Network layer transport segment from sending to receiving host applicatior TransporT ▣on sending side network data link physical network encapsulates segments network data link network data link physical data link physical physical into datagrams network data link on rcving side,delivers physical network data link segments to transport physical network layer network data link data link physical physical network layer protocols network data link application in every host,router physical transport network data link Router examines header physical fields in all IP datagrams passing through it Network Layer 4-4Network Layer 4-4 Network layer  transport segment from sending to receiving host  on sending side encapsulates segments into datagrams  on rcving side, delivers segments to transport layer  network layer protocols in every host, router  Router examines header fields in all IP datagrams passing through it network data link physical network data link physical network data link physical network data link physical network data link physical network data link physical network data link physical network data link physical application transport network data link physical application transport network data link physical