Addressing, Packets and Protocols

All you need to know about Addressing, Packets and Protocol.


Every machine on a network has a unique identifier. Just as you would address a letter to send in the mail, computers use the unique identifier to send data to specific computers on a network. Most networks today, including all computers on the Internet, use the IP protocol as the standard for how to communicate on the network. In the IP protocol, the unique identifier for a computer is called its IP address.

Data Packets

A packet is one unit of binary data capable of being routed through a computer network. To improve communication performance and reliability, each message sent between two network devices is often subdivided into packets by the underlying hardware and software.


Protocol is a set of rules that computers follow when communicating with each other. In information technology, a protocol is the special set of rules that end points in a telecommunication connection use when they communicate. Protocols specify interactions between the communicating entities. Protocols exist at several levels in a telecommunication connection. For example, there are protocols for the data interchange at the hardware device level and protocols for data interchange at the application program level. In the standard model known as Open Systems Interconnection (OSI), there are one or more protocols at each layer in the telecommunication exchange that both ends of the exchange must recognize and observe. Protocols are often described in an industry or international standard. TCP stands for TRANSMISSION CONTROL PROTOCOL and this is one of the core protocols of the Internet protocol suite. TCP is one of the two original components of the suite, complementing the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered delivery of a stream of octets from a program on one computer to another program on another computer.

MAC and IP addressing

A MAC address, or Media Access Control address, is a 48- or 64-bit address associated with a network adapter. While IP addresses are associated with software, MAC addresses are linked to the hardware of network adapters. For this reason, the MAC address is sometimes called the hardware address, the burned-in address (BIA), or the physical address. MAC addresses are expressed in hexadecimal notation in the following format: 01-23-45-67-89-AB, in the case of a 48-bit address, or 01-23-45-67-89-AB-CD-EF, in the case of a 64-bit address.