Digi 90031300 Manual Do Utilizador
T1 Modem Bank
84
network
a collection of links, nodes, and computers that provide connections between two or more defined points
to facilitate telecommunication between them.
off-hook
the modem is in use, and the activity light is on.
PCM (Pulse Code Modulation)
the standard digital voice format, at 64K bps;
POP (Point-of-Presence)
the point within a local TELCO where the subscribers’ circuits for leased-line or long
distance dialup circuits are terminated.
PPP (Point-to-point protocol)
a communication link in which two stations are directly connected. PPP allows for
TCP/IP connections over serial lines and serial devices such as modems.
Private or leased lines
refer to a permanent circuit between endpoints over which data is transmitted. Private or
leased circuits are available from providers of WAN digital communications. T1 lines can be supplied by the
provider to include private or leased circuits and others such as switched lines.
provider to include private or leased circuits and others such as switched lines.
Protocol
a set of rules or standards designed to enable computers to connect with one another and exchange
information with as few errors as possible.
PSTN (Public Switched Telephone Network)
Robbed bit signaling
a bit in the data stream used for signaling
switched line
a single-circuit line connection between two points on a switched network. This is usually a
connection made as a result of dialing via the phone system, as opposed to a permanent leased line.
TCP/IP (Transmission Control Protocol/Internet Protocol)
a set of network services that provides interoperability
between heterogeneous systems. The TCP portion is responsible for providing reliable and recoverable
communications between two end points. The IP portion sets up the routing used by TCP to transmit.
communications between two end points. The IP portion sets up the routing used by TCP to transmit.
TELCOS
TELephone COmpanies
T1
a digital transmission method for multiplexing multiple voice and/or data channels over a system of copper
wire cables with amplifiers or regenerators that reinforce the digital signal at intervals of about one mile. T1 offers a
two-way connection at 1,544,000 bits per second. One T1 line carries a DS1 circuit, the equivalent of 24 port
connections running at 64K bps. Depending upon the provisioning by the carrier, both leased channels and switched
channels may be combined. Point-to-point dedicated T1 lines provide only permanent circuits. Switched T1 lines
commonly use in-band signaling for call management, resulting in switched 56K bps channels.
two-way connection at 1,544,000 bits per second. One T1 line carries a DS1 circuit, the equivalent of 24 port
connections running at 64K bps. Depending upon the provisioning by the carrier, both leased channels and switched
channels may be combined. Point-to-point dedicated T1 lines provide only permanent circuits. Switched T1 lines
commonly use in-band signaling for call management, resulting in switched 56K bps channels.
UART
(
Universal Asynchronous Receiver/Transmitter)
a device that performs asynchronous communication
functions by converting parallel digital output from a DTE device into serial bit transmission and vice versa.
virtual circuit
a communications link that appears to be a direct connection between sender and receiver,
although the link can physically involve routing between a more circuitous path.
Wide-Area Network (WAN)
a network composed of systems that are relatively far apart, meaning that the area
is usually gauged in hundreds of miles. A WAN may also encompass a series of LANs connected over a wide area.
In this manual, WAN refers to a network consisting of lines provided by telephone companies.
wink start
in placing a call, the T1 Modem Bank goes off-hook, then waits for a wink acknowledgment before
dialing.