i'm trying to find out why handle_uri_alias() function is not finding any params in ACK request. i have in script just before handle_uri_alias() call debug statement that prints $rm and $ru and it shows correctly: Apr 1 17:00:45 lohi /usr/sbin/sip-proxy[22980]: INFO: handling uri alias of ACK sip:+35862345670@192.168.15.100:5060;user=phone;alias=86.133.100.125:5060t1 handle_uri_alias() has in the beginning if ((msg->parsed_uri_ok == 0) && (parse_sip_msg_uri(msg) < 0)) { LM_ERR("while parsing Request-URI\n"); return -1; } rest = msg->parsed_uri.params.s; rest_len = msg->parsed_uri.params.len; LM_INFO("params are %.*s\n", rest_len, rest); if (rest_len == 0) { LM_INFO("no params\n"); return 2; } and here is what comes to syslog: Apr 1 17:00:45 lohi /usr/sbin/sip-proxy[22980]: INFO: nathelper [nathelper.c:1513]: params are Apr 1 17:00:45 lohi /usr/sbin/sip-proxy[22980]: INFO: nathelper [nathelper.c:1515]: no params why is msg->parsed_uri.params empty str after calling parse_sip_msg_uri()? -- juha