Computer/Networking Glossary



Aluminum 6061-T6:
An aluminum alloy containing silicon and magnesium. Aluminum 6061-T6 has high tensile and yield strengths, is ideal for welding, and is often extruded into sheet form for use in aircraft, yacht and heavy-duty cabinet construction.


A facility (e.g. pathway, cable or conductors) between telecommunications closets or floor distribution terminals, or the entrance facilities and the equipment rooms within or between buildings.


Backbone Cable or Wire:
Cable or wire found in the backbone, see Backbone.


One binary (0 or 1) digit.


Cable Rack:
The vertical or horizontal open support (usually made of aluminum or steel) that is attached to a ceiling or wall.


Cubic feet per minute.


Central Office:
The location where common communications carriers terminate customer lines and house the switching equipment that interconnects those lines.


Closet, Telecommunications:
An enclosed space for housing telecommunications equipment, cable terminations and cross-connect cabling. A closet is the recognized location of the cross-connect between the backbone and horizontal facilities.


DDC (Display Data Channel):
A digital connection between a computer display and a graphics adapter that allows the display to communicate its specifications to the adapter.


Distribution Frame:
A structure that contains terminations for the connection of permanent cabling of a facility, in such a manner that interconnection or cross- connections can easily be made.


An Electronic Industries Alliance document, which outlines requirements for racks, enclosures and cabinets intended for the housing of servers and other network-related equipment.


Entrance Point, Telecommunications:
The point at which telecommunications conductors emerge through an exterior wall, a concrete floor slab, rigid metal conduit or intermediate metal conduit.


Entrance Room or Space, Telecommunications:
A space in which the joining of inter- or intra­ building telecommunications backbone facilities takes place. An entrance room may also serve as an equipment room.


Equipment Room, Telecommunications:
A centralized space for telecommunications equipment that serves the occupants of the building. An equipment room is considered to be different from a telecommunications closet because of the nature and complexity of the equipment housed in it.


Ethernet is a family of frame-based computer networking technologies for local area networks (LANs). The name comes from the physical concept of the ether. It defines a number of wiring and signaling standards for the physical layer, through means of network access at the Media Access Control (MAC)/Data Link Layer, and a common addressing format.

Ethernet is standardized as IEEE 802.3. The combination of the twisted pair versions of Ethernet for connecting end systems to the network, along with the fiber optic versions for site backbones, is the most widespread wired LAN technology. It has been in use from around 1980[1]. to the present, largely replacing competing LAN standards such as token ring, FDDI, and ARCNET. In recent years, Wi-Fi, the wireless LAN standardized by IEEE 802.11, is prevalent in home and small office networks and augmenting Ethernet in larger installations.

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The amount of floor space occupied by a server rack or enclosure.


The side-by-side connection of two or more server racks or cabinets.


Gigabit per second. A Gbps is 1 billion bits of data per second.


In data communications, a gigabit is one billion bits, or 1,000,000,000 (that is, 109) bits. It's commonly used for measuring the amount of data that is transferred in a second between two telecommunication points. For example, Gigabit Ethernet is a high-speed form of Ethernet (a local area network technology) that can provide data transfer rates of about 1 gigabit per second. Gigabits per second is usually shortened to Gbps. Some sources define a gigabit to mean 1,073,741,824 (that is, 230) bits. Although the bit is a unit of the binary number system, bits in data communications are discrete signal pulses and have historically been counted using the decimal number system. For example, 28.8 kilobits per second (Kbps) is 28,800 bits per second. Because of computer architecture and memory address boundaries, bytes are always some multiple or exponent of two.


