Routers and Switches are hardware devices that are used in connecting servers, computers, networks, and other such data traffic handling devices. Routers are box-type devices that are small and have a number of ports at the front and the back faces. These ports have connectors and are used to provide connections to different computers and servers, to electrical circuits to divert power, and also in display illumination circuits where a number of LEDs and lights are used for decoration or to display the status of a machine or process. A router is used to direct TCP/IP packets to other networks and the session is active till the packet reaches the target destination. The data packet also has the IP address of the destination.
The devices are placed between two LANs or WANs, at gateways, or between a LAN and the ISP. Routers use protocols such as ICMP for communication. Routers examine the data packet to understand the IP addresses of the source and the destination, then route the packets as needed to ensure the data reaches its final destination. There are different types of routers such as broadband routers used in home networks for connecting the home computer and LANs to the Internet and also allow a single Internet connection to be shared between multiple computers. These routers also provide proxy support and DHCP server along with integrated firewalls. Other types are wired Ethernet broadband routers that have an in-built Ethernet switch and permit multiple hubs and switches to connect. Wi-Fi wireless routers are also available and they are used to provide wireless network connectivity between computers and the Internet (Schudel, 2008).
A switch is a hardware device that is used to connect more than one computer or server in a LAN. A switch functions at the Data Link Layer of the OSI model. These devices can operate with virtually any type of protocol. A switch stores records of the MAC addresses of all computers and servers that are connected to it. Switches are more intelligent and conserve bandwidth as they examine the data frames to resolve the MAC addresses of the source and destination devices and allow data to be transmitted when there is no congestion. It is able to resolve and identify the exact port number to which the data is to be sent connects to the port and starts the data transfer only when the port is free, ready to accept the traffic, and is able to understand the protocol. Another advantage that a switch provides is that it allocates the full bandwidth to each of the connected devices, provided the network can handle the load. Different types of switches are network switches and Ethernet switches. Each switch can have eight or more inward and outward connections and network administrators typically connect multiple switches in a daisy chain so that the switching capacity is incrementally increased. These devices are designed to support 10 Mbps, 100 Mbps, or 10/100 Mbps Ethernet standards (Seifert, 2000).
Routers and Switches are specified as per parameters such as Number of Ports, maximum data transfer speed, total memory of the network equipment, protocols allowed, IP Addressing, Hardened Product specifications for military and aircraft applications to withstand extremes in climate, and others. Devices are available that can offer speeds from 64 Kbps to more than 2 Gbps.
References
Schudel Gregg. 2008. Router Security Strategies: Securing IP Network Traffic Planes (Networking Technology: Security. Cisco Press. ISBN: 9781587053368.
Seifert Rich. June 27, 2000. The Switch Book: The Complete Guide to LAN Switching Technology, i Edition.. Wiley Publications. ISBN-13: 978-0471345862.