Defined in STD 5, RFC 791, is the network
layer for the TCP/IP Protocol Suite, a packet-switching
protocol that has address and control information so that packets can be routed
(see Figure 9-2). Both the Transmission
Control Protocol (TCP) and
the Internet Protocol (IP) are
important. IP provides connectionless, high-level datagram delivery as well as
fragmentation and datagram reassembly to support data links having varying
maximum-transmission unit (MTU)
sizes.
The Internet Protocol itself contains the following
information:
The IP addressing setup is critical to the effective routing
of IP datagrams through the Internet because every IP address, having specific
components and following a given format, can be subdivided and used to generate
addresses for sub-networks. Each device on a TCP/IP network is given a unique
numerical address (32 bit in IP version 4) that can be divided into two parts:
the host number and the network number. The host number identifies a computer
on the network and is given by the administrator of the local network, whereas
the network number identifies a network and must be given by one of the local
Internet Registries (that is, ARIN, RIPE, APNIC, AfriNIC, or LACNIC) if the
network is to be connected to the Internet. An Internet
Service Provider (ISP) can
get blocks of network addresses and thereby assign address space to clients.
See Also:
Internet Control Message Protocol (ICMP); TCP/IP or Transmission Control
Protocol/Internet Protocol; User Datagram Protocol (UDP).
QUT Division of Technology, Information and Learning Support. Network Glossary.
[Online, July 17, 2004.] QUT Division of Technology, Information and Learning
Support Website. http://www.its.qut.edu.au/network/glossary.jsp.