Appreciate your help very much. Below is everything recorded from syslog, including the request. I have no idea why it won't work. (I only replaced the phone number with XXXXXXXXXX).
As a side note, OBi doesn't provide a way to trigger in response to events (incoming call, phone status etc). It is a feature some people, including me, are looking for. For example, they would want to automatically pause XBMC playback on incoming phone call.
Somebody wrote a perl script to keep track of the events. But it sends HTTP query for port status XML every second, which puts a lot of load on both client and OBi box.
I think the perfect solution is to watch syslog, it is triggered by UDP packets and will be the best way to solve the problem. I may build something like when I have time and share it with people. Now it's just some thoughts.
<7> RxFrom:c0a80bfe:5060
INVITE sip:XXXXXXXXXX@192.168.11.26:5061 SIP/2.0
Via: SIP/2.0/UDP 192.168.11.254:5060;branch=z9hG4bK-d8754z-e9620904787a5d65-1---
d8754z-;rport
Max-Forwards: 70
Contact: <sip:10001@192.168.11.254:5060>
To: <sip:XXXXXXXXXX@192.168.11.26:5061>
From: "Home"<sip:10001@192.168.11.254:5060>;tag=8f7e9d6d
Call-ID: YWE4MjNlZjRiZDcwMTdkMDhjNzk1ZGY4Y2ZlNjE3ZWQ.
CSeq: 1 INVITE
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, IN
FO, MESSAGE
Content-Type: application/sdp
Supported: replaces
User-Agent: 3CXPhoneSystem 10.0.22539.0
Content-Length: 410
v=0
o=- 12969595059572250 1 IN IP4 192.168.11.13
s=CounterPath X-Lite 4.1
c=IN IP4 192.168.11.13
t=0 0
a=ice-ufrag:54a623
a=ice-pwd:87158d76464039cf541a5507397aa163
m=audio 55036 RTP/AVP 107 0 8 101
a=rtpmap:107 BV32/16000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
a=candidate:1 1 UDP 659136 192.168.11.13 55036 typ host
a=candidate:1 2 UDP 659134 192.168.11.13 55037 typ host
<7> sendto c0a80bfe:5060(337)
SIP/2.0 404 Not Found
Call-ID: YWE4MjNlZjRiZDcwMTdkMDhjNzk1ZGY4Y2ZlNjE3ZWQ.
CSeq: 1 INVITE
Content-Length: 0
From: "Dad"<sip:10001@192.168.11.254:5060>;tag=8f7e9d6d
To: <sip:XXXXXXXXXX@192.168.11.26:5061>
Via: SIP/2.0/UDP 192.168.11.254:5060;branch=z9hG4bK-d8754z-e9620904787a5d65-1---
d8754z-;received=192.168.11.254;rport=5060
<7> RxFrom:c0a80bfe:5060
ACK sip:XXXXXXXXXX@192.168.11.26:5061 SIP/2.0
Via: SIP/2.0/UDP 192.168.11.254:5060;branch=z9hG4bK-d8754z-e9620904787a5d65-1---
d8754z-;rport
Max-Forwards: 70
To: <sip:XXXXXXXXXX@192.168.11.26:5061>
From: "Home"<sip:10001@192.168.11.254:5060>;tag=8f7e9d6d
Call-ID: YWE4MjNlZjRiZDcwMTdkMDhjNzk1ZGY4Y2ZlNjE3ZWQ.
CSeq: 1 ACK
Content-Length: 0