When INVITE is sent and OK isn't received $DLG_status equals 2. But in the documentation $DLG_status can be NULL, 3, 4, 5. When does $DLG_status is 2? Can it has other values? WBR, Anton Zagorskiy VoIP Developer, Oyster Telecom Phone.: +7 812 601-0666 Fax: +7 812 601-0593 a.zagorskiy at oyster-telecom.ru www.oyster-telecom.ru