I have a Elastix box set up with 8 analog phone lines in one trunk group. 99.99% of the time it works perfectly. The rare, but recurring problem is that sometimes when an incoming caller calls at the exact same time as someone goes to make an outgoing call, Asterisk grabs the line that the incoming caller is calling in on. This results in the incoming caller bypassing the IVR and connecting to the outgoing callers extension midway through dialing. It's as if the system is picking a line for the outgoing call before it realizes that it already has an incoming call on that line. I've experienced this problem personally so I know my users aren't making it up, but we are not able to recreate it reliably. I'm stumped and not sure where to start. Is this a phone company issue? Do I need to configure asterisk differently? If anyone has any suggestions as to where I should start or things to check, I'd be most grateful!