Sorry, I left out the ACK in my signaling sequence. The ACK arrives at the GW after the GW has sent the DISCONNECT message to the ISDN subscriber. Thanks Manuel UA GW ISDN INVITE -> | <- 100 Try | TX -> SETUP | RX <- CALL_PROC | RX <- ALERTING <- 183 Sess | | RX <- CONNECT | TX -> CONNECT_ACK <- 200 OK | Milliseconds later ! | TX -> DISCONNECT ACK -> | | RX <- RELEASE | TX -> RELEASE_COMP <- BYE | 200 OK -> | -- +KOM----------------------------------------------------------------+ |Manuel Görtz Merckstrasse 25| |Darmstadt University of Technology 64283 Darmstadt, Germany| |Multimedia Communications Tel: (+49) 6151 16-5175| |Multimedia Networking & Distribution Fax: (+49) 6151 16-6152| +----------------------------------------------------------------KOM+