| 2B+D |
The way a Basic Rate ISDN line is configured,
using 2 B-channels and one D-channel. |
| 5ESS |
The name of central office equipment manufactured by
AT&T Lucent. |
| B-Channel |
A 64 kilobit-per-second bearer channel. |
| Bandwidth Allocation Control Protocol (BACP) |
The set of rules that manage bandwidth over PPP dynamic
multilink connections. |
| Basic Rate Interface (BRI) |
The standard ISDN line, consisting of 2 B-channels
and 1 D-channel. |
| Bridge |
A device that connects two or more networks and forwards
information between them. A bridge is sometimes called
a data link relay or a level 2 relay. A bridge is typically
simpler and less expensive than a router, but can only
carry limited information from one network to another.
|
| Central Office (CO) |
The telephone company's local facility that provides
telephone service in your area. |
| CENTREX |
A service provided by a central office that provides
a virtual PBX to a set of extensions. It offers features
such as transfer, conference, and forward within that
set of extensions. |
| Customer Access Line Charge (CALC) |
A federal tariff for hooking up your ISDN line. Also
referred to as an End User Common Line Charge (EUCL),
or Subscriber Line Charge (SLC). Every ISDN line is charged
one CALC or EUCL. The amount varies by state or province.
|
| Demarc |
The "demarcation point," or the point where
the telephone company's wiring stops and your wiring begins.
In other words, the phone company will charge you extra
for any wiring work performed on your side of the demarc. |
| D-Channel |
One of the three standard channels on a Basic Rate
ISDN line. At 16 kilobits per second, a D-channel can
carry signaling information and low-speed packet data.
|
| DMS |
The name of central office equipment manufactured by
Northern Telecom. |
| EWSD |
The name of central office equipment manufactured by
Siemens Stromberg-Carlson. |
| Exchange |
See central office. |
| Inside Wiring |
Wiring work that, in order for you to have an ISDN
line, may need to be done on your side of the demarc.
Typically, you have the option of doing it yourself or
having the phone company do it for an extra charge. |
| ISDN |
Integrated Services Digital Network: A completely digital
telephone/telecommunications network for carrying voice,
data, images, and video at high speed, by sending digitally-encoded
signals. ISDN provides "end-to-end" digital
service and can work on the copper wiring phone lines
that are in most homes and businesses, today. |
| ISDN Ordering Code |
A predefined number that tells the phone company how
to provision your ISDN line based on the requirements
of your ISDN hardware. |
| Line Extension |
A means for providing ISDN at distances beyond the
normal limit between the central office and your location.
|
| Line or Loop Qualification |
A test that your phone company runs to make sure that
your ISDN line meets the distance and quality requirements
of being within18,000 feet from the central office that
provides the ISDN service to you. |
| Multi-link PPP |
Allows you to combine two or more B Channels into a
single, faster PPP connection. With Multi-link PPP, you
could have a 128 kilobit/second PPP connection over a
Basic Rate ISDN line. |
| NI-1 |
(National ISDN-1) A specification for a "standard"
ISDN phone line. National ISDN 1 is intended to be a set
of standards which every manufacturer can conform to.
For example, ISDN phones that conform to the National
ISDN 1 standard will work regardless of the central office
the customer is connected to. Note: Future standards,
denoted as NI2 and NI3, are currently being developed. |
| NT-1 |
(Network Termination-1) The device that connects to
your ISDN hardware and works as a converter between an
ISDN U-interface and an ISDN S/T-Interface. Some ISDN
adapters have a NT-1 already built into them. This is
easier and less expensive than an external NT-1, but may
prevent you from connecting other equipment to your ISDN
line. |
| Northern Telecom DMS |
See DMS. |
| PBX |
Private Branch Exchange. A PBX is a private telephone
switch that provides switching (including a full set of
switching features) for an office or campus. PBXs often
use proprietary digital-line protocols, although some
are analog-based. |
| Point-to-Point Protocol (PPP) |
A protocol that allows a computer to use TCP/IP to
connect to other computers over a standard phone line,
using a high-speed modem. |
| POTS |
Plain Old Telephone Service: an analog (non-digital)
telephone line. |
| Primary Rate Interface (PRI) |
A type of ISDN service that offers 23 B channels at
64 kbs and one D channel at 64 kbs (23B+D). In Europe,
PRI provides for 30 B channels and two D channels (30B+2D).
See also: Basic Rate Interface. |
| Provisioning |
The combination of device and service options that
make up your ISDN line. You order your ISDN line, but
the telephone company provisions the line, (i.e., it configures
your ISDN service according to the physical capabilities
of the switch, as well as the options you choose.) |
| Router |
A device that connects two or more networks. A router
works like a bridge, but has greater capabilities than
a bridge. A router determines where the destination computer
is located, and then finds the best way to get there. |
| RJ-11 |
The most common telephone jack in the world, this is
a six-conductor modular jack wired with 4 wires. You probably
have RJ-11 jacks in your house. |
| RJ45 |
An 8-pin connector jack used with standard telephone
lines, and required by some ISDN hardware. A little larger
than an RJ-11 jack. |
| Service Profile Identifier (SPID) |
A number or set of numbers assigned to your ISDN line
by your phone company. In the U.S., one SPID is assigned
to each channel. The switch uses SPIDs as unique identification
numbers for each ISDN line, so it can determine where
to send calls and signals. S/T-Interface The part of the
ISDN line that connects to the computer or phone. |
| Switch Type |
The brand of equipment and software revision level
that the telephone company uses to provide you with ISDN
service. There are only a few types of switches in the
world and usually just one in countries other than the
United States. |
| Twisted Pair |
Another term for regular telephone wiring. Each telephone
"wire" is actually a pair of wires. U-Interface
A 2-wire ISDN circuit that connects the ISDN line to the
central office. The most common ISDN interface. |
| U-Interface |
A 2-wire ISDN circuit that connects the ISDN line to
the central office. The most common ISDN interface. |
