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UCCX 7 audio prompts problem - sound distorted

mansssorange
Level 1
Level 1

Hi,

We have a UCCX 7 system which holds many IVR prompts, lately we added a new audio prompt to be played if users are waiting in the queue of the IVR.

The prompt is being played normally but at some points of the prompt the sound is a little distorted, it is a music ad, and when the music gets high the sound is some how distored which is not accepted by our management.

The file specifications are like the rest of the prompts which is::

1. Bit Rate= 64kbps
2. Audio sample size= 8 bit
3. Channels = 1 (mono)
4. Audio sample rate = 8khz
5. Audio format = u-law

The codecs of the prompts is G.711.

Apreciate any assistance please, thanks a lot.

2 Accepted Solutions

Accepted Solutions

Can you describe a little more about which parts of the prompt are being distorted?

Another possibility is that if your media stream is being put through a transcoder - i.e. the server is running G711, but being trancoded intentionally or not on the way to your gateway/phone. G729 is designed to compress voice, so if you run music through it it ALWAYS sounds terrible.

If you have music that sounds bad, and voice that sounds OK, then that could be your problem. Try verifying what codec is actaully in use (e.g. from your desk phone you can press ? twice quickly to see which codec is in use when a call is active).

Aaron

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

View solution in original post

Hi

No, if you run G729 you will get poor quality music. It's just a function of the way that G729 works.

The option you mentioned makes UCCX run G729 prompts natively - if all communications to/from the UCCX server need to run G729, there's no point sending them out at g711 and having to transcode everyting. Conversely if you mainly use G711, you would have UCCX run G711 prompts so that you don't lose audio quality for no good reason.

If you need good quality, then you can do one of these two things IF your music is just played in between the prompts. If you have prompts created with background music embedded in it then you can't do this:

1) stream the music as G711 from CallManager by ensuring the MoH server is in a region that allows g711 between it and your PSTN gateways on the remote site

2) stream the music as G711 from the local gateway using multicast; there are lots of references on how to do this on this forum and on cisco.com.

If you have background music mixed in with the voice in your prompts, and you need good quality then your only real option is to stop using G729, or start again with voice-only prompts and an MoH solution as suggested above.

Regards

Aaron

Please rate helpful posts and mark answered questions that you've got a satisfactory response from to help identify useful content in the forums...
https://supportforums.cisco.com/docs/DOC-6212

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

View solution in original post

9 Replies 9

Aaron Harrison
VIP Alumni
VIP Alumni

Hi

Does this prompt sound bad when played back on a PC at the same points as when played through UCCX?

If so then it's probably a side effect of the conversion process; using different software may help, or it it's just at 'loud' bits attenuating before conversion may help.

Regards

Aaron

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Hi aaronharrison,

Actually the prompt is played with very good quality when played from a PC directly, no issues with the wav file at all.

Maybe the volume is too high?? Is there a way where I can decrease the volume of the wav file itself or from the UCCX?

Can you describe a little more about which parts of the prompt are being distorted?

Another possibility is that if your media stream is being put through a transcoder - i.e. the server is running G711, but being trancoded intentionally or not on the way to your gateway/phone. G729 is designed to compress voice, so if you run music through it it ALWAYS sounds terrible.

If you have music that sounds bad, and voice that sounds OK, then that could be your problem. Try verifying what codec is actaully in use (e.g. from your desk phone you can press ? twice quickly to see which codec is in use when a call is active).

Aaron

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Yes u r right, that was the problem.

The prompts on the server are coded G.711 while we are in a remote site and calling them G.729. When I put my phone in the same Device Pool of the server, the call was G.711 and the sound of the music was perfect.

Is there a way to change the codecs of the server to be G.729, how can I solve this problem?

Hi

No - G729 is the problem. If you use G729, the music will sound bad.

You can set up your regions so that UCCX is in a region that runs G711 to all other regions, however this will increase your bandwidth usage a lot which may be a problem if it's running over the WAN.

Perhaps describe your topology; i.e. where your UCCX servers are, where the PSTN gateways and agents are etc....?

Regards

Aaron

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Hi,

Yes most employees and the UCCX agents are placed remotely from the server and connect to the UCCX through WAN using G.729.

But i found in the System Paramaters the codecs to be used, I found the codecs to be G.711, if I change it to G.729, will it help solve the problem? I am not sure what is the effect of this part of the configuration.

And one more thing, I checked the SRND of the UCCX 7 but did not find any guide lines for this problem of the prompts being played using G.729. I thought Cisco would have a certain recommendation for this type of problem.

Thanks a lot for your great assistance so far.

Hi

No, if you run G729 you will get poor quality music. It's just a function of the way that G729 works.

The option you mentioned makes UCCX run G729 prompts natively - if all communications to/from the UCCX server need to run G729, there's no point sending them out at g711 and having to transcode everyting. Conversely if you mainly use G711, you would have UCCX run G711 prompts so that you don't lose audio quality for no good reason.

If you need good quality, then you can do one of these two things IF your music is just played in between the prompts. If you have prompts created with background music embedded in it then you can't do this:

1) stream the music as G711 from CallManager by ensuring the MoH server is in a region that allows g711 between it and your PSTN gateways on the remote site

2) stream the music as G711 from the local gateway using multicast; there are lots of references on how to do this on this forum and on cisco.com.

If you have background music mixed in with the voice in your prompts, and you need good quality then your only real option is to stop using G729, or start again with voice-only prompts and an MoH solution as suggested above.

Regards

Aaron

Please rate helpful posts and mark answered questions that you've got a satisfactory response from to help identify useful content in the forums...
https://supportforums.cisco.com/docs/DOC-6212

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Many thanks Aaron, I guess I will go with putting the UCCX in a region where it plays G.711 for all sites to solve this problem.

Thanks a lot.

Regards

Hi

OK - just be conscious of the bandwidth implications.

If you are running G729 now, CCM sees each call as 24kbps. If you change to G711, each call is seen as 80kbps. Check your 'locations' config to ensure you don't restrict the number of calls too much, and also consider whether your WAN has enough bandwidth assigned to the high priority/EF queues.

Regards

Aaron

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
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