| A | B |
|---|
| Main distribution facility | Primary communications room for a building. Central point of a star networking topology where patch panels, hub, and router are located. |
| horizontal cross connect | Wiring closet where the horizontal cabling connects to a patch panel which is connected by backbone cabling to the main distribution facility. |
| Main cross-connect. (MCC) | Wiring closet that serves as the most central point in a star topology and where LAN backbone cabling connects to the Internet. |
| ICC | IDF that connects the horizontal cross-connect to the main cross-connect |
| patch panel | An assembly of pin locations and ports which can be mounted on a rack or wall bracket in the wiring closet. Patch panels act like switchboards that connect workstations cables to each other and to the outside. |
| backbone cabling | Cabling that provides interconnections between wiring closets, wiring closets and the POP, and between buildings that are part of the same LAN. |
| Catchment areas | Zone that falls within area that can be served by an internetworking device such as a hub. |
| normal mode | Term used to describe problems between the hot and neutral wires on a power line. |
| sag | Any decrease of below 80% in the normal voltage carried by a power line. A sag is sometimes referred to as a brownout |
| surge | Any voltage increase above 110 % of the normal voltage carried by a power line. |
| spike | Any power impulse lasting between .5 and 100 microseconds and possessing an amplitude over 100 % of peak power line voltage. |
| Point of presence (POP) | Point of presence is the point of interconnection between the communication facilities provided by the telephone company and the building's main distribution facility. |
| common mode | Term used to describe problems involving either the hot or neutral wires and the safety ground wire on a power line. |
| router | Network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information |
| cut sheet | A rough diagram indicating where cable runs are located and the numbers of rooms they lead to. |
| backoff | The retransmission delay enforced when a collision occurs. |
| Logical bus topology | Linear LAN architecture in which transmissions from network stations propagate the length of the medium and are received by all other stations. Use by Ethernet. |
| collision | In Ethernet, the result of two nodes transmitting simultaneously. The frames from each device impact and are damaged when they meet on the physical media |
| collision domain | In Ethernet, the network area within which frames that have collided are propagated. Repeaters and hubs propagate collisions; LAN switches, bridges and routers do not |
| gutter | Type of wall-mounted channel with removable cover used to support horizontal cabling. Gutter is big enough to hold several cables |
| hierarchical star topology | Extended star topology where a central hub is connected by vertical cabling to other hubs that are dependent on it. |
| noise | Undesirable communications channel signals. |
| raceway | Wall-mounted channel with a removable cover used to support horizontal cabling. |
| signal injector | Device used to measure attenuation of a signal on a network. |
| star topology | LAN topology in which end points on a network are connected to a common central switch by point-to-point links. |
| telepole | Telescoping pole with a hook at one end. It is used to get cable across a ceiling or attic quickly. |
| tie-wraps | Plastic ties used for holding cables together or for holding cables in place. |
| wire map | Feature provided by most cable testers. Used to test twisted pair cable installations, it shows which wire pairs connect to what pins on the plugs and sockets. |
