Point-to-Point Connections
In a point-to-point connection, a single T1 or FT1 link connects
equipment at two locations. In such a connection, the signal is not
reframed and the data link is not lost.
Polling
The task performed by a master Access-T when it requests data from
each of its enabled slave nodes.
Pulse stuffing
Pulse stuffing is the process of inserting pulses into the data stream
so that pulse density violations do not occur.
Quasi-Random Signal Source (QRSS)
A pseudo-random test pattern used to test looped or end-to-end T1
circuits. QRSS is a repeating pattern of 2
20
-1 bits which simulates
random “live” data and does not contain excessive zeros.
Robbed Bit Signaling
In voice applications, the use of the least significant bit in each DS0
in every 6th frame for signalling purposes. “Robbing” of these bits
has no significant affect on the quality of voice transmission.
Severely Errored Second (SES):
A second with 320 or more CRC errors or one or more Out-of-Frame
(OOF) conditions determines a Severely Errored Second. SES are not
counted while Unavailable Signal State is in effect. (See Figure B-1.)
Slave
The operation mode for an Access-T which is to be polled by a master
Access-T.
Station Clock
A centralized clock source available at the central office or other
location that provides a common clock source for equipment at that
office.
Superframe (D4)
D4 format employs a “Superframe” consisting of 12 frames of 193 bits
each (2316 bits total). In each frame, one framing bit is followed by 24
8-bit bytes. The pattern of framing bits is repeated every Superframe.
Framing requires 8 kbps, leaving 1.536 Mbps for user information.
Appendix B
ACST-0351-005
Glossary
June 1996
B-8