Types of Node Devices in a Computer Network: End devices and Intermediary Devices
We know a computer network is a term used to refer to any group (or system) of interconnected nodes (computers, printers, or any other devices) connected by communication links known as transmission media (or channels) usually meant for the exchange of information and resource sharing. In a computer network, a node is any device that is capable of sending or receiving data, to and from other nodes at definite and desired flow rates securely and reliably.
On the basis of functionality and usage, the node devices can be broadly classified into the following types –
- End Devices
- Intermediary Devices
End Devices :
End devices are the node devices that serve as a source point or a destination point in the communication that occurs on a computer network. With the coming advancements in computer networking systems, we have nodes that can act as a client, a server, or both. The rest of the network is built around these end devices to establish communication links between them. Software installed on the node devices determines the role they offer to play in a computer network. According to their usage, the end devices can be broadly grouped into the following categories –
- End Devices as Clients –
Perform the tasks of requesting data, displaying received data, etc. meant usually for the usage by end clients.
- End Devices as Servers –
Equipped with programs that provide information and services such as webpages or e-mails to other nodes (or hosts) on the network.
Functions of End Devices :
- They serve as the originator of the data or information that flows through the network.
- Act as an interface between end-users (humans) and the communication network having several node devices.
Examples of the End Devices :
Work Stations, Laptops, Desktop Computers, Printers and Scanners, Servers (File Servers, Web Servers), Mobile Phones, Tablets, Smart Phones, etc.
Intermediary Devices :
Intermediary devices are node devices that are designed to forward the data from one side to another side in a computer network. These intermediary devices work as a connecting medium (along with other services being offered) for other nodes and handle the tasks in the background ensuring that the data flows effectively at desired flow rates across the entire computer network.
The intermediary devices for the management of the data flowing through them use various addressing systems such as IP Address, MAC Address, and Port Numbers (or Port Address) along with the information about the network interconnections. Further various types of switching in the computer networks determine the path that messages take through the network during the communication.
Functions of Intermediary Devices :
- Signal damping is a common phenomenon that is overcome via regeneration and retransmission of the data signals done by these devices.
- To ensure successful transfers these devices keep record of information of source address, destination address or different pathways existing through the network depending upon the switching technique being employed.
- They also detect faults and errors effectively using redundancy bits, etc. and notify the devices to further ensure fault tolerance by performing corrections while transferring data in a computer network.
- Maintenance of a definite desired flow control and response timeout during the entire course of the communication.
- Setup, grouping and direction of messages (or packets) according to their priorities is done by these devices.
- Provide network security by permitting or denying the flow of data, based on security settings.
Examples of the intermediary devices :
Hubs, switches, wireless access points, and other devices used for accessing the network, file servers, web servers, print servers, modems, devices using for internetworking such as routers, bridges, repeaters, and security firewalls, etc.