Black Box 5000 manual 258

Multiserver 5000

KTS, key telephone system — In industry usage, a telephone system in which the telephones have multiple pushbuttons to allow users to select outgoing/incoming calls directly, without dialing an access number such as 9. Generally, a key telephone system has limited internal telephone-to-telephone capacity. As related to the Multiserver’s voice/fax module, a strapping option for compatibility with KTS-typetelephone-interface equipment.

LCD, liquid crystal display — An 80-character display in the front of the Multiserver unit that consists of two 40-character lines. It displays real-time status and alarm messages and the time of day, and by use of the adjacent keypad, it provides access to configuration, diagnostics, and administration functions. The LCD is standard on the Multiserver 5000.

leased line — A telephone line reserved for the exclusive use of the leasing customer without interexchange arrangements.

LF, line feed — A control character used to tell a terminal device to go to the next line.

line-sharing device — A device with the ability to differentiate between voice and fax signals. When voice and fax share the same channel, this device routes the output of the voice/fax channel either to the telephone interface or to the fax machine, as appropriate.

link — A communications circuit or transmission path connecting multiple points in a network, a composite. There are three types of link in the Multiserver:

An Interconnect Link connects two Multiservers, usually by an analog or digital circuit provided by the telephone company.

A Mux Link connects a Multiserver to a compatible multiplexor directly connected to the Multiserver, or remotely attached using a line driver, modem, or ISU.

An X.21 Link connects a Multiserver to a compatible multiplexer via a pay-as-you-go link. See X.21 bis.

local analog loopback — An analog loopback that forms the loop at the line side (analog output) of the local modem.

local channel loopback — A channel loopback that forms the loop at the input (channel side) of the local multiplexer.

local composite loopback — A composite loopback that forms the loop at the output (composite side) of the local unit.

local digital loopback — A digital loopback that forms the loop at the input (digital side) of the local modem.

loopback or loopback test — A type of diagnostic test in which the transmitted signal is returned to the sending device after passing through all, or a portion of, the data communications link or network. This allows the technician (or built- in diagnostic circuit) to compare the returned signal with the transmitted signal. This comparison shows whether the equipment and the transmission paths through which the signal traveled are working.

mark — In data communications, a binary 1 state, which is the steady, no-traffic state for asynchronous transmission.

modem — Contraction of MOdulator- DEModulator. A device that converts serial digital data from a DTE to a signal suitable for transmission over an analog telephone line, and converts the received signal to serial digital data for the DTE.

module — A printed circuit board and components with specific functionality that plug into one of the five module locations on the Multiserver.

module location — The chassis position of a module in the Multiserver. The CCM is in module location A, and there are four remaining module locations (B, C, D, and E) which can contain optional modules. The optional NMS module fits underneath the CCM and does not have a letter to indicate module location.

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