Hx1-Hx2 Manual-1.4.1 - Telos

A2 | appendix 1
ATA – see Analog Terminal Adapter.
B8ZS- Bipolar 8 (with) Zero Substitution. A T1 line coding method. This is the more modern
and most common line coding method of the two commonly available. See Line Coding, T1.
See also AMI.
Behind the PBX- This is our own term, and refers to when one privately owned phone system
is tied to another privately owned phone system. The most common application is when a key
system is connected to analog ports of a PBX. When it involves one PBX behind another, it is a
limited Tandem application. See Tandem Switch and Tandem Tie Trunk Switching below.
Bell Operating Company. See BOC. See also RBOC. Most often called “LEC’ (Local
Exchange Carrier) at the time of this writing. Few companies use the Bell name in the US any
longer, though it is used in Canada.
Bellcore- BELL Communications Research. See Telcordia. The research and development
organization owned by the RBOCs. Bellcore represents the RBOCs in developing standards for
Telco equipment and in testing equipment compliance to those standards. Bellcore also offers
educational and training programs open to all interested parties. Now Telcordia. See Telcordia.
BERT - 1) Bit Error Rate Test- A test for digital lines which involves looping a data path
and sending a test pattern. Data returning is compared to the sent data to check for errors.
Depending on the “Test Pattern” used, BERTs may or may not uncover problems. A line, which
only has occasional problems, will need a BERT of sufficient time duration to catch that intermittent
problem. A five minute BERT of an ISDN BRI circuit will only catch severe problems.
BERT - 2) Bit Error Rate Tester. The test equipment used to perform a Bit Error Rate Test.
Billing Telephone Number- The main phone number which all calls on hunt group or a PRI
are billed to. This information may be required when configuring a PRI PBX.
Bit Error Rate- The basic measure of errors on digital transmission paths. It is usually expressed
as the number of errors per number of bits.
Bit Error Rate Test-See BERT.
Bit Rate- The capacity of a digital channel. See Kbps.
BLEC- Building Local Exchange Carrier. A LEC who covers the occupants of a single building
(or a small group of buildings) only. Often Telecom services are provided by a BLEC as a
service or incentive to potential tenants. If a BLEC offers Long Distance Service it is covered by
the same regulations as any other LEC.
Blue Alarm- Also called an Alarm Indicating Signal (AIS). A keep-alive signal sent if a
problem occurs mid-span in a T-carrier system. The blue alarm signal is required because in
some cases T-1 repeaters will become unstable if inadequate 1’s density is not maintained.
BOC - Bell Operating Company. One of the regional telephone companies that were owned by
AT&T before divestiture in 1984 (i.e. New England Telephone, Ohio Bell, etc). The 22 BOCs
were divided among the RBOCs at divestiture. See RBOC.
Both Way Trunks- see combination trunks.
BTN- See Billing Telephone Number.
Business Office- The part of the phone company where you call if they mess up your bill, to
report problems, and to order service. Not necessarily technically literate.
Caller ID- A CLASS feature on an analog line that provides the number of the calling line as
a burst of FSK data (Bell 202 modem tones) following the first ring. Also called Calling Line
Identification. See also CLASS.