Communication between two computers or between two devices does not happen by just assembling pieces together. All devices require a way to communicate. Network protocol defines those rules for communication between the network devices. Network protocols define the mechanisms to make the communication between two devices possible by means of identification of devices, formatting rules for the packaging of data into messages while sending and receiving and so on. There are also protocols for message acknowledgement and data compression for an effective and reliable network communication.
Nowadays, computer networking makes use of packet switching techniques for sending and receiving messages. The technique involves dividing messages into pieces in the form of packets and being sent through the network and while receiving they are collected and assembled again. There are several other protocols designed and developed like this to cater to different purposes.
Purpose of Network Protocols
As mentioned above, devices do not have the ability of their own to interact with each other. They do not understand the signals sent over the network signals. This is where the Network protocols come into the picture. The basic functions of the network protocols transmit:
- data to the correct recipients / destination
- Apply for security protection, if necessary.
- Receive the data and send responses (acknowledgement), if asked for.
It works similar to the physical postal service. The postal service sorts, manages and sends letters from the sources to the destinations. The network protocols work in the same way by keeping the data flow along the network paths continuously. But unlike the physical postal service, the flow of data is continuous to the destination. This is called streaming. Also, it copies a single message and broadcasts it to multiple destinations called broadcasting.
The characteristics that differentiate one protocol from the other are
- The type of connection – Simplex connections that allow only one device to communicate on the network whereas Duplex connections allow multiple devices on the network.
- Connection oriented protocol where a session is created by exchanging the address information between devices for conversing whereas a in a connection-less protocol, individual messages are sent and from source to destination irrespective of the messages sent previously.
- Network protocols work at different levels. While the low-level protocols are related to the network cabling level, high-level protocols work at the network application level.
The Internet protocols is a family of related network protocols. Higher protocols like the TCP, UDP, HTTP and FTP, and lower protocols like the ARP and ICMP integrate in the Internet Protocols to give the required capability. While the higher-level protocols interact with web browsers, the lower-level protocols interact with network adapters and the hardware of the computer.
Wireless Network Protocols
We are all familiar with the wireless networks. Wi-Fi, Bluetooth and LTE are such wireless networks and wireless network protocols are designed to work on wireless networks. These protocols are designed to support the mobile devices on roaming and should also be able to handle variable data and security over the network.
Network Routing Protocols
Network Routers on the Internet require a special type of protocols that should be designed for making dynamic routing decisions. These protocols are special-purpose protocols that will identify other routers, manage routes (the pathways) between the source and destination and above all, make routing decisions. Some of the Network routing protocols are EIGRP, OSPF and BGP.
Implementation of Network Protocols
There are built-in software services in the operating systems that support some of the popular network protocols. High-level protocols are supported by software libraries in the web browsers and is a necessary element for the application to function. Some of the lower-level protocols like the TCP/IP is implemented in the hardware to improve performance.
The packets sent and received through the network is in the form of binary data. Each packet will have a header that has information about the sender of the message and the source and destination information. There would sometimes also be a footer. The network protocol that is intended to receive the message will have the capability to identify the message packets and will be able to process both the header and footer. This ability is required as part of moving the messages among devices.
When a group of such network protocols work together (both at the lower and higher levels), they are grouped together and called as a protocol family. These protocols are organized as specific layers conceptually.