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