Hi, I need kamailio proxy to reply with an ACK to 200 OK, i.e. the proxy stays in the call: UAC sends INVITE to kamailio, kamailio forward it to UAS UAS sends 180 to kamailio, kamailio forward it to UAC UAS sends 200 to kamailio, kamailio forward it to UAC AND sends ACK to UAS I was wondering what function I can use so kamailio can generate an ACK message to response to 200 OK. Apparently both t_reply () and sl_send_reply() functions create responses and not an ACK message. Thanks, Alex _________________________________________________________________ Windows Live™ Hotmail®…more than just e-mail. http://windowslive.com/howitworks?ocid=TXT_TAGLM_WL_t2_hm_justgotbetter_how…