A LAN that transmits data at 100 megabits per second over copper cabling. It is a half-duplex version of 100Base-T that uses two twisted pairs of category 3, 4 or 5 UTP cable. Officially called 802.3y. See 100Base-T.
100 Mbps Ethernet implementation using four-pair Category 3,4, or 5 cabling. 100Base-T4 runs over four pairs, with three pairs used to transmit data at 33 MHz per pair in half-duplex mode. The fourth pair is used for CSMA/CD collision detection. 100Base-T4 uses the 8B6T encoding scheme for purposes of Clock/Data Recovery (CDR). See also 8B6T, 100Base-T, and CDR.
100-Mbps Ethernet implementation over Category 5 twisted pair cabling. The MAC layer is compatible with the 802.3 MAC layer. 100Base-TX requires Category 5 UTP ( Unshielded Twisted Pair) cabling, the type used in almost all new network installations. 100Base-TX uses two pairs of wire. One pair is used for transmission in half- duplex mode, and using the 4B5B Manchester encoding scheme used for data transmission. The other pair is used for receiving, and for signaling and control purposes. Upgrading a network from 10 megabits per second Ethernet to 100Base-TX requires 100Base-TX NICs and hubs as well as the Category 5 wiring to connect them. 100Base-TX is the best choice for interconnecting servers, hubs, switches and routers because it supports full duplex operation, meaning that it can simultaneously send and receive data. In addition, the cost and effort of upgrading these connections to Cat 5 is minimal since servers are often located very near these devices. See 100Base-T for a general discussion of this technology. See also 4B5B for discussion of the encoding technique.
100-Mbps baseband Fast Ethernet specification that refers to the 100BaseFX and 100BaseTX standards for Fast Ethernet over fiber- optic cabling. Based on the IEEE 802.3 standard. See also 100BaseFX, 100BaseTX, Fast Ethernet, and IEEE 802.3.
100-Mbps Fast Ethernet and Token Ring media technology using four pairs of Categories 3, 4, or 5 UTP cabling. This high-speed transport technology, developed by Hewlett-Packard, can operate on existing 10BaseT Ethernet networks. Based on the IEEE 802.12 standard. See also IEEE 802.12.
A standard for Gigabit Ethernet (GE) connectivity. 1000 means 1,000 megabits per second; Baseband means single-channel transmission; C means Copper; and X is the generic "whatever." The current specification calls for a very specialized copper cable in the form of an electrically balanced, shielded 150-ohm twinaxial cable which is limited to 25 meters in distance; the distance can be extended to 50 meters with a single repeater. Both conductors share a common ground in order to minimize concerns about safety and interference which could be caused by voltage differences. This cable is intended for use as a short jumper to interconnect clustered GE switches in wiring closets or computer rooms. Over time, the IEEE intends to develop a standard for 1000BaseCX connectivity over distances as long as 200 meters , but likely involving a much better form of copper; hence the X "whatever." See also 1000Base-LX, 1000Base-SX, Gigabit Ethernet, Twinax and UTP.
A 1-Gbps IEEE standard for Ethernet LANs.
A standard for Gigabit Ethernet (GE) connectivity. 1000 means 1,000 Mbps (Megabits per second); Baseband means single-channel transmission; L means Long-wave laser; and X is the generic "whatever." Long-wave lasers are more expensive than short-wave lasers, but can transverse longer distances as they use low-energy lasers over single-mode fiber at a wavelength of approximately 1,300nm (nanometers). For example, a long-wave laser system can transmit reliably over distances of approximately 3 kilometers through fiber with an inner core diameter of 5 microns; long-wave laser transmission also is supported over multi-mode fiber, and generally over longer distances than short-wave laser. See also 1000Base-CX, 1000Base-SX, Gigabit Ethernet and Fiber Optics.
