[Serusers] ZyXEL ACK Problem.

[markus monka]

It is a ZyXEL Phone connected to a ZyXEL Wlan Router.


Sending INVITE 


INVITE => SER => ASTERISK 

ASTERISK send "Session Progress" everything is fine:
ASTERISK sends "OK" 

Session starts. I can hear my Voice. After 6 Seconds 
Session breaks up.

Something seems to be strange with the ACK the ZyXEL
Phones sends:

PHONE => PROXY
ACK sip:0xxxxx at 21.1.7.9 SIP/2.0
Via:SIP/2.0/UDP 21.28.17.18:5060;branch=z9hGddbkb8a7ca191bf4fd
From:Zyxel<sip:1111111 at domain.de;user=phone>;tag=C2E2D6CF845EA11AEBC2
To:<sip:0xxxxxxxxx at domain.de;user=phone>;tag=as4f89971f
Call-ID:15482-E655-54C3-B488-1D32D8DF7653 at 21.28.17.18
CSeq:1 ACK
User-Agent: ZyXEL P2000W VoIP Wi-Fi Phone
Route:<sip:49xxxxx at 21.1.7.8;ftag=C2E2D6CF845EA11AEBC2;lr=on>,<sip:492405690929 at 21.28.17.18:5060>


When loggin with debug = 10 , i do not see some errors in syslog.

The Gateway then sends 6 more "OK" and the terminate by sending "BYE".
The Phone answers with "200 OK" .. ?


Regards,
Markus