Outbound audio dropping at 10 minute mark

Hi all,

I’ve seen a few open topics with similar titles but none that really seem to get to why this is happening. I have this issue where, when calling outbound from my PBX to some certain friends cellphones, they stop being able to hear me usually exactly at 10 minutes into the call. I can hear them, they just can’t hear me.

A couple other things I’ve noticed while playing around with this issue for several weeks:

  • This only happens when the friend’s cellphone is on LTE/5G. If they are wifi calling there is no problem
  • This doesn’t happen for everyone. I’ve been on support calls for over an hour with no issue, only a few friends with their cellphones
  • I can create this issue immediately by calling using a softphone and switching from wifi to LTE during the call on the softphone device, same results as above where my audio stops going

A preliminary look through very verbose logs doesn’t seem to indicate any issue, but I’m a bit of a noob so there could be something I’m missing. Any help would be appreciated. I can provide logs if needed.

This really doesn’t make sense. Your PBX system doesn’t care, and doesn’t even know, if a cell phone is on wifi or cellular. It doesn’t even know that the other party is a cell phone at all.

You probably need to look at wireshark logs. Your sip trunk provider probably has these available in their web portal.