Dear all & supporters, Now, we're using Elastix 1.6-12. Everything is perfect. But the problem was happen when use remote extension. Extension was registered...ring...hear nothing both ways. (But everything work probably when we try to test with Asterisk 1.4 & FreePBX 2.5 build-by-hand ... is OK) My network: ADSL --- Modem ---- LAN ---- Elastix Any one please support us in this case. How to NAT Elastix work with remote extension? Look forward to hearing from any one soonest ! Steven.