Index - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z
OBJECT PROGRAM/OBJECT CODE - A computer program in its ready to use condition; the result of processing source code through assembler or compiler operations, sometimes called "compiled code"or a "compiled program."
OFFERED TRAFFIC - The volume of communications attempts in any specified period of time.
OFF HOOK - The condition occurring when a telephone is lifted from its mounting, allowing the hookswitch to operate. Synonymous with a "busy" line. British and CCITT English: Engaged; French and CCITT French: Occupe.
OFF LINE (OFF-LINE; OFFLINE) - 1.) Pertaining to terminal devices operating without being under direct control of a central control, as in teleprinter or data terminals preparing messages for later transmission while "off line;" 2.) Descriptive of terminal equipment not connected to a transmission line in any way. Example: An off line card reader or keypunch.
OFF-NETWORK ACCESS LINE (ONAL) - A local exchange (Feature Group access), Foreign Exchange, or WATS line connecting both incoming and outgoing traffic from a long distance company's network to the public switched network. Generally a circuit leased by a long distance carrier to be used by many customers not hooked directly into the long distance carrier's network.
OFF NETWORK CALLING - Telephone calls through a private switching system and transmission network which extend to the PSTN at a distant exchange; the subject of "Leaky PBX" discussion.
OFF PREMISES EXTENSION (OPX) - An extension telephone or keyset that is separated from the premises of its associated PBX (and source of "dial tone"; Inter- or IntraLATA, Inter- or Intrastate, or even international rates and regulation may apply.
ON HOOK - The condition occurring when a telephone handset is placed on its mounting, which causes the hook- switch to open its contacts. Synonomous with an "idle" line. British and CCITT English: Available; French and CCITT French: Libere.
ON LINE SYSTEM (ONLINE SYSTEM; ON-LINE SYSTEM) - A communicating system that requires a terminal to be in communication with and usually under control of a central point ... as in the case of a telephone set.
ON NETWORK CALLING - A term used to describe a call that originates and terminates within the limits and facilities of a private network.
OPERATOR ASSISTED CALLS - PSTN calls requiring manual intervention or assistance to complete; subject to increasing surcharges for the labor cost involved with providing assistance operators.
ORIGINATING OFFICE - The central office that serves the calling party.
OTHER COMMON CARRIER (OCC) - A long distance company other than AT&T having many of its own long distance circuits, either owned or leased. Some people use OCC to refer to all AT&T long distance competitors, including resellers, but this is not technically correct. The correct nomenclature has evolved into IEC for any communications common carrier operating across LATA boundaries.
OUT-OF-BAND - Any frequency outside the band used for information frequencies.
OUT-OF-BAND SIGNALING - 1.) In analog telephony, use of narrow band filters to restrict voice signals on a carrier channel below 3,400 Hertz, placing line supervisory signals in the region just above 3,400 Hertz. Common placements for the signaling tone are at 3700 Hertz; the CCITT R2 System places it at 3825 Hertz. 2.) In data and digital communications, using bit or character times not located in the terminal information transfer time slots; rather reserving time for such supervisory information in a special field, as in the T-1 ESF scheme for sending added information while eliminating "bit robbing" as done in earlier T-1s.
OVERBUILD - Adding capacity to a telecommunications transmission network by increasing the capacity of existing facilities.
OVERFLOW - Excess traffic on a particular route that is offered to another route for completion.
OVERRIDE - 1.) In telephony, seizure of a circuit even though it is already occupied; 2.) Other disciplines: Taking control in the presence of an automatic or remote control, modifying its operational decisions if necessary.