An incoming call to a specific number (for example +1-80-41774568) is forked to both the AORs (for example AOR1:+1-80-41774568 and AOR2: sip:bob@sonusnet.com) simultaneously via PBX1 and PBX2.
Both the AORs belong to different call servers. These two devices are handled by the redundant call servers.
In the below scenario, the SBC forks the call to routes R1 and R2. The routes R1 contains the egress INVITE R-URI as +1-80-41774568 and the routes R2 contains the egress INVITE R-URI as sip:bob@sonusnet.com.