Datagram Packets in the ip layer are called datagrams The lengths of different datagrams vary a datagram consists of two parts Header Data The header is 20-60 bytes in length contains information for routing CSIE NTUT TANANCSIE, NTUT, TAIWAN 6 Datagram • Packets in the IP layer are called datagrams. • The lengths of different datagrams vary • A datagram consists of two parts: – Header – Data • The header – is 20-60 bytes in length – contains information for routing