| |
|
B |
| Backbone |
 |
A LAN or WAN that interconnects intermediate systems
(bridges and/or routers). |
| Backplane |
|
The
main bus that carries data within a device. |
| Balun |
|
Balanced-unbalanced,
an impedance-matching device that connects a balanced
line (such as a twisted-pair line) with an unbalanced
line (such as a coaxial cable). |
| Bandwidth |
|
Measure
of the information capacity of a transmission channel.
Strictly speaking, bandwidth is the difference, expressed
in hertz (Hz), between the highest and lowest frequencies
of the channel. |
| Baseband |
|
Transmission
scheme in which the entire bandwidth, or data-carrying
capacity, of a medium (such as coaxial cable) is used
to carry a single digital pulse, or signal, between
multiple users. Because digital signals are not modulated,
only one kind of data can be transmitted at a time. |
| Baud |
|
Unit
of signal frequency in signals per second. Not synonymous
with bits per second since signals can represent more
than one bit. Baud equals bits per second only when
the signal represents a single bit. |
| BB-AS |
|
Broad-Band
Access Server |
| BB-RAN |
|
Broad-Band
Remote Access Node |
| BC |
|
Bearer
Channel |
| BCC |
|
Bearer
Channel Connection |
| BCC |
|
Black Check Character |
| B
Channel |
|
In
ISDN, a full duplex, 64 Kbps channel for sending data.
BCS Basic Combined Subset |
| BCU |
|
Baseband Channel Unit |
| Beacon |
|
Token ring frame signaling that the ring is inoperative
because of a serious hard error; defective cable or
faulty nodes are possible causes. |
| BECN |
|
Backward Explicit Congestion Notification |
| BER |
|
Basic Encoding Rule, rule for encoding data units described
in ANS.1; also, bit error rate, or the ratio of received
bits that are in error. |
| BER |
|
Bit
error rate, percentage of bits in a transmittal received
in error. |
| BGP |
|
Border Gateway Protocol, protocol for communications
between a router in one autonomous system and routers
in other ASs. |
| |
|
|
| Binaries |
|
Binary,
machine readable forms of programs that have been compiled
or assembled. As opposed to Source
language forms of programs. |
| Binary |
|
Characteristic
of having only two states, such as current on and current
off. The binary number system uses only ones and zeros. |
| Bisync |
|
Binary
synchronous communication, character-oriented data
link protocol for half-duplex applications. |
| BISDN |
|
Broadband Integrated Services Digital Network, communications
standard designed to handle high bandwidth applications
such as video over broadband. |
| Bit |
|
Binary
digit, the units - 0 or 1 - used in the binary numbering
system; the smallest unit of data processing information. |
| Bitronics |
|
Specification
for parallel printing which allows bidirectional communication
on a Centronics-type interface. Pioneered by Hewlett-Packard,
mainly used for postscript printers. |
| BITS |
|
Building
Integrated Timing System |
| BLES |
|
Broadband
Loop Emulation Service |
| BNC |
|
connector Standard connector to link IEEE 802.3
10BASE2 coaxial cable to a transceiver. |
| BOC |
|
Bell Operating Company, See RBOC. |
| BOD |
|
Bandwidth on Demand, feature that allows a remote access
device to initiate a second connection to a particular
site to increase the amount of data transferred to that
site to increase the desired threshold. The network BootP
Protocol that a network workstation uses on boot up to
determine the IP address of its Ethernet interfaces. |
| Boot PROM |
|
Programmable Read-Only Memory, nonvolatile memory that
contains information necessary for initializing a system.
Boot PROM information can be transmitted over a network. |
| Boundary |
|
Function capability of SNA subarea notes - encountered
most often in IBM 3745 high-speed communications controllers
- to offer protocol support for attached peripheral nodes. |
| BPA |
|
BackPlane Assembly |
| BPDU |
|
Bridge Protocol Data Units, a packet to initiate communications
between devices under a spanning-tree protocol. Compare
PDU.
Bps bits per second; units of transmission speed |
| Bps |
|
Bits
per second; units of transmission speed. |
| BRA |
|
Basic Rate Access |
| BRAS |
|
Broadband Remote Access Server |
| BRI |
|
Basic Rate Interface (2B+D) |
| BRI |
|
Basic Rate Interface, the ISDN interface comprising
two B channels and one
D channel. |
| Bridge |
|
A device that interconnects local or remote
networks no matter what higher level protocols (such
as XNS or TCP/IP) are involved. Bridges form a single
logical network, centralizing network administration.
They operate at the physical and link layers of the Open
Systems Interconnect (OSI) reference model. See SRT (source
routing transparent bridge), and STA (Spanning Tree Algorithm).
Contrast with router and gateway. |
| Bridge/router |
|
A device that can provide the functions of a bridge,
router or both concurrently. A bridge/router can route
one or more protocols, such as TCP/IP and/or SNX, and
bridge all other traffic. |
| Broadband |
|
A data-transmission scheme in which multiple signals
share the bandwidth of a medium. This allows the transmission
of voice, data and video signals over a single medium.
Cable television uses broadband techniques to deliver
dozens of channels over one cable. Contrast with baseband. |
| Broadcast |
|
A message forwarded to all network destinations. |
| Broadcast storm |
|
Multiple simultaneous broadcasts that
typically absorb available network bandwidth and can
cause network time-outs. |
| Brouter |
|
A device that routes specific protocols, such
as TCP/IP and IPX, and bridges other protocols, thereby
combining the functions of both routers and bridges. |
| BRS |
|
Boundary Routing System, an architecture that 3Com
software technology that permits simpler connection of
remote-office LANs to a central network site by centralizing
complex router functions. |
| BSC |
|
BISYNC,
Binary Synchronous Control
|
| Buffer |
|
Area
in a device for temporary storage of data in transit;
can accommodate differences in processing speeds between
devices by storing data blocks until they are ready
to be processed by a slower device. |
| Bus |
|
A
LAN topology in which all the nodes are connected to
a single cable. Allnodes are considered equal and receive
all transmissions on the medium. |
| Bypass
mode |
|
Operating
mode on ring networks such as FDDI and token ring in
which an interface has de-inserted from the ring. |
| Byte |
|
A data unit of eight bits |
| |
|
|
