Understanding common network protocols

A deeper exploration into the world of inter-computer communications will reveal more types of communications, their interfaces and the network protocols they use.

Table of contents

Introduction to network protocols

Deeper exploration into the world of inter-computer communications will reveal more and more types of communications (e.g. radio waves, Ethernet, Bluetooth, etc.), their interfaces and the network protocols they use.

From Techopedia, the term network protocols are defined as “formal standards and policies comprised of rules, procedures and formats that define communication between two or more devices over a network. Network protocols govern the end-to-end processes of timely, secure and managed data or network communication.”

The network that is referred to can either be a local area network (LAN) or the internet. Client or local devices are those requesting data and server or remote devices are those responding with data.

Understanding some common network protocols is written as short notes in an attempt to understand these protocols by comparing their similarities and differences.

Common network protocols

The common network protocols are HTTP, HTTPS, FTP, SCP, SFTP, FTPS and SSH.

HTTP (Hypertext Transfer Protocol)

Transferring files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web
Similar to HTTPS, but less secure
Uses TCP/UDP port 80
Used by web browsers (e.g. Chrome, Firefox, Edge, Internet Explorer), to display their content

HTTPS (Secure Hypertext Transfer Protocol)

Similar to HTTP, but ensures a secure connection using SSL encryption technology
Request and response data is secured using SSL certificates
Uses TCP/UDP port 443
Recommended as standard by Google search

FTP (File Transfer Protocol)

Network protocol supporting file transfers and manipulation capabilities between a client and server on a network
Uses TCP/UDP port 21
Restricted to FTP directory on server
FTP clients e.g. Eclipse IDE’s Remote System Explorer and Aptana Studio 3’s Remote Connection Manager

SCP (Secure Copy)

Network protocol supporting file transfers (only) between hosts on a network.
Part of SSH suite
Uses TCP/UDP port 22
E.g. WinSCP
Can copy file(s) anywhere you have the privilege to

SFTP (Secure File Transfer Protocol)

Similar to FTP, but ensures a secure connection
Part of SSH suite – uses FTP with an SSH tunnel between client and server
Similar to FTPS, but needs one port to transfer data
Uses TCP/UDP port 22
E.g. most FTP clients
Recommended over FTPS
FTP clients e.g. Eclipse IDE’s Remote System Explorer and Aptana Studio 3’s Remote Connection Manager

FTPS

Similar to FTP, but ensures a secure connection
SSL was applied to FTP to create FTPS
Similar to SFTP, but needs multiple ports to transfer data
FTP clients e.g. Aptana Studio 3’s Remote Connection Manager

SSH (Secure Socket Shell)

Network protocol that provides a secure way to access a remote computer by using username/password authentication
SSH also refers to the suite of utilities that implement the protocol
Uses TCP/UDP port 22
E.g. PuTTY & sshpass command

Other

These are not network protocols but are used with data transfers.

SSL (Secure Sockets Layer)

Security technology that provides a secure way for computers to establish an encrypted link between them
It is largely aimed at protecting the user’s privacy
E.g. HTTPS and FTPS
Used between web servers and web browsers
A web server requires an SSL certificate in order to create a Private Key and a Public Key
It is now called TLS

Notes on Raspbian (Linux)

On older versions of Raspbian SSH is automatically activated
SSH can be manually activated/deactivated using the raspi-config tool

Notes on OpenELEC / Kodi (Linux)

On OpenELEC, SSH must be enabled manually for the SSH protocol to be used

Conclusion

Inter-computer communications (e.g. radio waves, Ethernet, Bluetooth, etc.) work with interfaces and network protocols. Network protocols are the formal standards and policies comprised of rules, procedures and formats that define communication between two or more devices over a network. Here we listed and summarized a couple of network protocols.