Don't forget things like jitter buffers, ECAN and tx/rx gains. All of these can be used to fine tune quality on calls, especially if the calls are terminating to a PSTN gateway. For instance on the Cisco 79XX IP phones dropping the microphone tx gain a couple of decibels (sometimes as much as -10db) can get rid of a lot of echo and on Sipura ATA's it makes other things such as G711 uLaw fax pass through more reliable.

-Evan

Edson wrote:

1.   QoS (shapping, priority, etc);
   
   

2.   Codecs (LPC10 (arghhh)? G723.1? ILBC? G729? Speex? GSM? G726?);
   
   

3.   Bandwidth (num_call * real_codec_bnad_required * 1,2_for_safity +
   

num_video * real_video_band * 1,1_for_safity + ..);

In this order.... ;)

Edson

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From: serusers-bounces@lists.iptel.org [mailto:serusers-bounces@lists.iptel.org] On Behalf Of Mike Cassidy Sent: quinta-feira, 29 de junho de 2006 15:34 To: serusers@lists.iptel.org Subject: [Serusers] Call quality

Can anyone point me in the right direction for resources that could help me to improve call quality? I have everything up and running ok, but the quality of the calls is a bit ropey at the moment. Any help here would be much appreciated.

Thanks in advance, Mike

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