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VOIP Quality suddenly gone downhill

philwelbourn
Member

We have a remote office that has for the last year or so enjoyed excellent VOIP calls - both directly into the main office VOIP number and elsewhere too. Suddenly it has become unusable producing what can only be described as sub-par AM radio type audio with very low volume. The other person can hear the converstaion fine - only the remote office has the quality issue - so I suspect its something to do with that VOIP account only or equipment at the those premises.

 

Any ideas, anyone?

 

Many thanks

13 REPLIES 13

SeanC
Master User

Hi Phil

 

Can you please tell me what the setup is and the equipment being used?

 

also has anything been installed or moved ie router moved over near a power supply

 

SC

gs
Super User

As per SC's suggestion, I suspect EMI also.

 

Move the router and power supply away from all other electrical equipment, especially ensure the cables are moved away also. Try and plug the phone and hub into their own power sockets without loads of other things connected and if possible use a surge protector.

philwelbourn
Member

Sorry for the late response. Standard BTbusiness Hub 2700 (2-wire). Standard wired handset plugged into VOIP port.

 

Only other symptom that may be relevant is that there is a small 'lag' when browsing websites - checked with support that correct DNS are being used and that bandwidth on connection is sufficient - all is ok. could a DNS issue affect VOIP - I suspect not??

 

Many thanks

gs
Super User

The voip sip servers are listed as domain names inside the router, so a DNS issue could cause this problem.

 

Can you try making VoIP calls on time during the day with nothing else connected to the router? You may be using too much bandwidth locally and that is effecting the service.

Chazza
Member

My VOIP has been unusable for the last 2-3 weeks, for the same reason.  Quality outgoing from me is fine, but incoming is suffering severe packet loss to the extent that the audio is completely garbled.

 

When I run online tests for packet loss and jitter, they come back showing a loss of incoming packets of anything between 70% and 88%, so it's not surprising it doesn't sound good!

 

I'm tearing my hair out trying to get someone at BT to look into it.  All they will do is test for speed, and that's healthy.  I have a download speed of around 6.8meg, which is great, but the packet loss is a drastic problem.  The online tests all point to one of a group of BT infrastructure servers as the place where the loss is occurring.  

 

What I really need is a BT Networks person to have a look at the route trace, but I can't work out a method of getting that done.  Anyone got any ideas?

gs
Super User

My recommendation -

 

Get data, get proof.

 

Do me a favor and click start, run, type cmd, press enter, then type pathping pingtest.bt.net and press enter.

 

It will take 5 mins to run, it will ping each individual hop on the way to BT's servers 100 times and calculate loss.

 

Once its run, right click in the window and go to edit then select all, right click again and go to edit then copy.

 

Paste the results in here and I will have a look and see whats going on.

 

If you have one hop that is dropping data, but all susequent ones are fine then its not an issue, the server will have some form of ICMP protection to prevent DDOS attacks, if one hop drops, and all hops do the same then we have an issue.

 

Also, try pathping www.google.co.uk

 

So we have 1 result thats all in the BT network, one that goes outside the BT Network.

 

gs

Chazza
Member

Thanks!

 

I've run 2 pathpings to BT and 2 to Google.  Results as follows:

 

pathping pingtest.bt.net

Tracing route to pingtest.bt.net [62.6.196.88]
over a maximum of 30 hops:
  0  Office.***.local [192.168.1.3]
  1  192.168.1.1
  2  host81-***-*-1.in-addr.btopenworld.com [81.***.*.1]
  3  213.120.178.141
  4  213.120.177.98
  5  213.120.176.26
  6     *        *        *
Computing statistics for 150 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           Office.***.local [192.168.1.3]

                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.1.1
                                0/ 100 =  0%   |
  2   27ms     0/ 100 =  0%     0/ 100 =  0%  host81-***-*-1.in-addr.btopenworld
.com [81.***.*.1]
                                0/ 100 =  0%   |
  3  ---     100/ 100 =100%   100/ 100 =100%  213.120.178.141
                                0/ 100 =  0%   |
  4   28ms     0/ 100 =  0%     0/ 100 =  0%  213.120.177.98
                              100/ 100 =100%   |
  5  ---     100/ 100 =100%     0/ 100 =  0%  213.120.176.26
                                0/ 100 =  0%   |
  6  ---     100/ 100 =100%     0/ 100 =  0%  Office6.***.local [0.0.0.0]

Trace complete.

