100-MBPS VOICE GRADE

(100VG) A "fast ethernet" standard. Uses the standard 802.3 Ethernet frame, has 96MBps throughput performance, uses node topology, allows up to 2000 meter cable runs with optical fiber (approx. 100m with UTP CAT-3 and -5, and STP). Because it can recognize two levels of priority (normal and high) in transmision requests, your most time-sensitive transmissions such as video can always have top priority. Data packets are transferred from node to node by a hub, based on the priority and the address of the data packet. See UTP, STP, and IEEE 802.3.

100BASE-F

Technology being developed to effect faster data transfer over existing cabling.

100BASE-FX

100Mbps - Fiberoptic used - segment length <=2000m

100BASE-T

Technology being developed to effect faster data transfer over existing cabling.

100BASE-T4

100Mbps - 4 pairs of UTP 3-5 - segment length <=100m See UTP.

100BASE-TX

100Mbps - UTP 5 (0.4 to 1.0 mm diameter) - segment length <=100m - network span <=210m See UTP.

100VG

See 100-Mbps Voice Grade.

100VG-ANYLAN

See 100-Mbps Voice Grade.

10BASE-2

Ethernet running on thin coax network cable, .188 inch diameter. Maximum segment 185 meters long with up to 30 nodes spaced at least 0.5 meter apart. Network span limited to 925 meters. Uses BNC "T" connectors for connections. (RG58 A/U or RG58 C/U), 50 ohm. Supports 10Mbps throughput using baseband transmission. Segment length limited to 200m. Sometimes called Thin Coaxial Cable, Thinwire, or Thinnet.

10BASE-5

Ethernet (802.3) running on Thickwire network cable. Maximum segment 500 meters long with up to 100 nodes attached. Nodes must be spaced multiples of 2.5 meters apart, and connections must be drilled, not cut, into the run. Usually used as a backbone for a system. Network span limited to 2500 meters. .405 inch diameter cable, with a bandwidth of 10Mbps utilizing baseband transmission on cable segments of 500m.

10BASE-F

Describes an optical fiber cable supporting 100Mbps of data throughput. An addendum to IEEE-802.3 is being prepared that describes optical transmission.

10BASE-T

Based on point to point topology with repeaters. Unshielded 8-conductor twisted-pair cable. While this cable is used with the Ethernet (standard 802.3) the physical medium specification widely used is EIA/TIA 568, which specifies cable characteristics and physical interfaces such as RJ45 modular plug terminations. Further broken down into categories based on throughput or bandwidth. Cheap and easy but has no noise immunity. Used primarily in office environments. Provides for 10Mb/s over twisted-pair telephone wire. Instead of using a bus where each station taps directly into the medium, each station taps into a concentrator which works as a hub to provide fault isolation and network diagnostics, as well as to propagate network traffic. Segment lengths are limited to 100m. This type of cable is used in star-type networks. 10BaseT does not support broadband transmission. 10Mbps - UTP (0.4 to 0.6 mm diameter) - segment length <=100m - Network span <=500m. See UTP, Level 1 Cable, Level 3 Cable, Level 5 Cable.

10BASEF-B

10Mbps - Fiber - segment length <=2000m Uses a synchronous protocol. For dark fiber and was pushed by a vendor for use on military submarines.

10BASEF-L

Data 10Mbps. Maximum length of 2 km between repeaters. Uses light (850, 1300, or 1550 nm) instead of electrical signals. Can be used with many types of network systems.

10BROAD-36

10Mbps - Coax (0.4 to 1.0 mm diameter) - segment length <=1800m - network span <=3600m

127.0.0.1

A loopback network connection. If you telnet, ftp, etc. to it you are connected to your own machine.

1575 VIRUS

The "green caterpillar" virus, infects a new file with every DIR or COPY command. Might display a green caterpillar that eats characters on the screen.

16-BIT

An adjective that describes systems and software that handle information in words that are 2 bytes (16 bits) wide.

1BASE-5

The last broadcast medium specified under the 802.3 specification. This specification was designed to provide for low cost LANs. The only medium used is unshielded twisted pair. 1Mb/s baseband - UTP (0.4 to 0.6 mm diameter) - segment length <=500m - network span <=2500m. See UTP.

23B+D

The Primary Rate Interface (PRI) in ISDN. A circuit with a wide range of frequencies that is divided into 23 64Kbps paths for carrying voice, data, video or other information simultaneously. See Primary Rate Interface.

2B+D

The Basic Rate Interface (BRI) in ISDN. A single ISDN circuit divided into two 64 Kilobits per second (Kbps) digital channels for voice or data and one 16Kbps channel for low speed data and signaling. Either or both of the 64Kbps channels may be used for voice or data. In ISDN, 2B+D is carried on one or two pairs of wires (depending on the interface) -- the same wire pairs that today bring a single voice circuit into your home or office. See Basic Rate Interface.

32-BIT

An adjective that describes hardware or software that manages data, program code, and program address information in 32-bit-wide words.

386MAX.SYS

A 386 expanded memory manager from Qualitas Corporation.

5ESS

A digital central office switching system made by AT&T.