[HELP]: No audio during first 10 seconds of SIP calls

SIP to SIP calls connected through Asterisk only get audio about 10 seconds or so after the call connects.

However, calls answered by the an application (namely voicemail) get audio as soon as the call connects AND calls setup from the command line ‘channel originate…’ also get audio right away.

The forums have a lot of ‘no audio’ or ‘one-way audio’ issues identified and resolved, but I couldn’t find an issue closer to what I’m experiencing. Please help!

Setup:
version 1.6.2.5-0ubuntu1 running on a vps
all sip accounts configured with canreinvite=no, directmedia=no