Voicemail message no audio

[3397premier]

We have an issue were voicemails from a specific company are missing audio for the first 3-15 seconds and then it comes through. I have tested on two SIP providers to see if that may have been the issue. I installed a codec pack on our server. We also have turned on the extensions: PBX Delivers Audio, Support Reinvite and Support Headers. We are using a Dell R510 server for the 3CX. Any suggestions are appreciated.

Thank you,

 

[leejor]

Does the same company have a similar if they call one of your extensions directly? How do they go into the voicemail? Via a busy/unanswered extension (same one each time?), via automated attendant?

Is it more than one person at this company that has the issue leaving a message?

No one else, leaving a message, has this issue?

 

[3397premier]

It can be from any number from that company, they have many sites in different states. It happens when they call a DID or into our main # and then dial someones extension. It happens anytime they leave a voicemail no matter if its because the # is busy or it just forwards to voicemail after a period of time that no one answers. No one else leaving voicemail has that problem.

We tested through a softphone, with PBX delivers audio on or off and same with support reinvite and support headers (on extension).

 

[leejor]

But, if they call an extension, and the person is there to answer, is audio cut through immediately?

 

[3397premier]

Yea, if they answer the phone the audio comes in just fine. Its just when they leave a voicemail.

 

[3397premier]

It looks like the 3CX is sending RTP traffic (the VM greeting I believe) back before sending the 200 OK response to the Invite. And maybe because those are out of order, the caller’s system starts sending the RTP traffic (the message left by the caller) before 3CX is ready to receive it. I am not sure how this can be updated or if there is anything else we can do to try and correct.

I attached a screenshot of two captures that our SIP provider took when testing on a Digium Switchvox where the voicemail does work correctly and the test 3CX server that does not. It uses the same modem, cables and SIP provider when testing. We tested this without using one of the IP phones to make sure that was not an issue. Please let me know what you think. The good capture is on the left (Digium Switchvox) and the bad voicemail on the right (test 3CX server).

 

[SY]

It looks like the 3CX is sending RTP traffic (the VM greeting I believe) back before sending the 200 OK response to the Invite. And maybe because those are out of order, the caller’s system starts sending the RTP traffic (the message left by the caller) before 3CX is ready to receive it. I am not sure how this can be updated or if there is anything else we can do to try and correct.

Sorry, but all assumptions are not correct.
Voice mail recording is an interaction between "machine"(IVR/Voicemail) and caller.
If "caller" is also a "machine" then your suspicions may be valid.

Please add information about this case

thanks

 

[3397premier]

The caller is not a recording. This happens for one specific company that tries to call us, no other issues. If we answer the phone everything works well, just that issue in the voicemail. I am not sure why it would work correctly on a different PBX system but it does, every time. Any suggestions on where we could check to resolve? Could this be a 3CX software issue or is it something else?

 

[microage]

We're experiencing this as well from a select group of customers. Did you ever find a solution for this?