Hi, All! I have next topology: PSTN <--- FreeSWITCH <--- channel ---> SIP-users This channel is periodically broken (for 1-10 minutes). Dialplan invoked on incoming ring have 13 endpoints, 10sec to each of 12 first endpoint, and transfer to mobile terminal via PSTN. When channel working good all is fine, but when channel is broken, we have longterm timeout to each endpoint until each of endpoint do not gone to UNREGISTER state. Endpoint gone to UNREGISTER state when REGISTER is expired, but this term is too long for me. I have turn on nat-options-ping option in sip profile, but each endpoint after unsuccessful ping don't gone to UNREGISTER state. When channel is originated to such endpoint it have lifecycle 3sec long and it have ended with NORMAL_TEMPORARY_FAILURE hangup cause. 3 secs by 12 endpoints - too long waiting. When endpoint does not registered - near zero second and ended with USER_NOT_REGISTERED hangup cause. What and where I will must modify to achieve near zero secs term of life channel to inaccessible endpoints? Thanx!