A standard for Gigabit Ethernet (GE) connectivity. 1000 means 1,000 Mbps (Megabits per second); Baseband means single-channel transmission; S means Short-wave laser; and X is the generic "whatever." Short-wave lasers are less expensive than long-wave lasers, but cannot transverse the same long distances as they use high-energy lasers over multi-mode fiber at a wavelength of approximately 850nm (nanometers). For example, a short-wave laser system can transmit reliably over distances no farther than approximately 550 meters through multi-mode fiber with an inner core diameter of 50 microns; short-wave laser transmission is not supported over single-mode fiber. See also 1000Base-CX, 1000Base-LX, Gigabit Ethernet and Fiber Optics.
A standard for Gigabit Ethernet (GE) connectivity. 1000 means 1,000 Mbps (Megabits per second); Baseband means single-channel transmission; and X is the generic "whatever," which refers to the range of current and future transmission media. The IEEE 802.3z task force developed 1000BASE-X, which defines MAC (Media Access Control) changes, a Gigabit Media Independent Interface (hence the "X"), management and general requirements for Ethernet operation at 1000 Mbps, and a set of physical layer interfaces based on the original Fibre Channel technology. See also 1000Base-CX, 1000Base-LX, 1000Base-SX, Fibre Channel, and Media Access Control.
A 100 megabit-per-second LAN (Local Area Network) standard established by the IEEE 802.12 committee in 1996, and originally known simply as AnyLAN. A joint development of AT&T Microelectronics (now Lucent), Hewlett-Packard and IBM, VG=Voice Grade, meaning that voice-grade UTP (Unshielded Twisted Pair) generally is used as the transmission medium. AnyLAN means that LAN networking and internetworking can be accomplished, accommodating both Ethernet and Token Ring. 100VG- AnyLAN provides media flexibility, including Cat 3 (Category 3) UTP in a 4-pair configuration over distances up to 100 meters, Cat 4 UTP in a 4-pair configuration over distances up to 100 meters, and Cat 5 in a 4-pair configuration over distances up to 200 meters. Also accommodated are Level 1 STP (Shielded Twisted Pair) in a 2-pair configuration over distances up to 100 meters, and fiber optic cable (62.5 microns) over distances up to 2 kilometers. In a four-pair UTP configuration, all pairs are used for transmission in half-duplex mode, with the signal being split across the pairs at 25 MHz each. Data frames are encoded using the 5B6B encoding mechanism. 100VG-AnyLAN is deployed in a star topology, with up to five repeating hubs being tolerated. DPMA (Demand Priority Media Access) provides access priority and collisionless transmission, which is an improvement over Ethernet. 100VG-AnyLAN, however, requires equipment upgrade, which does not position it well relative to 100Base-T, also known as Fast Ethernet. See 100Base-T and FDDI for explanation of the competing 100-Mbps LAN standards. See also 5B6B.
Housing used to protect service wire splices.
The Feature Group D Carrier Identification Code (CIC). To connect with a long distance carrier in the United States other than your preselected carrier, as of July, 1998, you must now dial 101XXXX, where X is any number between 0 and 9. Each long distance carrier in the United States now has a unique four digit code represented by XXXX ” at least every carrier with Feature Group D access. That code is called a CIC code, which stands for Carrier Identification Code. AT&T's code is 0288. Thus, to reach AT&T you dial 101-0288, or as they advertise "Ten-Ten ATT." MCI's is 101-0222. There are two reasons for wanting to use 101XXXX to dial a different long distance to the one you're subscribed is simple ” to save money, or to use an other carrier when your preselected carrier is experiencing an overload or a network failure. You can dial some carriers (e.g. 101-0457) and receive the bill for your phone calls on your monthly bill from your 101XXXX LEC (local exchange carrier). Others you have to contact in advance and set up an account. Dialing via 101XXXX is a little complicated. Let's say you want to call my sister, Barbara, in Sydney, Australia from the U.S. You would dial 101-0457-011-612-9-663-0411 (the first seven digits are the CIC). As of July 1, 1998, this 101XXXX code replaced the original 10XXX. The reason 101XXXX replaced 10XXX is clearly that 10-XXX lets you dial only 1000 long distance carriers, while 101XXXX allows you to dial 10,000 long distance carriers. Deregulation and competition simply resulted in more carriers than could be accommodated by the old dialing scheme. In a very forward thinking move, the FCC has already planned for the next expansion, whenever needed, to 10XXXXX. This allows for up to 100,000 long distance carriers, while preserving the current CICs exactly as they are now. For more ” www.fcc.gov/Bureaus/Common_Carrier/FAQ/cic_faq.html. Kevin Ross, KevinR@seed-berry.com helped on this definition. Thank you. See also 950-XXXX.
