Hello all we are using freeswitch with a sip-proxy setup and we are trying to make match in a dialog with the ACK transaction, by receiving direclty the ACK from the UAC not passing through the proxy (as the initial INVITE does) this is the scenario for the INVITE UAC ----> PROXY ----> FSW in the proxy we are not adding record-route header, so when the UAC generates the ACK, it goes like this UAC ---------------------> FSW however, seems the FSW is not recognizing the ACK and keeps sending several 200OK back to the PROXY (because we did include Via: in the INVITE) for the INVITE here we have the parameters needed to match in the ACK construction Request-URI: sip:34666988297@79.170.68.132:5060 Call-ID: 61E072E1-A80F11E2-9934BA77-E98AD4CD@79.170.64.56 From: "EXTERNAL-CALL" <sip:34917019888@79.170.64.56>;tag=4B21F0A0-CFE for the ACK here are the parameters Request-URI: sip:34666988297@79.170.68.132:5060;transport=udp Call-ID: 61E072E1-A80F11E2-9934BA77-E98AD4CD@79.170.64.56 From: "EXTERNAL-CALL" <sip:7299@79.170.64.56>;tag=4B21F0A0-CFE maybe the difference in the user of the From and the "transport=udp" of the R-URI could explain the issue or do you know if it could be needed to add any configuration in the FSW to make the transaction match? thanks a lot and regards david escartin