Communication inside the Wide Area Network (WAN)

The following figure and description show the routing inside the Wide Area Network (WAN).

Figure 2-5 Communication inside the WAN

1. The Source Host (Signaling Gateway) builds a packet with a destination IP address.
2. A router on the LAN converts the packet to the WAN protocol and places it on the WAN.
3. Each router on the WAN looks at the destination IP address and determines the port to which it forwards the packet. Each router needs to know only how to get the packet closer to the destination.
4. The final router converts the packet to the local LAN format and delivers it to the Destination Host.