Hi, 

I have a short question about ACK. Im my case it is not sent from
callking side (X-lite). Why is it like that? How does Xlite know, not
to send ACK? And why there is no BYE? See flow above.

Flow:

No.     Time        Source                Destination          
Protocol Info
     45 6.979169    137.138.137.166       192.168.2.2          
SIP/SDP  Request: INVITE sip:6891@wilanowska.homeip.net, with session
description
     46 6.979736    192.168.2.2           137.138.137.166       SIP  
   Status: 100 trying -- your call is important to us
     47 6.979950    192.168.2.2           81.18.210.159        
SIP/SDP  Request: INVITE
sip:6891@81.18.210.159:10020;rinstance=18352dcff8f568bc, with session
description
     51 7.241103    192.168.2.2           81.18.210.159        
SIP/SDP  Request: INVITE
sip:6891@81.18.210.159:10020;rinstance=18352dcff8f568bc, with session
description
     52 7.286054    81.18.210.159         192.168.2.2           SIP  
   Status: 180 Ringing
     53 7.286401    192.168.2.2           137.138.137.166       SIP  
   Status: 180 Ringing
     54 7.320840    81.18.210.159         192.168.2.2           SIP  
   Status: 180 Ringing
     55 7.321229    192.168.2.2           137.138.137.166       SIP  
   Status: 180 Ringing
    102 14.357178   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    103 14.357744   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    104 14.955213   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    105 14.955567   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    109 15.960539   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    110 15.961118   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    117 17.968614   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    118 17.969011   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    135 21.982902   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    136 21.983229   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    171 25.999316   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    172 25.999641   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    193 30.018608   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    194 30.018936   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    229 34.031607   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    230 34.032134   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    251 38.053494   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    252 38.054124   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    269 42.070209   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    270 42.070736   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description
    325 46.088117   81.18.210.159         192.168.2.2          
SIP/SDP  Status: 200 OK, with session description
    326 46.088445   192.168.2.2           137.138.137.166      
SIP/SDP  Status: 200 OK, with session description

cheers,

Daniel