CITS3002 Computer Networks  
← prev
next → CITS3002 help3002 CITS3002 schedule  

Internet Protocol (IP) Datagrams

The Internet Protocol (IP) provides an unreliable, best-effort, connectionless, packet delivery system.

In this unit we will initially be discussing Internet Protocol version 4 (IP v4) RFC-791.

Internet datagrams resemble 'standard' physical-layer frames, but are designed to be encapsulated within the normal network framing schema. Hence, Internet datagrams are said to run on top of traditional networks.

ipformat
  • Checksum: 16 bit checksum of the header only. The checksum is the one's complement of the one's complement sum of the header.
  • TTL: Time to live - the hop count.
  • Length: The datagram length (16 bits) in octets.
  • Type: 8 bits, identifying protocol types. 


# Internet (IP) protocols
#
ip    0    IP      # internet protocol, pseudo protocol number
icmp  1    ICMP    # internet control message protocol
igmp  2    IGMP    # internet group multicast protocol
ggp   3    GGP     # gateway-gateway protocol
tcp   6    TCP     # transmission control protocol
pup   12   PUP     # PARC universal packet protocol
udp   17   UDP     # user datagram protocol


CITS3002 Computer Networks, Lecture 7, The TCP/IP protocol suite, p19, 17th April 2024.