Hi all, i've 2 asterisk box with dahdi (server A ver. 1.4.29 and server B ver. 1.4.26) connected with IAX channel using gsm codec. - Calling from A to B the call has no problem: ring , answer a speak without problem. - Calling from B to A : B phone always listen ring also when A phone answer. After answer A phone don't listen anything. when A phone hangup the call disconnect. full logger in each server show normally ringing and hangup Any idea will be really appreciated thanks a lot in advance Lorenzo -- "Chi vive sperando muore cagando ... Lo Russo isoletta dell'Egeo che non conta un cazzo, 1941 ... sono anche un autore"