1.3 Protocol and Internet

1.3.1 Definition of Network Protocol

A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications.

1.3.2 Function of Protocol

  1. signaling
  2. authentication
  3. error detection and correction

1.3.3 Protocol Design

  1. syntax,
  2. semantics, and
  3. synchronization of communication

1.3.4 Internet Protocol in OSI Model:

The Internet Protocol Suite is the set of communications protocols used for the Internet and other similar networks. It is commonly also known as TCP/IP named from two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were the first two networking protocols defined in this standard.

Modern IP networking represents a synthesis of several developments that began to evolve in the 1960s and 1970s, namely the Internet and local area networks, which emerged during the 1980s, together with the advent of the World Wide Web in the early 1990s.

The internet utilize only 4 layers in the OSI model, namely the Link Layer, the Internet Layer, the Transport Layer, and the Application Layer. The layers define the operational scope or reach of the protocols in each layer, reflected loosely in the layer names. Each layer has functionality that solves a set of problems relevant in its scope.

Internet Protocol Suit & OSI Model

Internet Protocol Suite
Application Layer
Transport Layer
Internet Layer
IP (IPv4IPv6)  ICMP  ICMPv6  IGMP IPsec  (more)
Link Layer
ARP/InARP  NDP  OSPF Tunnels (L2TP)  PPP  Media Access Control (Ethernet, DSLISDNFDDI(more)
OSI Model

Data unitLayerFunction
Data7. ApplicationNetwork process to application
6. PresentationData representation, encryption and decryption, convert machine dependent data to machine independent data
5. SessionInterhost communication
Segments4. TransportEnd-to-end connections, reliability and flow control
Packet/Datagram3. NetworkPath determination and logical addressing
Frame2. Data LinkPhysical addressing
Bit1. PhysicalMedia, signal and binary transmission

References Links