ULAW codec

[xCape]

Hello,

How do I use a .ulaw file instead of .gsm for outbound calls on a PRI zap channel?

Thank you.

[mcargile]

Asterisk does what is called transcoding where by it will take a sound file and convert it to the appropriate codec for the connection type. So it really does not matter.

That being said transcoding uses processing power so if you have the recording in the native format of the channel Asterisk is supposed to use that format to play back the sound. So the answer to your question is yes the best codec to use with a PRI is probably ulaw but others will work just as well.

[xCape]

Hello,

I want to use a .wav file in ulaw format for better audio quality. Right now the message we leave is choppy and has static. I have a call open to XO to check our lines but I was wondering if it would sound better with this wave file I have.

Here are my errors from the CLI:

Nov 25 14:10:44 WARNING[7228]: file.c:517 ast_openstream_full: File NAB_Betty_071408ulaw.wav does not exist in any format
Nov 25 14:10:44 WARNING[7228]: file.c:828 ast_streamfile: Unable to open NAB_Betty_071408ulaw.wav (format unknown): No such file or directory
Nov 25 14:10:44 WARNING[7228]: app_playback.c:133 playback_exec: ast_streamfile failed on Zap/1-1 for NAB_Betty_071408ulaw.wav

Thanks!

[mcargile]

your wav file is not in a format Asterisk understands. Windows wav files are actually standard wav files. The Asterisk Guru website has a sound file conversion tool you might try.

[xCape]

OK. I'm using a .ulaw file and the quality is more acceptable.

Thanks for your help.