SIP federation between two autonomous sites

Figure 2.2. SIP federation between two sites

Figure 2.2, “SIP federation between two sites” emphasizes those components that are involved in routing a federated SIP call from one site,, to another site, For simplicity, this diagram does not show the firewalls, soft PBX or other components. Assuming the softphone users are both using NAT addresses, the TURN servers may be relaying all the media streams on their behalf.