GR-63 CORE Physical Protection deals with physical characteristics of the equipment. There are numerous tests involved in the compliance process for GR-63, some more severe than others.
The earthquake simulation is an example of a severe test. It simulates a 32-s time-history shock pulse created by Telcordia, with the shock response spectra (SRS) in the range of 5g at the base of the frame. The low-frequency portion of the time history produces displacements of approximately 10 in. peak-to-peak.
For the simulated earthquake, the unit under test (UUT) is mounted into a Zone 4 certified test frame, and the frame is configured to best duplicate the mass and stiffness of a fully loaded frame. Let's face it, the need to occupy every square inch of a rack in a CO is common. The 32-s time-history shock pulse then is performed and the excitation of the framework measured at both the middle and top of the frame.
Displacement at the top of the frame is measured relative to the base in inches and must not exceed 3 in. zero to peak. The UUT must be functional both before and after the test, with an objective for the unit to function during test.


Horizontal Cabling:
The wiring/cabling between the telecommunications outlet or connector and the horizontal cross-connect.


Horizontal Cross-Connect:
A cross-connect of horizontal cabling to other horizontal cables, backbone cabling or equipment.

Acronym for the International Building Code, an International Code Council standard which has been widely adopted throughout the United States.


Infrastructure, Telecommunications:
A collection of telecommunications components, excluding equipment, which together provide basic support for the distribution of all information within a building or campus.


A connection scheme that provides for the direct connection of individual cables to another cable or equipment cable, without a Patch Cord.


Interconnecting Cable/Wire:
The wiring between modules, units or the larger portions of a system.


Intermediate Cross-Connect:
A cross-connect between the first and second levels of backbone cabling.


A plug-in type terminal widely used for temporary connections.


An assembly of connector-less twisted pairs, used to join telecommunications circuits and links at the cross connect.


A point in a circuit where two or more wires are connected.

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A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. Typically, connected devices share the resources of a single processor or server within a small geographic area (for example, within an office building). Usually, the server has applications and data storage that are shared in common by multiple computer users. A local area network may serve as few as two or three users (for example, in a home network) or as many as thousands of users (for example, in an FDDI network).

LED Indicators:
LED indicators are used to display the status of the ports or switches. For example, they could indicate activity, power, connection speed or traffic scale.

MAC (Media Access Control):
The MAC address is a number used by network interface cards or adapters(NICs) to identify themselves on a LAN (local area network)


Megabit per second (Mbps or Mbit/s):
A megabit per second is a unit of data transfer rate equal to 1,000,000 bits per second. Because there are 8 bits in a byte, a transfer speed of 8 megabits per second (8 Mbps) is equivalent to 1,000,000 bytes per second (approximately 976 kB/s).


A device that sends and receives data signals over a common carrier's communication facility.


Modular Jack:
This term is outmoded; see Outlet/Connector, Telecommunications.


Modular Plug:
A telecommunications connector for wire or cords per the Part 68 Rules. A modular plug can have 6 or 8 contact positions, but not all the positions need be equipped with contacts.


Patch Cord:
A length of cable with connectors on one or both ends, used to join telecommunications links or circuits at the cross- connect.


Patch Cord Cable:
Bulk cable used in the manufacture of patch cords.


Patch Panel:
A cross-connect system of mateable connectors, which facilitates administration.


Powder Coat:
A solvent-free alternative to liquid paints, enamels and varnishes. Dry coating powder is electro statically applied to surfaces, then heat-cured so that it melts together and forms a smooth, hard finish. Powder coat is typically used on metals, such as extruded aluminum.

PCB (Printed Circuit Board ):
A board that contains layers of circuitry that is used to connect components to a system, includes items such as mother-boards and SIMMs, also referred to as Printed Wiring Board (PWB)

Port Trunking or IEEE 802.3ad:
A computer networking term which describes using multiple Ethernet network cables/ports in parallel to increase the link speed beyond the limits of any one singlecable or port.


A set of rules for communicating.

