Core Layer for the WAN Network

Core Layer for the WAN Network
The devices in the core of a WAN network are usually very-high-speed routers that can sustain
operating at very high bandwidths. They look at the layer 3 address within each packet and switch
the packet to the outbound interface based upon that address. High-speed switching techniques,
such as Cisco Express Forwarding (CEF), are utilized to increase packet-switching speed and
ensure that packets are not delayed.
Like the distribution routers, they are connected to one another to ensure an optimum path
through the backbone. With route summarization, the routing tables in the core routers should
be pretty small to ensure a shorter lookup time and conserve system resources.