 

xxxxx

 

pathping pingtest.bt.net

Tracing route to pingtest.bt.net [62.6.196.88]
over a maximum of 30 hops:
  0  Office.***.local [192.168.1.3]
  1  192.168.1.1
  2  host81-***-*.1in-addr.btopenworld.com [81.***.*.1]
  3  213.120.178.141
  4  213.120.177.98
  5  213.120.176.26
  6  213.120.176.178
  7  81.147.49.13
  8  core1-gig1-0-0.faraday.ukcore.bt.net [194.72.4.177]
  9  core1-pos8-1.birmingham.ukcore.bt.net [62.172.103.122]
 10  access0.birmingham.fixed.bt.net [62.6.196.88]

Computing statistics for 250 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           Office.***.local [192.168.1.3]

                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.1.1
                                0/ 100 =  0%   |
  2   27ms     0/ 100 =  0%     0/ 100 =  0%  host81-***-*-1.in-addr.btopenworld
.com [81.***.*.1]
                                0/ 100 =  0%   |
  3   32ms     0/ 100 =  0%     0/ 100 =  0%  213.120.178.141
                                0/ 100 =  0%   |
  4   28ms     0/ 100 =  0%     0/ 100 =  0%  213.120.177.98
                                0/ 100 =  0%   |
  5  ---     100/ 100 =100%   100/ 100 =100%  213.120.176.26
                                0/ 100 =  0%   |
  6   28ms     0/ 100 =  0%     0/ 100 =  0%  213.120.176.178
                                0/ 100 =  0%   |
  7   28ms     0/ 100 =  0%     0/ 100 =  0%  81.147.49.13
                                0/ 100 =  0%   |
  8   28ms     0/ 100 =  0%     0/ 100 =  0%  core1-gig1-0-0.faraday.ukcore.bt.n
et [194.72.4.177]
                                0/ 100 =  0%   |
  9   34ms     1/ 100 =  1%     1/ 100 =  1%  core1-pos8-1.birmingham.ukcore.bt.
net [62.172.103.122]
                                0/ 100 =  0%   |
 10   34ms     0/ 100 =  0%     0/ 100 =  0%  access0.birmingham.fixed.bt.net [6
2.6.196.88]

Trace complete.

 

xxxxxxx

 

pathping www.google.co.uk

Tracing route to www-tmmdi.l.google.com [66.102.9.105]
over a maximum of 30 hops:
  0  Office*.***.local [192.168.1.3]
  1  192.168.1.1
  2  host81-*-*-1.in-addr.btopenworld.com [81.***.*.1]
  3  213.120.178.141
  4  213.120.177.98
  5  213.120.176.26
  6     *        *        *
Computing statistics for 150 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           Office.***.local [192.168.1.3]

                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.1.1
                                0/ 100 =  0%   |
  2   27ms     0/ 100 =  0%     0/ 100 =  0%  host81-***-*-1.in-addr.btopenworld
.com [81.***.*.1]
                                0/ 100 =  0%   |
  3  ---     100/ 100 =100%   100/ 100 =100%  213.120.178.141
                                0/ 100 =  0%   |
  4   29ms     0/ 100 =  0%     0/ 100 =  0%  213.120.177.98
                              100/ 100 =100%   |
  5  ---     100/ 100 =100%     0/ 100 =  0%  213.120.176.26
                                0/ 100 =  0%   |
  6  ---     100/ 100 =100%     0/ 100 =  0%  Office.***.local [0.0.0.0]

Trace complete.

 

xxxxxxxx


pathping www.google.co.uk

Tracing route to www-tmmdi.l.google.com [66.102.9.105]
over a maximum of 30 hops:
  0  Office.***.local [192.168.1.3]
  1  192.168.1.1
  2  host81-***-*-1.in-addr.btopenworld.com [81.***.*.1]
  3  213.120.178.141
  4  213.120.177.98
  5  213.120.176.26
  6     *        *     213.120.176.178
  7  213.120.176.117
  8  core1-gig1-0-0.faraday.ukcore.bt.net [194.72.4.177]
  9  62.172.103.33
 10  core4te-0-3-0-0.telehouse.ukcore.bt.net [62.172.102.17]
 11  195.99.125.82
 12  209.85.255.175
 13  209.85.251.190
 14  64.233.174.187
 15  64.233.174.14
 16  lm-in-f105.1e100.net [66.102.9.105]

