The other network devices are gateways, CSU/DSU, wireless access points, modems, ISDN adapters, proxy, firewall, multiplexer, digital media receiver, load balancers and the NIC adapter.
Each of these devices plays a specific role in a computer network and only the complex and the large network use all these devices. Being a network engineer or the systems administrator, you need to know the role and features of each device in your network.
Hub is a LAN networking device and every computer in an Ethernet based network is directly connected with the hub. All the computers that are connected to the network share the same bandwidth. When a hub receives the data packets at one of its port, it distributes the data signals to all the ports in a network.
When two or more computers try to send the data signals at the same time, a collision occurs and the process is known as Carrier Sense Multiple Access / Collision Detection. Hubs are usually come with the 4, 8, 16 and 24 ports. In the data communications, a hub is a place for the convergence where data arrives from multiple directions and forward to the multiple directions. The most advanced form of the hub is the intelligent or smart hub that contains the management software which is used to troubleshoot the most common problems.
Bridges are the networking devices that divided up the network into different segments to reduce the amount of traffic on each network. A bridge blocks and forwards the data packets based on their MAC addressees. Be blocking the unnecessary traffic to enter the other part of the network segments, it reduces the amount of traffic and the other issues such network congestions and the bottleneck. There are following three common types of the bridges.
A Transparent bride is invisible to the other part of the computer network and it performs the functions of blocking and forwarding the data packets based on the MAC addressees. They are the most popular types of the bridges.
Translation bridges are used to connect the two different networks such as Ethernet and Token Ring. It translates the data and forward to the other network.
Source-Route bridges are designed for the Token Ring networks. In the Source-Route Bridge, the entire route of the network frame is embedded into the frame.
A network switch is a LAN/WAN communication device. It joins the multiple computers together in the LAN and WAN. In the LAN, the switches do not broadcast the data to all the connected computers like the hub. Based on the IP/MAC addresses of the computer, a switch sends data only to the destined computer. Switches operate on the data link and network layers of the OSI layers model. Different models of the switches support the different number of the connected devices. In the LAN, switches support 10mbps 10/100 mbps or 100mbps data transmission speed. A switch conserves the bandwidth and offers the grater performance than the hub.
A router is a networking device that is used to connect the two or more logically and physically different networks. On the internet, the routers plays the functions of sorting and distribution of the data packets based on the IP addresses of the destination router or computer. Router use the header and forwarding table to choose the best shortest path to transmit the data towards the destination. A router is used to connect the two LANs, two WANs, and LAN with WAN and a LAN with the ISP network. Router uses the ISDN, frame relay, ATM and other communication technologies. A router operates at the network layer of the OSI model.