Link layer:introduction terminology: mobile network hosts and routers:nodes national or global ISP communication channels that connect adjacent nodes along communication path:links ·wired ·wireless ·LANS layer-2 packet:frame, datacente encapsulates datagram link layer has responsibility of transferring datagram from one node enterprise to physically adjacent node over a link network LinkLayer:6-4 Link layer: introduction terminology: ▪ hosts and routers: nodes ▪ communication channels that connect adjacent nodes along communication path: links • wired • wireless • LANs ▪ layer-2 packet: frame, encapsulates datagram mobile network enterprise network national or global ISP datacenter network link layer has responsibility of transferring datagram from one node to physically adjacent node over a link Link Layer: 6-4