Workstations within a network are attached to the network through wires. A network hub works as a central locations and can either be passive or active. The passive hub doesn't amplify the signals and transfers as it is. Active hub works as a repeater and amplifies the signal. Hubs send the received data to all the PCs or workstations attached to it. The data packet contains the information about destination PC. Though only the desired PC receives the packet but this increases the network traffic, making network more congested. Hub specifications include protocol, ports, and some other features such as mounting style.

Network Switch

The congestion problem associated with network hubs is overcome by the use of switches. A network switch sends the received information only to the desired PC or workstation. The ports are connected at OSI layer-2. The switch routs the packets between these ports deciding from the 48-bit MAC address associated with each packet.

Switch Specifications

A network switch specifications include its performance, form factor, ports, protocol, and its features. Performance is defined by data transfer rates, memory, and number of ports. Number of ports tells how many devices can be connected to the switch or a hub.

Network Switch / Hub Ports Configuration

Most common network switches or hubs are available with the following port standards. BNC, FireWire, GBIC, RJ-45, SC, MIC, ST, ISDN BRI S / T, ISDN BRI U, and Universal Serial Bus (USB).

Network Switch / Hub Protocol

Protocol specification is the most important thing to be considered while selection a network switches or hubs. The protocol not only specifies data communication's software attributes but also the data packet and information associated with it. Network hub or switches support number of protocols, which includes TCP /IP, IPX, Ethernet (10 Base-T, 10 Base-2, 10 / 100, fast, and Gigabit), ATM, CANbus, Frame Relay, ISDN, INTERBUS, Fieldbus, ControlNET, DeviceNET, SONET, PROFIBUS, Fibre Channel, FDDI, xDSL, and Token Ring.

Extra Features

Extra features that can be considered while selecting a switch or hub are mounting style, indicators, or extra space (memory). Stackable switches / hubs conserve space, indicators are mostly based on LEDs, and mounting style includes rack mount switches / hubs. Switches also come with two extra features. One is VPN connection support and other is full duplex mode. VPN connection occurs over a shared network and offers benefit of dedicated link. Full duplex support allows the switch to transmit information in both directions simultaneously. Moreover both the network switches and network hubs are essential for the larger networks. Hubs work as repeater providing data integrity whereas switches work as routers providing data security. So both can be used simultaneously. In a larger network with great deal of hubs, switches are used to divide the network in small groups of hubs.