Terms and Acronyms CO Central Office - The main building in a town (or towns) where all of the cables in the street come back to. In the CO is a telephone switch and hardware for handling high-speed digital lines. The CO has connections to the local telephone company's other COs, and to the long distance carriers' networks. Copper Catch-all term used to refer to cabling running from a CO to the customer's premise. Copper can be aerial cable strung from telephone poles or underground cable either buried directly in the earth or pulled through buried conduits. Does not include fiber-optic cables: fiber is fiber! CPE Customer Premise Equipment - Your network hardware that attaches to the carrier's network. Generally a router, bridge, channel bank, or CSU/DSU. It's thought by many to be common practice for lazy carrier techs to always blame problems on the CPE first. CLEC Competitive Local Exchange Carrier - A company that is competing aginst a traditional LEC for commerical or residential telephone business. CLECs are at a distinct disadvantage: the LECs own all the copper and the COs, new COs and facilities are tremendously costly to build, and the LECs have no compunction about using their monopoly power in the local telephone market to block the entry of CLECs into their turf. CLECs are a creation of telephone deregulation, a large part of the Telecommunication Reform act of 1996 (better known by the public for its infamous Communications Decency Act portion). Demarc The "demarcation point" where the carrier-owned facilities stop, and the customer owned facilities start. The box on the outside of your house where the SNET wires terminate is a demarc: everything between that box and your telephone is "customer owned", which makes your telephone or modem "CPE". FCC The Federal Communication Commission -- the FCC is the primary regulatory body in the US for all types of communications media and services. The FCC regulates everything from who uses what part of the electromagnetic spectrum, to how much children's programming a television station must put on each week. ISP Internet Service Provider - A company that provides connections to the global Internet. ISP services range from dialup modem connections to multi-megabit leased lines. ISPs range in size from tiny Mom and Pop operations to multinational mega-corporations like AT&T and MCI-WorldCom. Last mile, the "The last mile" is used to indicate the cabling from the CO to the customer premise, regardless of the actual distance. Most circuit problems are in the last mile. See also Local Loop LEC Local Exchange Carrier - The company which owns the local telephone wiring and provides telephone service (a.k.a. "dialtone"). LECs are RBOCs, RBOCs are LECs. Carrier technicians and corporate networking people refer to "the LEC". Management types and economic pundits talk about "RBOCs". Local loop, the The part of a telephone connection from the CO to you. The local loop, or just "the loop" got its name from the drip loop -- that little downward bow in an overhead telephone wire at the point where it attaches to your house. The drip loop is there to prevent rain water from following the overhead cable down the side of your house and then into your walls. Don't ask how, but the "drip loop" became the "loop cable" and then the "local loop". It has nothing to do with wires going out from, and then back to, the CO. PBX Private Branch Exchange - a telephone switch owned by a private concern (not a telco) for connecting calls between callers on their premise, and for connecting to the PSTN. PBXs range in size from a few dozen stations (telephones) to many thousands of stations. It is generally more efficient in terms of facilities (cabling) and rates to connect PBXs to long distance carriers via T1s than via individual copper lines. POP Point of Presence - the location where a carrier provides service from. Most of the major carriers have POPs in Hartford. Circuits between POPs will be carried on the carrier's network. Circuits extending from a POP to a customer location (eg: your office) will be carried on the LEC's cables. POTS Plain Old Telephone Service - The common analog telephone that has been installed in people's homes and businesses for over nintey years. PSTN Public Switched Telephone Network - The North American telephone system accessible to everyone with telephone service. This is in contrast to leased lines, or private voice networks. RBOC Regional Bell Operating Company - The local telephone companies that were created by the court-ordered breakup of AT&T (Ma Bell) in the 1970s. Southern New England Telephone Company (SNET or SNETCo), now owned by Southwestern Bell Company (SBC) is our RBOC. SLC or "slick" Subscriber Line Carrier - Generally seen as a large beige cabinet set on a concrete pad on the side of the road in areas where there has been substantial development of businesses or housing. A slick brings together regular analog telephone lines (POTS) and converts the signals to digital data. The digital signals are then multiplexed over a high-speed digitial circuit back to the CO where they are fed into the LEC's switch. This permits the LEC to provide a large number of new lines in an area without stringing new copper all the way back to the CO. As most new development is in outlying areas, this is a win for the consumer: your telephone line is only subject to distance related signal attenuation until it reaches the slick. From there the signal is carried as digital data with no loss of signal strength or clarity. This is good news if your new office is seven miles from the town's CO. The downside of having your phone service come through a slick, is that slick's require utility power to run. If the power goes out so will your phone service. At least, until a lineman can be dispatched to power the slick with the generator on his truck. Had enough yet? OK, we'll stop.
			[ CH 6 ] [ TOC ] 1999,2000 Shipman | Created 2-21-99 | Updated 2-6-00