10Base-2 is the implementation of the IEEE 802.3 Ethernet standard on thin coaxial cable. It's commonly called thin Ethernet or thinnet because the cable is half the diameter of 10Base-5 Ethernet cable. 10Base-2 LANs, which run at ten million bits per second, have their PCs daisy-chained along a terminated bus topology. The maximum segment length is 185 meters. Connectors are typically BNC. 10Base-2 uses RG58A/U 50- Ohm cable. Also called thinwire Ethernet.
A transmission medium specified by IEEE 802.3 that carries information at 10 Mbps in baseband form using bus topology, using 50-ohm coaxial cable and using AUI connectors. 10Base-5 was specified by the original Ethernet standards and is sometimes called ThickWire Ethernet. The maximum segment length (i.e. without a repeater) is 500 meters.
Standard for Fiber optic Active and Passive Star based Ethernet segments. Described in IEEE 802.1j-1993 (not in an 802.3 supplement, as you might expect). 10Base-F includes the 10Base-FL standards.
Part of the new IEEE 802.3 10Base-F specification, "Synchronous Ethernet" which is a special-purpose link that links repeaters and allows the limit on segments and repeaters to be enlarged. It is not used to connect user stations . See 10Base- F.
10 Mbps Baseband (single-channel transmission)-Fiber Link. A part of the IEEE Base-F specification that covers Ethernet over fiber over a distance of as long as two kilometers. 10Base-FL is interoperable with FOIRL. See 10Base-F.
An Ethernet local area network which works on twisted pair wiring (T stands for twisted pair) that looks and feels remarkably like telephone cabling. In fact, 10Base-T was invented to run on telephone cable. 10Base-T Ethernet local area networks work on home runs in which the wire from each workstation goes directly to the 10Base-T hub (like the wiring of a phone system), just like a phone system. 10Base-T cards which fit inside PCs typically cost the same as those for Ethernet running on coaxial cable. The advantages of 10Base-T (which has become the most commonly installed local area network in the world) are twofold ” namely if one machine crashes, it doesn't bring down the whole network (coax Ethernet LANs are typically in one long line, looping from one machine to another. One crash. Every machine goes down.); and secondly, a 10Base-T Ethernet network is easier to manage because the 10Base-T hubs often come with sophisticated management software. Though 10Base-T is designed to work on "normal" telephone lines, no one in their right mind would install "normal" phone wiring. The preferred method of installing 10Base-T networks is to use new Category 5 wiring. If you're forced (because you don't want to open up a pretty wall), then connect it to old phone cabling. It will probably work. Remember 10Base-T uses two pairs. Most phones need only one pair. 10Base- T's maximum segment length is 100 meters running on unshielded twisted pairs. See 802.3 10Base-T.
An IEEE 802.3 Ethernet LAN specification, 10Broad36 means ten million bits per second (10Mbps), Broadband, 3600 meter maximum segment length. In the LAN context, "broadband" means multichannel, which is accomplished over a coaxial cable system through FDM (Frequency Division Multiplexing). As FDM implies, the transmission method is analog, and the devices attach to the cable through modems, which almost defies the imagination for intensive LAN data transmission. However, analog transmission allows multiple communications channels (i.e., multiple transmissions) to be supported simultaneously. That is an advantage. The maximum segment length of 3600 meters is a real advantage, as well. The thick coax cable is a real disadvantage . 10Broad36 is seldom used. See 10Base-T, which is much more popular.
