...

...

Prerequisites

SBC SIP-to-SIP Basic Call Processing Flow

...

1. The call is received by the SBC. The Source IP addresses is matched against the Federated IP addresses contained in all the Signaling Groups (SG).
   1. The SG with the closest matching Federated IP is selected to process the incoming call.?
   2. In the case above, the Federated IP, host1.vx.net/32, exactly matches the sending host's source IP as resolved via DNS (host1.vx.net).?
   3. Of course, the transport type and incoming port must also match.
2. The SG defines the Call Routing Table to use for processing the call, sba: SIP to ISDN in this case.
3. The Call Routing Table contains a list of call routing entries.?
4. Those call route entries define which Transformation Table (sba:Lync to SIP Reg) to use in manipulating the call's numbers, names, etc.
5. If the transformation is valid, the call is passed to the Destination Signaling Group (10.1.1.91 SG) defined in the call route entry.
6. The Egress Signaling Group contains the configuration for the (egress) SIP Server Table (10.1.1.91)

...