IVR plays very fast

[pbxuser911]

Been getting complaints from our clients that when calling into our PBX (calls goes directly to a Auto Attendant) they hear the IVR Greeting speaking very fast

at first i comfort myself saying the issue happen when the call comes in from a caller using comcast, so i said "its comcast's problem"

now I'm getting add'l complaints that the problem is happening even when calling from cell phones etc

 

Ive also had issues that when someone calls my extension, it also rings my cell phone, if i don't answer and it goes to my voice mail then i get a voice message saying "you have a call from nine seven eight nice seven eight nine seven eight eight, to accept the call press one" etc

but sometimes when i hear the prompt, its being played very fast to me

 

I've also had issues where when calling the phone number, its silent, the IVR isn't heard/played by the caller

 

 

so the issue here is that at times (i cant duplicate it) the IVR Greetings are being played at FAST SPEED

and soemtimes its not being played at all

[Vodia PBX]

Blaming Comcast sounds a little bit too easy for me...

 

I guess usually the file plays at th right speed? Then I would exclude a format problem (8 kHz, 16 bit/sample, mono).

 

What could happen is that there is a congestion on the way to the client so that a lot of packets arrive at the same time. Then it would be understandable that the playback speed varies a lot. However, that should not only happen with music on hold, but also with other cases. The difference might be here, that when the customer holds the call, he has more than the usual one phone call active--the call that has the music on hold also requires bandwidth and that would explain that this happens only when moh is in the game.

[pbxuser911]

looking at the PBX Status page i see the following:

Available file system space: 16%

Uptime: 2009/12/4 01:58:59 (uptime: 18 days 15:23:41) (2942623 -1274686128--1431066544) WAV cache: 14

 

and when i check the memory on the box i see this

[root@]# free

total used free shared buffers cached

Mem: 4149620 3957236 192384 0 170032 3388176

-/+ buffers/cache: 399028 3750592

Swap: 4192956 68 4192888

 

so i rebooted the machine and now the PBX Status is:

Available file system space: 17%

Uptime: 2009/12/4 02:09:04 (uptime: 0 days 00:00:31) (22107 24399552-0) WAV cache: 1

 

and the box is:

[root@]# free

total used free shared buffers cached

Mem: 4149620 393476 3756144 0 28124 226464

-/+ buffers/cache: 138888 4010732

Swap: 4192956 0 4192956

[Vodia PBX]

So does a reboot make any difference? I still like the idea that you might end up with two media streams so that the network gets congested...

[pbxuser911]

i did reboot and it helped

[Vodia PBX]

i did reboot and it helped

 

Well, that is very strange. Maybe there is a problem with the timer subsystem. Though I did not hear about it for a long time, but there is hardware that has a lot of jitter in the precision timer, so that callbacks in the ms range become difficult. It would explain why the playback would be too fast. Is there anything special about the hardware? Does e.g. a softphone play smooth on that hardware?