10 Gigabit Ethernet. Positioned as a high-speed technology for MAN (Metropolitan Area Network) applications, 10 GbE is a developing IEEE 802.3ae standard that will enable networks to scale from the traditional 10 Mbps beyond the common 100 Mbps and increasingly common 1 Gbps, up to 10 Gbps. 10GbE will enable MSPs (MAN Service Providers) to create very high-speed links between collocated equipment (e.g., switches and routers) at very low cost. 10GbE retains the basic protocol structure of Ethernet, including frame format, minimum and maximum frame sizes, and MAC (Media Access Control) protocol. However, 10GbE operates only in full-duplex mode, thereby making the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) MAC (Media Access Control) mechanism unnecessary, especially over longer distances.
10GbE employs an interface known as XAUI (pronounced "Zowie"), with "X" denoting the Roman numeral for 10, implying 10 Gbps, and "AUI" derived from Ethernet Attachment Unit Interface. The XAUI is an interface extender for the XGMII (10 gigabit Media Independent Interface), a 74-signal wide interface comprising one 32-bit wide data path for the transmit direction and one for receiving direction used to attach the Ethernet MAC (Media Access Control Layer) to the PHY (PHYsical Layer). The XAUI is a self-clocked serial bus evolved directly from the GbE 1000BASE-X PHY. The XAUI interface speed is 2.5 Gbps, and makes use of four serial lanes that operate in parallel over a WWDM optical fiber in order to achieve aggregate transmission speed of 10 Gbps. As is the case with 1000BASE-X, 10GbE employs the 8B/10B transmission code in order to ensure signal integrity through the copper circuitry of PCBs (Printed Circuit Boards ).
10GbE operates only over optical fiber media, unlike GbE, which operates at 1 Gbps over either copper or fiber. 10GbE will operate over SONET/SDH fiber, at the OC-192 speed of 9.953 Gbps, which is close enough to 10 Gbps to be acceptable. In a SONET/SDH mode, GbE makes use of SONET framing conventions and some inherent overhead functions. Some of the more costly aspects of SONET are unnecessary and will be avoided, including TDM support, performance monitoring, and certain network management functions. This "thin SONET" approach has been dubbed PES (Packet over Ethernet over SONET). 10GbE also will operate directly over optical fiber transmission systems based on WWDM (Wide Wavelength Division Multiplexing), a intermediate variation on the theme of WDM and DWDM (Dense WDM). WWDM specifies four serial optical channels that run in parallel. This WDM-based approach is known as PEW (Packet over Ethernet over WDM). Another approach is that of 10GbE over POF (Passive Optical Fiber), which has been dubbed PEF (Packet over Ethernet over Fiber).
Here's some additional detail on the PMD (Physical Media Dependent) sublayer of the PHY. MMF is intended to support 10GbE in serial mode over target distances up to 65m running at a wavelength of 850nm, and using WWDM at up to 300m running at 1310nm. SMF is intended to support 10GbE using either serial mode or WWDM at up to 10km running at 1310nm, and up to 40km in serial mode running at 1550nm.
10GbE is intended for backbone applications in the MAN domain, although it is considered extendible to the WAN domain, where it will be used to interconnect 10GbE MANs. It will be considered for application in the LAN domain, perhaps even directly to end-user systems (e.g., servers) in applications such as NAS (Network-Attached Storage) and SANs (Storage Area Networks). Ultimately, 10GbE may extend even to the desktop, although the latter requirement seems remote at this time. See also 10GEA, 1000BASE-X, CSMA/CD, DWDM, Ethernet, GbE, GE, MAC, MMF, PEF, PEW, PHY, POF, SMF, SONET, WDM, WWDM.
10 Gigabit Ethernet Alliance. Formed in January, 2000, the 10 Gigabit Ethernet Alliance was organized to facilitate and accelerate the introduction of 10 Gigabit Ethernet into the networking market. It was founded by networking industry leaders : 3Com, Cisco Systems, Extreme Networks, Intel, Nortel Networks, Sun Microsystems, and World Wide Packets. Additionally, the Alliance will support the activities of IEEE 802.3 Ethernet committee, foster the development of the 802.3ae (10 Gigabit Ethernet) standard, and promote interoperability among 10 Gigabit Ethernet products. See 10 Gigabit Ethernet. www.10gea.org.
