in use, my sync speed drops considerably. Once the call is ended, a reboot of the router will bring the sync speed back up to normal.
It only seems to have been happening since we returned from holiday on the 22nd November, during which my router was turned off for the 10 days we were away. I have had a problem previous to this where the sync would drop altogether when the phone was in use, and wouldn't re-sync until the phone was hung up - but this was intermittent, and wouldn't happen every time.
I am plugged directly into the master test socket, and there are NO OTHER sockets in the house, nor any extensions or other additional wiring. We have just this one phone in the house.
I have also changed the microfilter (I'm an IT tech, so have an abundance of these lying around!)
------------------------------------------------------------
Router: ZyXEL P-660HN-T1A
Stats (Current):
D/S Speed: 3275Kb/s
D/S Attenuation: 60.0 db
D/S SNR Margin: 9.9 db
U/S Speed: 864Kb/s
U/S Attenuation: 35.8 db
U/S SNR Margin: 8.9 db
BTW Line Test (Performed 21:45)
Download Speed: 2.68 Mbps
Upload Speed: 0.60 Mbps
Ping Latency: 46.88ms
Line Speed Shown In Member Centre:
Estimated line speed:
    Not recorded (service activated before we introduced estimates).
Current line speed:
    2.8 Mb
Stats (When phone in use):
D/S Speed: 165Kb/s
D/S Attenuation: 59.0 db
D/S SNR Margin: 8.0 db
U/S Speed: 864Kb/s
U/S Attenuation: 34.9 db
U/S SNR Margin: 7.5 db
BTW Line Test: Gave up waiting for the page to load!
------------------------------------------------------------
So as you can see, quite a considerable drop in downstream rate, but the upstream stays the same, with slightly better stats!! It might be worth noting that every time I've seen this happen, it has always dropped to 165Kb/s sync speed. Maybe this is the lowest my router will go?
As said, I'm an IT tech (albeit hardware/server support) so feel free to get technical, although I don't have an in depth understanding of ADSL!
Many thanks in advance
Adam
3 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Sync speed drops when phone in use

Obviously the effect of the phone ringing causes the line to drop and resyncs at a lower speed if that happens while you are on the call.
Can you try a few basic checks
Disconnect all the phones etc. and try ringing in from a mobile - does the line drop sync
If so - try the same thing while connected to the test socket - if that solves it you probably have an internal wiring problem
If it doesn't then you need to report a fault to Plusnet
If disconnecting all the phones etc. and ringing in doesn't cause a resync the problem may be a dodgy filter and if so try changing it or a dodgy phone
A process of elimination may point you in the right direction
Community Veteran
Posts: 4,852
Thanks: 121
Fixes: 24
Registered: 14-07-2009

Re: Sync speed drops when phone in use

You might like to read the comments on this thread I started http://community.plus.net/forum/index.php/topic,109634.0.html
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: Sync speed drops when phone in use

I think it might be worth distinguishing if there are any differences with incoming and outgoing calls. Jim has assumed this occurs when the phone rings, whereas your phraseology suggests it could be when you pick up the phone to make an outgoing call.
Is it a corded phone or a cordless? Did you change anything at all just before the previous problem occurred? Was the previous problem reported as a fault and repaired?
Can you hear/have you heard any crackling or other audible noise when using the phone? If need be, try the quiet line test 17070 options 2.
If it happens on an incoming call and an outgoing call it'll be best to just try another phone, but it seems likely to be a line or exchange fault.
If it happens with an incoming call but only when the phone is plugged in, again try another phone, but it's probably a line or exchange fault.