The TCP/IP networking protocols are the result of an evolutionary expansion of the global computer network protocols ARPANET.
The experience gained in operating the ARPANET network by 1974 revealed many of the shortcomings of the NCP protocols and made it possible to determine the basic requirements for a new set of protocols called TCP/IP:
- independence from the messaging environment;
- the ability to connect to a network of computers of any architecture;
- a single way of organizing the connection between nodes in the network;
- standardization of application protocols.
The currently widely used version 4 of TCP / IP protocols were standardized in 1981 in the form of documents called RFCs (Request for Comment). The full transition of the ARPANET network to new protocols was completed in 1982. This network played the role of the “germ” of the worldwide Internet network built based on TCP / IP protocols.
The implementation of TCP / IP protocols was the most successful in versions of BSD4.2 and BSD4.3 of the UNIX operating system.
Internet Protocol (IP) is specified in RFC 791. Its main characteristics are listed below:
- implements the exchange of information packets, which will be called IP-segments (the maximum size of the IP-segment – 65535 bytes);
- is a protocol without establishing a logical connection;
- provides, if necessary, the fragmentation of IP segments;
- IP segments have a finite network lifetime;
- does not have the means to control the rate of transmission of IP-segments by the sending side (flow control);
- does not guarantee the correct sequence of IP segments on the receiving side;
- does not guarantee the reliability of delivery of IP segments to the address;
- for addressing network nodes, the address is 4 bytes long which is known as IP address.