ANA-5910/5930/5940 User’s Guide
Stock Number: 510694-00, Rev. C Page: Glossary-4
Print Spec Number: 493081-00
Current Date: 5/28/97 ECN Date: 05/29/97
ANA-5910/5930/5940 User’s Guide
Glossary-4
adds the 5-byte header, then
transfers this 53-byt e ATM cel l
to the PHY Layer. Two different
formats are used to create the
ATM cell—one for the UNI and
one for the NNI. The UNI and
NNI cell headers are exactly the
same except that the UNI
replaces the first 4 bits of the VPI
field with a GFC field, which is
not used at this time.
ATM Switches
ATM switches are the heart of
ATM t echn olo gy. AT M sw itch es
initially set up the virtual circuit
for the end nodes to
communicate. Then they route
the incoming ATM cells using
the VPI/VCI numbers to the
appropriate outgoing VPI/VCI
and on to the respec tive node.
ATM switches are currently
designed with one of two
hardware standards: the ATM
backplane and the ATM matrix.
B
B-ISDN
Broadband Integrated Services
Data Network. A set of
standards under development
by the CCITT for services based
on ATM switching and SO NET/
SDH transmission.
Bandwidth
The amount of the channel you
want to use.
Best Effort
The transmission is sent using
the highest bandwidth available
to the driver. If you do not select
Best Effort, your data is sent
when all of the specified
requirements have been met.
Bridge
A device that connects two
networks of the same type
together. Bridges can usually be
made to filter traffic, that is, to
forward only certain traffic.
Broadband
A method of using the
transmission medium’s capacity
to provide multiple
communication channels (as
opposed to baseband, where the
entire capacity of the medium is
used for a single channel).
C
CBR
Continuous Bit Rate. Used for
real time services/data
transmissions that accept no or
very little delay of the output
signal. Video for instance is a
continuous bit rate service. See
Isochronous.
CCITT
Consultative Committee for
International Telegraph and
Telephone. An international
organization that develops
communication standards such
as Recommendation X.25.
Name recently changed to ITU
(International
Telecommunication Union).