Record() ends too soon. Is there a silencethreshold for sip?

I am running an OpenVox GSM gateway using Asterisk It is a firmware that can’t be upgraded. I have tried setting rxgain and txgain there, but it crashes the system and it fails to do anything till that is removed. I remember trying to set the gains on a Asterisk 11 server before upgrading to 13 and don’t remember achieving much success, but maybe I should try again.

I am now running Asterisk 13 on a Dell server that ties into the GSM gateway using SIP to receive incoming calls. I have it recording and then playing back audio from the users, but it often cuts out too soon, unless I am speaking unnaturally loud.

exten => s,n,Record(/var/lib/asterisk/sounds/outboundmsgs/temp_recording:wav,4,25)

Is there a good way to adjust the thresholds for silence detection for the Record() application like there is for AMD?

I was able to have some success by setting it like this:

exten => _.,n,Set(VOLUME(TX)=2)
exten => _.,n,Set(VOLUME(RX)=8)

I didn’t think it was working because no matter what I set the TX volume to, my Verizon cell phone sounds the same when listening to the prompts. Verizon may have some volume balancing on their end that prevented me from seeing it working till I looked at the wave forms of what was recorded and saw them boosted.