1.
------
Reliably Transmitting (no NAT) to 192.168.0.31:5060:
NOTIFY sip:20@192.168.0.31:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 192.168.0.10:5060;branch=z9hG4bK3eb4f73e;rport
From: "asterisk" <sip:asterisk@192.168.0.10:5060>;tag=as4004c4a5
To: <sip:sip:20@192.168.0.31:5060;user=phone>;tag=c0a80101-18e1
Contact: <sip:asterisk@192.168.0.10>
Call-ID: 31a4-c0a80101-d-2@192.168.0.31
CSeq: 105 NOTIFY
User-Agent: ProNet PBX
Max-Forwards: 70
Event: message-summary
Content-Type: application/simple-message-summary
Subscription-State: active
Content-Length: 98

Messages-Waiting: yes
Message-Account: sip:asterisk@192.168.0.10:5060
Voice-Message: 1/1 (0/0)


---
<--- SIP read from 192.168.0.31:5060 --->
SIP/2.0 481 CallLeg/Transaction Does Not Exist
Via: SIP/2.0/UDP 192.168.0.10:5060;branch=z9hG4bK3eb4f73e;rport
From: "asterisk"<sip:asterisk@192.168.0.10:5060>;tag=as4004c4a5
To: <sip:sip@192.168.0.31:5060;user=phone>;tag=c0a80101-18e1
Call-ID: 31a4-c0a80101-d-2@192.168.0.31
CSeq: 105 NOTIFY
Content-Length: 0

<------------->
--- (7 headers 0 lines) ---
[Jul  2 11:54:00] WARNING[17856]: chan_sip.c:12920 handle_response: Remote host can't match request NOTIFY to call '31a4-c0a80101-d-2@192.168.0.31'. Giving up.
Really destroying SIP dialog '7b39ae2518b4482423827394489cab57@192.168.0.10' Method: BYE








2.
-------




Reliably Transmitting (no NAT) to 192.168.0.31:5060:
NOTIFY sip:20@192.168.0.31:5060;user=phone SIP/2.0
Via: SIP/2.0/UDP 192.168.0.10:5060;branch=z9hG4bK3eb4f73e;rport
From: "asterisk" <sip:asterisk@192.168.0.10:5060>;tag=as4004c4a5
To: <sip:sip:20@192.168.0.31:5060;user=phone>;tag=c0a80101-18e1
Contact: <sip:asterisk@192.168.0.10>
Call-ID: 31a4-c0a80101-d-2@192.168.0.31
CSeq: 106 NOTIFY
User-Agent: ProNet PBX
Max-Forwards: 70
Event: message-summary
Content-Type: application/simple-message-summary
Subscription-State: active
Content-Length: 98

Messages-Waiting: yes
Message-Account: sip:asterisk@192.168.0.10:5060
Voice-Message: 1/1 (0/0)

---
voip*CLI>
<--- SIP read from 192.168.0.31:5060 --->
SIP/2.0 481 CallLeg/Transaction Does Not Exist
Via: SIP/2.0/UDP 192.168.0.10:5060;branch=z9hG4bK3eb4f73e;rport
From: "asterisk"<sip:asterisk@192.168.0.10:5060>;tag=as4004c4a5
To: <sip:sip@192.168.0.31:5060;user=phone>;tag=c0a80101-18e1
Call-ID: 31a4-c0a80101-d-2@192.168.0.31
CSeq: 106 NOTIFY
Content-Length: 0

<------------->
--- (7 headers 0 lines) ---
[Jul  2 11:57:18] WARNING[17856]: chan_sip.c:12920 handle_response: Remote host can't match request NOTIFY to call '31a4-c0a80101-d-2@192.168.0.31'. Giving up.