Network test equipment is used to test, probe, and analyze telecommunication, network, and telephone systems. Many different types of network testing equipment are available. Examples include breakout boxes, bit-error rate (BER) testers, network analyzers, and local area network (LAN) analyzers. Breakout boxes are multiconductor devices used to test and monitor signals such as timing signals, data signals, and control signals. Bit-error rate testers are devices or procedures that measure the BER for specific transmissions. Typically, this value is expressed as ten to a negative power so that, for example, a BER of BER of 10-9 means that for every Gigabit transmitted, one bit is sent or received in error. Network analyzers and local area network (LAN) analyzers monitor traffic on a network. This network test equipment collects information about packet sizes, the number of packets, error packets, overall usage of a connection, the number of hosts and their media access control (MAC) addresses, and details about communications between hosts and other devices.
Network test equipment includes products such as protocol analyzers, telephone testers, tone tracers and tone generators. Protocol analyzers capture all of the traffic on a medium, parse the data according to the rules of installed network protocols, and display the results. Examples of network protocols include asynchronous transfer mode (ATM), Ethernet and its many variants, fiber distributed data interface (FDDI), Fibre Channel, frame lay, front panel data port (FFDP), integrated services digital network (ISDN), point-to-point protocol (PPP), serial-line Internet protocol (SLIP), and synchronous optical network (SONET). Protocol analyzers for T1 lines, TCP/IP connections, and RS232, RS422 and RS485 communications are also available. Telephone testers are network test equipment for telephone lines and telecommunications systems. They are often sold as kits or modules. Tone tracers are used to monitor and trace the tone in telecommunication lines. Tone generators produce the tone in telecommunication systems.
Network test equipment differs in term of form factor, interface port, features, and regulatory compliance. Choices for form factor include hand held, notebook, desktop, rack mount unit, integrated circuit (IC) or chip, and printed circuit board (PCB). There are many choices for interface port, including Bayonet Neil-Concelman (BNC), IEEE 1394 or FireWire® (Apple Computer, Inc.), G.703, G.704, parallel, RJ-45, RS232, RS422, RS485, universal serial bus (USB), V0.24, V.35, x.21, and X.31. In terms of features, some network test equipment has a remote control port, a printer port, visual indicators, external clocking, or customized pattern testing. Wireless network test equipment is also commonly available. In terms of compliance, network test equipment that is destined for sale in European Union (EU) nations should comply with both the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE) directives.