Computer network is a very essential field of information technology. As far as it concerns now, communication between humans is the key to the civilization. And as technology grows on its verge, various networking devices are now used by people. Different technology used in computer networks has different roles to play in a network of computers. These devices work at different segments of a computer network and they perform different works. We know these networking devices by different names such as networking hardware, network equipment, networking components etc. Though all these names mean the same thing, they all have got different purposes. So let us show you some networking technology.
Hub is a very essential technology used in computer networks. A hub is used to connect multiple network hosts at a point. We use a network hub to do data transfer also. In computer networks the data is transferred in packets. So while transferring data, host sends a data in the form of packet to a network hub, hub copies the packet and sends it to all of its connected ports. All the ports receive the data and the port for whom the packet was sent claims the packet as its own. But a hub is not secure and safe to use because of this working mechanism. And the device is slow and congested because it’s technique of copying the data packets on all the interfaces. Hub is one of the basic components that we use as networking devices. Hub works at physical layer and connects networking devices together physically.
Hubs are usually used in those networks that use twisted pair cabling. They are designed to transmit the packets without altering any of them. They act as a road to direct electrical signals to right places.
There are two types of hubs:
Active Hub: Active hubs not only provide the way for data signals, they regenerate, strengthen and concentrate the signals before sending them to destinations. Active hubs are also called as repeaters.
Passive Hub: Passive hubs are more like contact point for the wires to built a physical network. They do not modify the signals.
- Ethernet Hub:
This device is same as hubs but it connects multiple Ethernet devices together and makes them work as a single unit. Ethernet hubs vary in speed measured in data transfer rate. They communicate in half-duplex mode where collision can happen at most of the times.
Same as a hub a switch also works at the physical layer. This is another key technology used in computer networks. But a switch is more intelligent in work than a hub. While hub just does the data forwarding, a switch filters and forwards the data which is a more intelligent way of dealing with the data packets than the hub. When a packet is received at one of the ports of the switch, it filters the packet and sends only to the interface that is identified as receiver. To do this, a switch also maintains a forwarding table. Switches are the linkage points of a network. Same as hub, switches are also connected to devices through twisted pair cabling. But the difference is hub works by sending the data to all the ports on the device where switch transfers data only to that port which is connected to the destination device.
Switch collects the MAC address of the devices connected to it. The transmission of data signals are well defined in a switch so the network performance is slightly enhanced. They operate in full-duplex mode. Devices can send and receive data from the switch at the same time simultaneously. Transmission speed in switches is double than the hub.
Bridge is a networking device that builds the connection between the bridge networks using the same protocol. Bridge is a device of data link layer. It connects different networks together and creates communication between them. It connects two networks of the same or different types which use the same protocol. Bridges are used to build up larger networks. Apart that, bridges are also used to divide larger networks into smaller segments. Bridge is a common technology used in computer networks. Bridge divides large networks by placing itself between two portions of two physical networks. And it controls the flow of the data between the portions. It has the ability to block the incoming data flow as well.
There are three types of bridges:
Transparent Bridge: This Bridge is transparent for the other devices on the network. The other devices do not know of its existence. It only does one job, blocks or forwards the data to the MAC address.
Source Route Bridge: This Bridge represents its name for the fact that the path of the packet through the network is implanted within the packet itself. Token ring networks use this Bridge.
Transitional Bridge: Transitional Bridge holds the process of conversion. It mainly converts the data format of packets as required to.
A router is a networking device that is responsible for routing traffic between networks. Router works as traffic police who directs various network traffics to their given directions. Routers connect various types of networks together and work as a gateman for data traffic. Routers are devices of the network layer. They are also identified as Layer- 3 devices of the OSI Model. Router collects and stores logical addressing information of the network header of a sent packet as IP Addresses. Routers are normally used by us to create larger and complex networks using complex traffic routing system. Same as bridges routers has the ability to connect different types of networks on the same protocol. It also can limit the flow of packet data broadcasts. Router is a common technology used in computer networks.
When a router receives data, it searches the address of destination by reading the header of the packet. Once a router gets the address, it searches the routing table to know how to reach the destination, and then forwards the packet to the route.
A repeater is an electronic device that is used to amplify the signal received by it. We can say, repeater is a device which receives a signal and re-transmits it using a higher level or higher power to provide the signal longer distance coverage. Repeaters work simply as an amplifier for the sent signal or data packet. It is a regular technology used in computer networks.
A gateway is a device used to connect multiple networks together and pass packets from one network to the other networks. A gateway acts as an actual gateway between different networking systems or computer programs. It is a device that creates a link between these networks. Gateways allow the computer programs to share data between them across the network through protocols either on the same computer or on different computers. A router can also be called a gateway, because it routes data from one network protocol to another.
Other devices as bridge convert the data into different forms between two networking systems. After that software converts the data from one format into another. Gateway is a very useful technology used in computer networks because it translates data formats. Gateways can be attached with other devices to use its data changing function.
- Network card:
Network cards are also known as Network Interface Cards. They are the hardware devices that connect a computer with its network. . Network cards are important hardware technology used in computer networks. Normally network cards are installed on the mother board of the computer. They are the device responsible for making a physical connection between the computer and the network. Data is translated into electrical signals by the computer and sent to the network via Network Interface Cards. These cards can also do some important data conversion. Network cards found these days are software configured. Unlike old versions, which needed drivers to configure them these are automatically configured.
- Network protocols:
Network protocols are a language of instructions for communication between the devices of the network. A computer with network must have one or more protocol drivers installed to run successfully. If there are two computers interconnected on a network, they must use identical protocols to communicate. Usually a computer is designed to use multiple protocols at a time. Protocols are not networking technology, but they are very essential for networking.
A Modem is a very interesting, useful and handy network device in our daily life. Modems are used everywhere now. Because of its usefulness and compatibility, it is used and loved by all of us. The word modem stands for two other words, modulator and modulator. That means, a modem simultaneously modulates and demodulates the signal at the same time between the digital data of a computer system and the analogue signal of a telephone line. A modem is a device which converts the digital signals generated by the computer into analog signals which can travel via phone lines to the destination. The modem can be used as a dial up for a LAN network or to connect to an ISP. Modems can be external device, as in the device which connects to the USB ports or the serial port of a computer. Or they can be proprietary devices for handheld gadgets and other devices. Modem can be internal device also in the form of add in expansion cards for computers and PCMCIA cards for laptops.