Chapter 4: network layer chapter goals so understand principles behind network layer services. network layer service models forwarding versus routing how a router works routing(path selection) broadcast multicast ,s instantiation implementation in the internet Network Layer 4-2Network Layer 4-2 Chapter 4: network layer chapter goals: ❖ understand principles behind network layer services: ▪ network layer service models ▪ forwarding versus routing ▪ how a router works ▪ routing (path selection) ▪ broadcast, multicast ❖ instantiation, implementation in the Internet