Which of the following device is used to connect two LANs with different protocol?

Computer network consists of different devices such as router, hub, switch and others. Without these network devices data cannot be transmitted from one computer to another in a LAN or WAN network. These devices link up all the local and remote network segments with each other to make data communication from one segment to another. The two important devices of a big network are routers and switches. A computer network with good infrastructure with properly placed and configured network devices such as routers, switches etc. are helpful in reducing the overall operational cost, improve the performance, manageability and reliability.

6.3.1 Repeater:

A repeater is a network device that is used to retransmit the weaker signals in a network. A repeater receives the signals on the electromagnetic or optical transmission mediums. Repeater removes the unwanted noise from the incoming signals. A series of the repeaters is used to amplify the signals in the big network. The can also relay the messages between sub networks that use different protocols. Repeaters work at physical layer.

A hub is a networking device, which is used to connect the two segments of a wired network. In star topology, every computer is directly connected with the hub. In case of any fault in the hub, the data communication in the network computers stops. In an Ethernet (bus)-based networked a hub is a central device that is used to connect all the computers with each other.

A hub has multiple ports such as 4, 6, 8, 16 and 24 etc. when data packets are reached at hub. They are broadcasted to all the computers unlike a switch and only the destined computer receives the data. When you want to connect more than two computers with each other a hub or switch is required in a local area network. Hubs operate  at the physical layer.

6.3.3 Switch:

A network switch performs the same functionality in a network as a hub expect a different that switch does not broadcast the data packets o all the computers in a network like a hub. A network switch has multiple ports like 4, 8, 16 and 24 etc. All the computers in a wired network are directly connected with the switch through Ethernet cable. Switches limit the traffic to and from each port and all the devices connected to the switch has maximum available bandwidth. Switch doesn’t provide the built-in firewall capabilities like the routers. In the telecommunication and packet switched infrastructure switches play an important role. They transmit the data towards its destination based on the IP address. Switches work at data link layer.

6.3.4 Network Interface Card:

A network interface card is used to connect a computer to an Ethernet network. The card(shown in the figure below) provides an interface to the media. This may be either using an external transceiver mounted on the network interface card PCB. The card usually also contains the protocol firmware and Ethernet Controller needed to support the Medium Access Control (MAC) data link protocol used by Ethernet.

There is also a page showing examples of various types of networking equipment, include NICs for Ethernet.

9.3.5 Routers:

A router is a network communication device that is used to connect two or more logically and physically different networks. A router can be used to connect a LAN to LAN, LAN to WAN and LAN to internet. A router acts as a post office where sorting and distribution of the posts (packets in case of routers) is done. A router works on the basis of an IP address. Every router has built-in Operating System known as IOS. A router works on the network layer of the OS model and it routes the data towards the optimal path. Router uses the header information of the packets and forwarding table to define the best shortest possible path of the data.

6.3.6 Modem:

A modem is communication device that performs two different functions such as modulation i.e., it converts the digital data into analog and analog into digital. The faster types of the modems are used by the internet such as DSL modem and optical modems.

Internal modem:

A modem that resides on an expansion board that plugs into a computer.

External modem:

An external modem is a box that attaches to a computer’s COM port via cables.

ADSL modem:

ADSL stands for Asymmetric Digital Subscriber Line. It is a technology that allows copper telephone pairs to be used to provide a broadband connection. It provides ‘always-on’ Internet connection that is automatically established once the PC and ADSL modem are switched on.

Always-on means that the ADL broadband sets up a permanent connection to the internet that lets you access the internet as soon as you switch on the computer and the modem. You do not need to dial up like when you are using a standard modem connection. There will be no call charges for internet access but voice calls will be charged as before.

Which device is used to connect two LAN using same protocol?

Which device is used to connect two different protocols?

Which device is used to connect two different LANs?