[Serusers] ACK problem in reINVITEs with authentication

Hi! It looks like I still have to learn a lot to understand ser, so maybe someone can help me: Following scenario: IP-IP with reINVITE (call hold). I authenticate all INVITEs, also reINVITEs. The call setup works fine: UA1 Proxy UA2 | -INVITE w/o cred ->| | | <--- 407 ---- | | | ---- ACK ---> | | The ACK is processed and caught by ser automagically without entering the routing script. I guess this is done by the stateless processing because of the debug message: Aug 14 22:34:47 sip1 /usr/sbin/ser[25694]: DEBUG: sl_filter_ACK : local ACK found -> dropping it! Then INVITE with credentials: UA1 Proxy UA2 | --INVITE w cred -> | | | | ---- INVITE ----> | <- ...100, 180 ... -- | | <--- 200 OK --- | | <--- 200 OK ----- | | | ----- ACK ----> | | | | ----- ACK ----> | The ACK will be forwarded correct. Now the problem: A reINVITE will be sent to the proxy, and the proxy ask for credentials. This time, the ACK want be catched by ser and enters the routing script, and therefore will be forwarded to UA2 (which should not!). UA1 Proxy UA2 |-reINVITE w/o cred->| | | <--- 407 ---- | | | ---- ACK ---> | | | | ---- ACK ---> | How can I configure ser to also handle this ACK automagically? regards, Klaus