Jump to content

This is the support site for Andrews & Arnold Ltd, a UK Internet provider. Information on these pages is generally for our customers but may be useful to others, enjoy!

SIP Audio Problems: Difference between revisions

m
 
(24 intermediate revisions by the same user not shown)
= Brief overview =
Here is a very brief overview of types of audio problems, their cause and the fix. This is not exhaustive, and usually there isn't a quick fix and diagnosing and investigation is required.
 
=== Types of problems that could be reported ===
* VoIP calls audio has echo echo
* VoIP calls are <big>too loud</big> or <small>too quiet</small>
* VoIP calls sound like they are under water
* VoIP calls are silent
* Audio starts out ok, but stops after a few seconds or a few minutes
* Audio has gaps, missing words
 
==General direction to take with different types of audio problem:==
 
{| class="wikitable"
|+ SIP Audio Problems, quick fixes or things to do
|-
! Type !! Typical Cause !! Typical fix
| '''No audio after a few minutes''' || Firewall/NAT/session timeouts || Investigate firewall/NAT/ALG
|}
 
 
* Calling *100 will play a continuous 1Khz tone - if the audio breaks up then there is a problem
 
== Audio transportation ==
 
The cause of an audio problem needs to be determined, especially if it's intermittent or only in one direction.
 
This diagram shows the possible places (each arrow) that could affect audio on a call.
 
[[File:Voip-audio.drawio.png|800px|frameless]]
 
The checks and questions outlined below go to some length to try to pinpoint which step is introducing the audio problem.
 
=== A&A Recordings ===
 
A&A Call recording can narrow down the cause of the problem, as it captures the audio part way through the path. This can tell if we are receiving bad audio from either party or not and so is a good way to narrow down the cause of the problem.
 
[[File:Voip-audio-recording.drawio.png|800px|frameless]]
 
= Checklist: =
|-
| '''If problem is outbound...''' || A&A Support can provide details on how to test making calls via the different upstream carriers that we use
|-
| '''What has changed recently?''' || eg, phone or pbx software upgrade, new broadband router, new ISP, new phone etc...
|}
 
=== A Checklist: ===
 
When investigating audio problems, especially if it's only on some calls and in one direction, it may be useful to go through a list of call types and describe what happens on each call for each person on either end of the call.
 
This table may help in these cases, make test calls and fill in the yellow boxes.
 
{| class="wikitable"
|+ Table of questions and test calls to try
|-
!
!
!
!
!
|-
| style="font-weight:bold;" | General Questions
| When did this start?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Describe the general problem
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Is it every single call that has the problem?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Can the problem be reproduced on demand?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Who is the internet provider?<br />
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Does calling *100 give a constant tone?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| Has a different phone/softphone be tried?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| What is the internet router being used?
| colspan="3" style="background-color:#ffffc7;" |
|-
|
| colspan="3" | ping voicelesss.aa.net.uk -c 1000
| style="background-color:#ffffc7;" | send results to A&A support
|-
|
| colspan="3" | mtr --aslookup --show-ips -o LA --report-cycles 1 --report-wide voiceless.aa.net.uk
| style="background-color:#ffffc7;" | send results to A&A support
|-
| style="font-weight:bold;" | Test calls to make:
|
|
|
|
|- style="font-weight:bold;"
| style="font-weight:normal;" |
| style="font-weight:normal;" |
| Is it OK?
| If not, describe problem
| Describe what's heard on the call recording
|-
| An incoming call from a mobile to the A&A Service<br />
|
|
|
|
|-
|
| Audio from the mobile
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
|
| Audio to the mobile
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
| An outgoing call to a mobile
|
|
|
|
|-
|
| Audio from the mobile
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
|
| Audio to the mobile
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
| An incoming call from a 'land line' to the A&A Service
|
|
|
|
|-
|
| Audio from the landline
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
|
| Audio to the landline
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
| An incoming call from the A&A Office
|
|
|
|
|-
|
| Audio from the office
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|-
|
| Audio to the office
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
| style="background-color:#ffffc7;" |
|}
 
== Things to investigate ==
 
* Check the quality of the internet connection
When did the problem start? - what changed around that time?
* Was phone system upgraded?
* Was the telephone software upgrades?
* Was the internet connection changed?
* Was the internet router changed?
* etc
 
Then:
 
* Check the quality of the internet connection - broken audio can be down to a poor internet connection
* Calling *100 will play a continuous 1Khz tone - if the audio breaks up then there is a problem
* Check the CQM graph (if using A&A for the internet connection)
autoreview, Bureaucrats, editor, Interface administrators, reviewer, Administrators
12,548

edits