65
with this parameter is set to the phone number of the SMS sender.
To achieve the Call Back function, the SIP server calls the called party via its phone network and then
calls the SIP number. Since a call to this SIP number is set to forward to the phone number of the SMS
sender, both the called and calling parties can then be connected.
Example:
SMS content = 8675588228822
Sender’s number = 861380000000
SIP Server IP = 192.168.2.1
SIP Number = 20001
The INVITE message sent to the SIP Server is:
INVITE sip:[email protected]:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.2.237:5060;branch=z9hG4bK363969813
From: <sip:[email protected]:5060>;user=phone;tag=65248630
To: <sip:[email protected]>
Call-ID: [email protected]
CSeq: 2 INVITE
Contact: <sip:[email protected]:5060>
Max-Forwards: 30
User-Agent: W
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REFER, REGISTER, MESSAGE, INFO, SUBSCRIBE
Content-Type: application/sdp
Content-Length: 226
c) Mode 3
SIP Message format:
The “To” field in the SIP INVITE message contains the phone numbers of both the called and
calling parties. These two numbers are concatenated by using the asterisk (*) character with
the number of the called party in the front.
The “From” field contains the SIP number of the line that is associated with the GSM channel
Example:
SMS content = 8675588228822
Sender’s number = 861380000000
SIP Server IP = 192.168.2.1
SIP Number = 20001
The INVITE message sent to the SIP Server is:
Sending Message to 192.168.2.1:5060:
INVITE sip:8675588228822*[email protected]:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.2.237:5060;branch=z9hG4bK363969813
From: <sip:[email protected]:5060>;user=phone;tag=65248630
To: <sip:8675588228822*[email protected]>
Call-ID: [email protected]
CSeq: 2 INVITE
Contact: <sip:[email protected]:5060>
Max-Forwards: 30
User-Agent:Voptech
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REFER, REGISTER, MESSAGE, INFO, SUBSCRIBE
Content-Type: application/sdp
Содержание GoIP
Страница 26: ...26 ...