Difference between revisions of "Voice quality"
From Kolmisoft Wiki
Jump to navigationJump to search
| Line 34: | Line 34: | ||
= Providers with poor quality codecs = | = Providers with poor quality codecs = | ||
Do not use G723 and similar poor quality codecs with Providers. | Do not use G723.1, G726, GSM and similar poor quality codecs with Providers. | ||
In worst case use G729 - it has acceptable quality. | In worst case use G729 - it has acceptable quality. | ||
| Line 40: | Line 40: | ||
<br><br> | <br><br> | ||
= Poor internet connection with G711 codec = | = Poor internet connection with G711 codec = | ||
Revision as of 20:03, 19 August 2011
Introduction
Voice quality depends on:
- Network connection quality (jitter/delay/loss)
- Codecs
- Phones
Troubleshooting
- Change (soft)phone
- Check what codec device is using
- Change it to G729, retest
- Check network connection status using ping command from device's location to the server's location
- Make recording on the server with bad call, listen to it to decide which part sounds bad, localize in which part of the network problem is
- Check CLI for call log, look for line:
RTPAUDIOQOS: ssrc=1214214540;themssrc=2792486810;lp=0;rxjitter=0.000394;rxcount=1936;txjitter=0.000183;txcount=1975;rlp=0;rtt=0.000000
Check values lp and rlp, rxjitter and txjitter. If they > 0, means there are lost packets.
- lp means lost packets comming to device from the system
- rlp means lost packets comming from the device to the system
- rxjitter - jitter from the system to the device
- txjitter - jitter from the device to the system
More details: RTPAUDIOQOS Demystified
This information helps to determine quality issues in the connection between Device and the System.
Providers with poor quality codecs
Do not use G723.1, G726, GSM and similar poor quality codecs with Providers.
In worst case use G729 - it has acceptable quality.
Poor internet connection with G711 codec
When server is not in the same country as clients, and clients use phones/softphones without G729 support, such as eyeBeam, xLite and so on - then you will get poor voice quality.
This is because (soft)phones will use G711 codec, which will use 80 kbps connection.
In order to fix this problem, use only GSM and G729 codecs.