The original access code that you dialed in North America to reach carrier that you had not equal access to. On July 1, 1998, the 10XXX access code was changed to 101XXXX. You must now dial the full seven digits. See 101XXXX for a full explanation.
China issues the first paper money.
The part of a 110-type cross connect, developed by AT&T (now Lucent), that terminates twisted-pair wiring and can be used with either jumper wires or patch cords to establish circuit connections.
A compact cross connect, developed by AT&T (now Lucent), that can be arranged for use with either jumper wires or patch cords. Jumper wires, used for more permanent circuits, must be cut down to make circuit connections. Patch cords allow ease of circuit administration for frequently rearranged circuits. The 110- type cross connect also provides straightforward labeling methods to identify circuits.
Japan's equivalent of the United States' emergency 911 number.
A bundle of 12 50-ohm coaxial cables that often run from a SONET carrier to a Digital Cross-Connect System (DCS), They carry a STS-1 (synchronous transport signal-1).
IEEE standard for connecting a PC's parallel port to a printer. Buy one that's advertised as bi-directional .
The average married woman in 17th-century America gave birth to 13 children.
The TV channel which Manhattan Cable uses to deliver cable modem services.
Serbs defeated by the Turks on the Field of Blackbirds. Prince Lazar, who led the Serbs, was reported to have said, "It is better to die in battle than to live in shame." The Serbian Church later made Lazar a saint .
Also called FireWire, IEEE 1394, 1394 and i.Link. 1394 is an IEEE standard for an data transport bus between a host computer and its peripherals. 1394 runs at speeds of 100, 200 and 400 Mbps, with increases planned up to 2 Gbps. A single 1394 port can support up to 63 peripherals, and a single host computer can support up to 1023 buses. The cable length can be up to 4.5 meters, although as many as 16 cables can be daisy- chained to extend the length to as much as 72 meters. A tree configuration also is acceptable. The cables comprise six conductors, and can supply up to 60 watts of power, allowing low-power peripherals to operate on a line- powered basis (i.e., without separate power). Much like USB (Universal Serial Bus), although running at much higher speeds and costing much more, 1394 supports plug-and-play on a hot-swappable basis. In other words, peripherals can be plugged and unplugged while the computer is turned on, and the computer will automatically discover and configure the link between itself and the peripheral device. Example peripherals include high-density storage devices, and high-resolution still and video cameras . 1394 supports both asynchronous and isochronous data transfer. Since 1394 is not a particularly exciting name , manufacturers have come up with their own names . For example, Apple Computer calls it FireWire. See also USB.
In writing about FireWire, Walt Mossberg of the Wall Street Journal, wrote:
FireWire, 1394, i.Link: These are three different, confusing terms for the same thing: a very fast connector on some PCs that can rapidly suck in and pump out large volumes of data from external devices, like camcorders, external hard disks and high-capacity portable music players. Apple, which helped invent the technology and has marketing in its bones, calls this connector "FireWire." The Windows PC makers use the geeky term "1394." To make matters a little more confusing, Sony calls the same connector "i.Link." This is worth buying only if you plan to import video or use a high-capacity music player like Apple's iPod.
The IEEE-1394 High Performance Serial Bus is a versatile, high-speed, and low-cost method of interconnecting a variety of personal computer peripherals and consumer electronics devices. The IEEE-1394 bus began life in 1986 as Apple Computer's alternative to the tangle of cables required to connect printers, modems, external fixed-disk drives , scanners , and other peripherals to PCs. The proposed standard (P1394) derived from Apple's original FireWire design, was accepted as an industry standard at the December 12, 1995 meeting of the Institute of Electrical and Electronics Engineers (IEEE) Standards Board. The official name is IEEE 1394-1995 Standard for a High Performance Serial Bus. The 1394 Trade Association was formed in 1994 to accelerate adoption of the Bus by personal computer and consumer electronic manufacturers. The 1394 Trade association has dubbed IEEE-1394 the MultiMedia Connection. Adaptec has licensed Apple's FireWire technology, trademark, and logo; FireWire is used interchangeably with IEEE-1394 in these pages.
