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Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-From: Margo Reyna X-To: Sue Nord, Scott Bolton, Tracy Cooper, Lara Leibman, Donald Lassere, Mona L Petrochko, Barbara A Hueter, Jeff Dasovich, Susan M Landwehr, Marchris Robinson, Ricardo Charvel, Stephen D Burns, Xi Xi, Matthew Jachimiak, William Patrick Lewis, John Neslage, Gia Maisashvili X-cc: X-bcc: X-Folder: \Jeff_Dasovich_June2001\Notes Folders\Eci X-Origin: DASOVICH-J X-FileName: jdasovic.nsf Margo Reyna Regulatory Analyst Enron Corp., Government Affairs Phone: 713-853-9191 ----- Forwarded by Margo Reyna/NA/Enron on 01/19/2001 03:32 PM ----- djcustomclips@djinteractive.com 01/19/2001 03:31 PM Please respond to nobody To: 68460@WCTOPICS.djnr.com cc: Subject: Telecom Services: Competitive Local Exchange Carriers: Glossary of Communications Terms Glossary of Communications Terms 01/15/2001 PC Magazine from ZDWire Copyright © 2001 ZD Inc. All Rights Reserved. Attenuation The decrease in a signal's power from transmission to reception. The received signal is lower in power because of such factors as line resistance, distance and network configuration. Backbone The part of the network used as the main path for carrying traffic between network endpoints. CLEC (competitive local exchange carrier) An LEC that competes with the incumbent local exchange carrier (ILEC) in a given market. A company may be the ILEC in one market and CLEC in another. CO (central office) A telephone company facility serving a specific area. One or more phone lines run from a subscriber's home or office to a CO. Crosstalk Interference on analog lines created by cables that are too close together. Crosstalk may produce static, buzzing, or multiple conversations on one line. Digital loop carrier Equipment used to concentrate many local-loop pairs onto a few high-speed digital pairs or one fiber-optic pair for transport back to the central office. DLC systems reduce wiring cost. DOCSIS (Data Over Cable Service Interface Specification) A relatively new industry standard defining how cable modems communicate over cable TV lines. Any DOCSIS modem will work on any DOCSIS-compatible cable data network. DSL (digital subscriber line) A technology that provides high-speed, two-way data communications over analog phone lines. DSL operates on a higher frequency and doesn't interfere with existing phone service. The most widely deployed variety is ADSL (asymmetric DSL), which provides downstream speeds of 144 Kbps to 2.2 Mbps and upstream channels from 90 to 640 Kbps, depending on the distance from the CO. See HDSL, IDSL, SDSL, and VDSL. ELEC (enterprise local exchange carrier) A corporation operating as its own LEC to obtain better carrier rates. An ELEC may sell services to other carriers from a separate profit center. Firewall Software or hardware that filters or blocks traffic from a public or private network, preventing unauthorized or unrecognized access. G.Lite An ITU standard for DSL technology that delivers 1.5 Mbps downstream. Pronounced "gee-dot-lite." HDSL (high-bit-rate digital subscriber line) A flavor of DSL that delivers up to 1.544 Mbps of data symmetrically over two copper twisted-pair lines. The range of HDSL is limited to 12,000 feet; signal repeaters extend the service farther from the CO. Head end The cable company's main signal reception and distribution facility. The head end is the cable TV equivalent of a phone company CO, and all TV cables for a given area route back to a single head end. IDSL (ISDN digital subscriber line) A form of DSL providing a symmetrical speed of 144 Kbps over the copper wire provisioned for ISDN. Repeaters enable service up to 35,000 feet from the CO. ILEC (incumbent local exchange carrier) A LEC dominating the local market. IP address A numerical identifier for a device on a TCP/IP network. The IP address format is a string of four numbers, each from 0 to 255, separated by periods. ISDN (Integrated Services Digital Network) An all-digital replacement for analog telephone service. ISDN provides two 64-Kbps channels, called B-channels, over a single phone line, which can be used together or independently to carry voice or data. The data signaling channel, or D-channel, carries signaling and limited packet communications at either 16 or 64 Kbps, depending on the service. LEC (local exchange carrier A local telephone company. POTS (plain old telephone service) Standard telephony for placing and receiving calls. PPPOE (Point-to-Point Protocol over Ethernet) A protocol that allows DSL providers to meter connection time and to acquire a smaller, cheaper block of IP addresses. PPPOE changes DSL from an always-on to an on-demand service and lets providers reduce the size and cost of their Internet connection infrastructures. RBOCs (Regional Bell Operating Companies) The seven companies that were created after AT&T's divestiture in the mid-eighties. Also known as Baby Bells. SDSL (symmetric digital subscriber line) A form of DSL that transfers data upstream and downstream at symmetric rates of up to 2.3 Mbps over a single copper twisted-pair line. T1 A digital carrier technology used for transmitting data through the telephone system at 1.544 Mbps. T3 A digital carrier facility used for transmitting data through the telephone system at 45 Mbps. VDSL (very high data rate digital subscriber line) An evolving form of DSL that can deliver data at a rate of 13 to 52 Mbps downstream and 1.5 to 2.3 Mbps upstream over a single copper twisted-pair line. The operating range of VDSL is up to 4,500 feet from the CO. VOIP (Voice over IP) Software and hardware that allow voice signals to be carried over an IP-based network with POTs quality and reliability. VoIP segments the signal into frames, which are stored as voice packets. VPN (virtual private network) An authentication, encryption, and data-packaging technology that lets private network traffic travel over the public networks. VPNs provide remote offices and telecommuters with secure access to a corporate LAN or WAN. Because VPN traffic is encrypted, it cannot be deciphered as it travels over the Internet. WLL (wireless local loop) A broadband connection system that uses high-frequency radio links to deliver voice and data without the problems of gaining right-of-way for a fiber-optic cable installation or finding adequate copper connections for DSL. Also known as fixed-point wireless. Folder Name: Telecom Services: Competitive Local Exchange Carriers Relevance Score on Scale of 100: 66 ______________________________________________________________________ To review or revise your folder, visit Dow Jones CustomClips or contact Dow Jones Customer Service by e-mail at custom.news@bis.dowjones.com or by phone at 800-369-7466. (Outside the U.S. and Canada, call 609-452-1511 or contact your local sales representative.) ______________________________________________________________________ Copyright © 2001 Dow Jones & Company, Inc. All Rights Reserved
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