Q-in-Q VLAN for Performance and Security:
The IEEE 802.1 Q-in-Q VLAN Tag purpose is to expand the VLAN space by tagging the tagged packets, thus producing a "double-tagged" frame. The expanded VLAN (Virtual Local Area Network) space allows the service provider to provide certain services, such as Internet access on specific VLANs for specific customers, and yet still allows the service provider to provide other types of services for their other customers on other VLANs.


See: Cable Rack.


A color space system developed in 1927 mainly used to describe paint colors.

(Remote Network Monitoring) standard information used by network administrator to monitor and troubleshoot a LAN (local are network)


A network device, which handles the transfer of data between computers.


The acronym for Rack Unit. The amount of space in computer racks, cabinets and enclosures is measured in rack units; one rack unit is equivalent to 1.75 inches.


Web-browser, local terminal connection and Telnet remote terminal management make it versatile and easy for network administrator to manage the network remotely from any location or workstation.

Spannig Tree Protocol

Space, Telecommunications:
An area used for housing telecommunications closets and work areas.


Spanning Tree:
Network design to include redundant network circuits to provide a backup route if the primary path fails, and eliminate the problem of bridge loops.


Devices that filter and forward packets between LAN segments


Layer 2 Switches (The Data-Link Layer)
Layer 2 switches operate using physical network addresses. Physical addresses, also known as link-layer, hardware, or MAC-layer addresses, identify individual devices. Most hardware devices are permanently assigned this number during the manufacturing process.
Switches operating at Layer 2 are very fast because they only sort physical addresses, and don't look at the data packet very closely to learn anything more about where they are sent.

Telcordia GR-63-CORE:
A Telcordia Technologies document that gives standards for telecommunications housing/racking equipment in the areas of Fire Resistance, Earthquake/Vibration, Thermal Robustness and Airborne Contaminants.


Acronym for the Uniform Building Code.


UBC 1997:
The final edition of Uniform Building Code documents.

An unmanaged device can not be configured or managed over a network. This means that you do not need to set any details or to configure the device.


VSM (Virtual Stack Management):
Capability in multiple remote locations up to 20 kilometers apart can act as a single switch with one IP (Internet Protocol) address.


VoIP (Voice of Internet Protocol):
VoIP (voice over IP) is an IP telephony term for a set of facilities used to manage the delivery of voice information over the Internet.VoIP involves sending voice information in digital form in discrete packets rather than by using the traditional circuit-committed protocols of the public switched telephone network (PSTN). A major advantage of VoIP and Internet telephony is that it avoids the tolls charged by ordinary telephone service. VoIP derives from the VoIP Forum, an effort by major equipment providers, including Cisco, VocalTec, 3Com, and Netspeak to promote the use of ITU-T H.323, the standard for sending voice (audio) and video using IP on the public Internet and within an intranet. The Forum also promotes the user of directory service standards so that users can locate other users and the use of touch-tone signals for automatic call distribution and voice mail.
In addition to IP, VoIP uses the real-time protocol (RTP) to help ensure that packets get delivered in a timely way. Using public networks, it is currently difficult to guarantee Quality of Service (QoS). Better service is possible with private networks managed by an enterprise or by an Internet telephony service provider (ITSP). A technique used by at least one equipment manufacturer, Adir Technologies (formerly Netspeak), to help ensure faster packet delivery is to use ping to contact all possible network gateway computers that have access to the public network and choose the fastest path before establishing a Transmission Control Protocol (TCP) sockets connection with the other end. Using VoIP, an enterprise positions a "VoIP device" at a gateway. The gateway receives packetized voice transmissions from users within the company and then routes them to other parts of its intranet (local area or wide area network) or, using a T-carrier system or E-carrier interface, sends them over the public switched telephone network.


Wire Nut ® "A registered trademark of IDEAL Industries Inc for its brand of twist on wire connectors"
A closed-end splice that is screwed on instead of crimped.


Wiring Closet:
See Telecommunications Closet.


Zone 4:
A designation for the geographic areas most likely to be subjected to destructive seismic activity/earthquakes.


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