Computing statistics for 400 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           Office.***.local [192.168.1.3]

                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.1.1
                                0/ 100 =  0%   |
  2   27ms     0/ 100 =  0%     0/ 100 =  0%  host81-***-*-1.in-addr.btopenworld
.com [81.***.*.1]
                                0/ 100 =  0%   |
  3   28ms     0/ 100 =  0%     0/ 100 =  0%  213.120.178.141
                                0/ 100 =  0%   |
  4   27ms     0/ 100 =  0%     0/ 100 =  0%  213.120.177.98
                                0/ 100 =  0%   |
  5  ---     100/ 100 =100%   100/ 100 =100%  213.120.176.26
                                0/ 100 =  0%   |
  6   28ms     0/ 100 =  0%     0/ 100 =  0%  213.120.176.178
                                0/ 100 =  0%   |
  7   29ms     0/ 100 =  0%     0/ 100 =  0%  213.120.176.117
                                0/ 100 =  0%   |
  8   28ms     0/ 100 =  0%     0/ 100 =  0%  core1-gig1-0-0.faraday.ukcore.bt.n
et [194.72.4.177]
                                0/ 100 =  0%   |
  9   29ms     1/ 100 =  1%     1/ 100 =  1%  62.172.103.33
                                0/ 100 =  0%   |
 10   29ms     0/ 100 =  0%     0/ 100 =  0%  core4te-0-3-0-0.telehouse.ukcore.b
t.net [62.172.102.17]
                                0/ 100 =  0%   |
 11   32ms     0/ 100 =  0%     0/ 100 =  0%  195.99.125.82
                                0/ 100 =  0%   |
 12   34ms     0/ 100 =  0%     0/ 100 =  0%  209.85.255.175
                                0/ 100 =  0%   |
 13   42ms     0/ 100 =  0%     0/ 100 =  0%  209.85.251.190
                                0/ 100 =  0%   |
 14   42ms     0/ 100 =  0%     0/ 100 =  0%  64.233.174.187
                                0/ 100 =  0%   |
 15   46ms     0/ 100 =  0%     0/ 100 =  0%  64.233.174.14
                                0/ 100 =  0%   |
 16   42ms     0/ 100 =  0%     0/ 100 =  0%  lm-in-f105.1e100.net [66.102.9.105
]

Trace complete.

 

gs
Super User

Very strange... the tracert is going out up to hop 5 but then is looping back to localhost. Strange.

 

Are you using a static IP? If not, restart your router.

 

Also, do an ipconfig /all to check what your DNS servers are, are you using a pair of the following?

 

194.72.9.34 194.72.9.38
194.74.65.68 194.74.65.69
194.72.0.98 194.72.0.114
62.6.40.178 62.6.40.178

 

If not, try changing the router or your PC to use them and try again.

 

There is an issue with Register DNS going on right now that could be affecting this, when did it start happening?

Chazza
Member

Yes, we're using the first pair on that DNS list.

 

This all started about 3 weeks ago.  The issue was clouded by the fact that there was a physical line fault.  That led to an unstable connection and consequent loss of speed as the automatic profiler sought to stabilise things.  At first, BT could find no fault. Then they said a test had revealed a DNS fault.  At that point our router was set to obtain DNS servers automatically, but BT suggested I force it to a particular pair.

 

When that didn't resolve things, I began to suspect our router, so I replaced it with a spare but there was no improvement.  Then the tester suggested a Rectified Loop fault, so we had an engineer visit to track that down.  First visit found no fault, but a second visit the following day found a defective faceplate on the ADSL linebox.  That was changed, and the line tested clear. 

That seems to have got rid of the instability, and our download speed has been reset to the normal value of around 6.5

 

However, throughout all this, various online tests for packet loss have consistently shown a very high loss of packets incoming to us.

 

What would be the symptoms of the Register DNS problem you mention?   The symptoms I'm seeing here are:  (a)  unusable VOIP owing to missing packets; (b)  web pages generally load ok but quite often seem to be searching for a long time when they try to auto-refresh.