Multitech RouteFinder MTASR2-203, User Manual, Page: 83 / 90

Glossary
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Local Loop: A transmission path, typically twisted-pair wire, between an individual subscriber and the nearest public
telecommunications network switching center. The wires provide ISDN service, but require an NT1 at the user end and an
LT at the network end. (AKA, “loop” or “subscriber loop”.)
Logical Link Control (LLC2): In a local area network, the protocol that governs the exchange of transmission frames
between data stations independently of how the transmission medium is shared. The LLC2 protocol was developed by the
IEEE 802 commitee and is common to all LAN standards.
Logical Unit (LU): A type of network accessible unit that enables end users to gain access to network resources and
communicate with each other.
Long Haul: The T1 element that connects to the Access portion of the long distance company’s (LDC’s) central office.
The LDC is commonly called the point of presence (POP). Each LDC has a number of POPs, located throughout the
country. The LDC is also called an IEC (Inter Exchange Carrier).
Long Haul Communications: The type of phone call reaching outside of a local exchange (LE).
M
Management Information Base (MIB): A database of network management information used by the Common
Management Information Protocol (CMIP) and the Simple Network Management Protocol (SNMP).
Megacom: An AT&T service with a normal WATS line (typically T1) between the customer premise and the AT&T serving
class 4 CO are the customer’s responibility.
MegaLink: BellSouth’s leased T1 service.
Message: Associated with such terms as packet, frame, and segment. 1. In information theory, an ordered series of
characters intended to convey information. 2. An assembly of characters and sometimes control codes that is transferred
as an entry from an originator to one or more recipients.
Modem: A communications device that enables a computer to transmit information over a phone line. It converts the
computer’s digital signals into analog signals to send over a phone line and converts them back to digital signals at the
receiving end. Modems can be internal and fit into an expansion slot, or external and connect to a serial port.
Multiplexer (Mux): 1. A device that takes several input signals and combines them into a single output signal in such a
manner that each of the input signals can be recovered. 2. A device capable of interleaving the events of two or more
activities or capable of distributing the events of an interleaved sequence to the respective activities. 3. Putting multiple
signals on a single channel.
Multiprotocol: A device that can interoperate with devices utilizing different network protocols.
RouteFinder: A secure gateway that provides multiple LAN users with high performance Internet access by functioning
as a TCP/IP RouteFinder that resides on the outer edge of a firewall.
Multithreading: The ability of a software system to be able to handle more than one transaction concurrently. This is
contrasted to the case where a single transaction is accepted and completely processed befor the next transaction
processing is started.
N
Nailed Connection: A permanent or dedicated circuit of a previously switched circuit or circuits.
Nailed-up Circuit: A semi-permanent circuit established through a circuit-switching facility for point-to-point connectivity.
NAK (Negative Acknowledgment): Communications code used to indicate that a message was not properly received,
or that a terminal does not wish to transmit. Contrast with ACK.
Network: A group of computers connected by cables or other means and using software that enables them to share
equipment, such as printers and disk drives to exchange information.
Node: Any point within a network which has been assigned an address.
O
Object-Oriented: A method for structuring programs as hierarchically organized classes describing the data and
operations of objects that may interact with other objects.
Office Channel Unit - Data Port (OCU-DP): The CO channel bank used as the interface between the customer’s DSU
and the channel bank.
Off-hook: The condition of a device which has accessed a phone line (with or without using the line). In modem use, this
is equivalent to a phone handset being picked up. Dialing and transmission are allowed, but incoming calls are not
answered. Contrast “on-hook”.