How SIP Trunking Works
Here is a diagram that shows how SIP Trunking works. You’ll see that on the left hand side is your Public-Switched Telephone Network. As you move along the communication line and to the center you’ll see the Internet Telephony Service Provider, this is the area where SIP Trunking occurs. It is in here that the calls are routed to the correct PBX. Once the call reaches the PBX, the PBX will direct it to the EDGE.
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