[Serusers] ACK problem in reINVITEs with authentication

[Klaus Darilion]

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