Addressing, packet and protocols


What is a 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. A protocol may have a formal description. Protocols may include signaling, authentication and error detection and correction capabilities.

A protocol definition defines the syntax, semantics, and synchronization of communication; the specified behavior is typically independent of how it is to be implemented. A protocol can therefore be implemented as hardware or software or both. Communications protocols have to be agreed upon by the parties involved.[1] To reach agreement a protocol may be developed into a technical standard.

What is a MAC address?

A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.

What is a packet?

A piece of a message transmitted over a packet-switchingnetwork. See under packet switching. One of the key features of a packet is that it contains the destination address in addition to the data. In IP networks, packets are often called datagrams.