The primary advantages of FireWire over other current and proposed serial buses are:
Versatility: FireWire provides a direct digital link between up to 63 devices without the need for additional hardware, such as hubs. Digital Video (DV) camcorders, scanners, printers, videoconferencing cameras, and fixed-disk drives all share a common bus connection not only to an optional PC, but to each other as well. FireWire is a candidate for the "Home Network" standard initiated by VESA (Video Electronic Standards Association) and other industry associations.
High speed: The present implementation of IEEE-1394 delivers 100 Mbps (Megabits per second) or 200 Mbps of data (payload) and control signals (over- head). Future versions that support 400 Mbps are in the development stage, and a 1.2 Gbps (Gigabits per second) version of IEEE-1394 has been proposed. Isochronous data transmission lets even the lowest -speed implementation support two simultaneous channels of full-motion (30-frame-per-second), "broadcast quality" video and CD-grade stereo audio.
Low cost: The cost of the integrated circuits and connectors to implement FireWire is often less than the cost of the connectors and circuitry it replaces . FireWire uses a flexible, six-conductor cable and connectors derived from Nintendo's Gameboy to interconnect devices. (A four-conductor version of the standard cable is used to interconnect consumer audio/video components .) Use of FireWire for consumer electronics gear, such as camcorders and VCRs, will provide the high-volume market needed to achieve low-cost implementation of FireWire on PCI adapter cards and PC motherboards. Ease of installation and use: FireWire extends Plug and Play features far beyond the confines of the personal computer. When you add a new device, FireWire automatically recognizes the device; similarly, on disconnect FireWire automatically reconfigures itself. The standard FireWire cable provides up to 1.5 amps of DC power to keep remote devices " alive " even when they're powered down. You don't need a computer to take advantage of FireWire; as an example, a VCR can act as a FireWire controller for camcorders, TV sets, receiver/ amplifiers , and other home theater components.
An IEEE data transport bus that supports up to 63 nodes per bus, and up to 1023 buses. The bus can be tree, daisychained or any combination. It supports both asynchronous and isochronous data. 1394 is a complementary technology with higher bandwidth (and associated cost) than Universal Serial Bus. Intel told me in summer of 1996 that it was supporting USB for most devices that attach to PC up through audio and video conferencing. Intel told that they are "supporting IEEE 1394 as the preferred interface for higher bandwidth applications such as high quality digital video editing, and connection to new digital consumer electronics equipment." according to Zayante, a company setting itself up as a testing lab for 1394 products, "The IEEE 1394 multimedia bus standard is the "convergence bus" bringing together the worlds of the PC and digital consumer electronics. It is already the digital interface of choice for consumer digital audio/video applications, providing a simple, low-cost and seamless plug-and-play interconnect for clusters of digital A/V devices, and it is being adopted for PCs and peripherals. The original specification for 1394, called IEEE 1394-1995, supported data transmission speeds of 100 to 400 Mbits/second. Most consumer electronic devices available on the market now support either 100 or 100/200 Mbits/second, meaning that plenty of headroom remained in the 1394 specification. But more devices are added to a system, and improvements in the quality of the A/V data (i.e., more pixels and more bits per pixel), lead to a need for greater bandwidth. The 1394a specification, currently in the final stages of approval (early 2000), offers efficiency improvements including support for very low power, arbitration acceleration, fast reset and suspend/resume features. The 1394b specification extends the 1394-1995 and 1394a efforts in three primary ways: It increases the speed to 800 Mbits/second and 1.6 Gbits/second, while adding the architectural infrastructure to support 3.2 Gbits/second and beyond; it specifies alternative media that allow 1394 products to be connected at distances of up to 100 meters (up from the 4.5 meters of the current specification); and it is overall more efficient, lower cost and easier to manage." See USB.