Introduction to Networking

Network Protocols

Network protocols are a set of rules or standards used by networks for communication of different devices connected to a network. Protocols define what, when, and how to communicate. Devices can’t communicate without protocols. Different layers of the OSI model use different protocols.

Function of protocols

There are several functions of protocols discussed below

  • Sequencing Data: Breaking a long message into smaller blocks/packets.
  • Routing Data: Finding the most efficient path between source and destination before sending data.
  • Flow Data: if the sender computer is faster than the receiver computer, then protocols manage it.
  • Error control: it handles the errors if an error is detected.

Key elements of the protocol

I. Syntax

Syntax is the format of data. For example, the first 8 bits represent the address of the sender, the last 8 bits represent the address of the receiver, and the rest represent the actual message.

II. Semantics

It tells the meaning of bit of each section. For example, it tells the meaning of

  • First 8-bits: represent the sender address
  • The last 8-bits represent the destination address
  • And meaning bits: represent the actual message

iii. Timing

Timing indicates

  • When data should be sent
  • How fast it can be sent

For example, sometimes the sender sends the data at 100Mbps, and the receiver receives it at 1Mbps. This overhead causes the loss of data.

Network Standards

The Network standards are designed by two main organizations, the American National Standard Institute (ANSI) and IEEE.

These network standards are very important for the computer industry because they help manufacturers produce compatible hardware and software.

Some main network standards are given below.

1. Ethernet (802.3)

  • This standard is used in wired networks (LAN).
  • Data Transfer rate from 10 Mbps to 100Gbps
  • Ethernet standard networks follow the P2P model where no server computer is present.
  • Collision may occur when two devices attempt to send the data at the same time.  This issue can be resolved by resending data.

2. Token Ring

It is an alternative to Ethernet used in wired networks (LAN). It uses a special signal called a token or ticket.

Any device in the network may transmit the data only if it has a token.  Without a token/ticket, the device cannot communicate with the network. In this way, there is no chance of collision. However, data speed is slow compared to Ethernet.

When a computer in the token ring standard network wants to send a message, it

  • Gets the token
  • Puts the data in a token
  • Adds the address of the receiving computer

Token passes from computer to computer; the computer whose address matches with the mentioned (destination) address in the token will receive the data. It also sends acknowledgment signals to the sender to indicate that the message has been received successfully.

Token rings follow the ring topology and are also used in start topology. Its data transfer rate is from 4Mbps to 1Gbps.

3. TCP/IP

  • TCP/IP stands for transmission control protocol/ internet protocol. This protocol is most widely used nowadays.
  • It transfers data over the internet through two protocols: one is TCP, and the other is IP.
  • TCP is responsible for the delivery of data. It divides the data into small packets and transfers it over the internet. These packets resemble each other properly in order when they reach the destination.
  • IP tells the address and routing information. Small Packets travel over the internet with the help of a router.

4. Bluetooth

  • In this standard, data is transmitted between two Bluetooth devices using short-range radio waves.
  • The distance between the two devices must be within the range of 33 feet.
  • Bluetooth devices use a small chip to communicate with other Bluetooth devices.
  • A Bluetooth wireless port adapter is used to convert existing USB ports to Bluetooth ports.
  • Most devices like desktop computers, notebook computers, laptops, smartphones, keyboards, mouse, printers, etc., are Bluetooth-enabled.
  • The data transfer rate is 3 Mbps.
  • It has low power consumption, low speed, and high security as compared to WiFi.

5. WiFi

It is a wireless network standard developed by IEEE. Various wifi standards support different speeds and distances, as explained below.

802.11 Standards Maximum Speed
802.11 b 11 Mbps
802.11 g 54 Mbps
802.11 n 300-600 Mbps
802.11 ac 1.8 to 3.6 Gbps
802.11 ad 6.7 Gbps

An example of a wifi network is a hotspot. Hotspot is used by mobile users to connect wifi-enabled devices.

The distance between hotspots and wifi-enabled devices must be within the range of 300 feet in an open area and 100 feet in a closed area.

High power consumption, High speed, and low security as compared to Bluetooth.

6. IrDA

  • It transmits data wirelessly through infrared light waves
  • Data transfer speed is 115 Kbps to 4Mbps
  • It requires a line-of-sight for data transmission. It means sending and receiving devices must be in line. There should be no obstacle between these devices.

7. WiMax

  • WiMax stands for worldwide interoperability for microwave access.
  • It is used for a long wireless connection.
  • It is faster and has a greater range than Wi-fi.
  • WiMax devices communicate with each other’s by using radio waves via the WiMax tower.
  • tower of WiMAX can cover a radius of up to 30 miles.
  • WiMax is of two types: Fixed wireless and  Mobile wireless WiMAX.

Note: some other network standards are

  • NFC (near-field communication)
  • RFID (radio frequency identification)
  • WAP (wireless application protocols)