ADTRAN 1200275L1, Руководство пользователя

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Appendix D. Glossary
61200275L1-1 TSU IQ+ User Manual D-13
synchronizing bits (sync bits)
A fixed pattern in synchronous transmission used to identify the boundaries of
frames.
synchronous
Communications in which the timing is achieved by sharing a single clock. Each
end of the transmission synchronizes itself with the use of clocks and informa-
tion sent along with the transmitted data.
T1
A digital transmission link with a capacity of 1.544 Mbps. T1 uses two pairs of
normal twisted wires. T1 normally can handle 24 voice conversations with each
conversation being digitized at 64 kbps. With more advanced digital voice
encoding techniques, it can handle more voice channels. T1 is a standard for
digital transmission in North America. It is also called T-1.
TELNET
The standard TCP/IP remote login protocol specified in RFC-854.
transmission
The dispatching of a signal, message, or other form of intelligence by wire, radio,
telegraphy, telephony, facsimile, or other means. A series of characters, mes-
sages, or blocks including control information and user data. The signalling of
data over communications channels.
T-span
A telephone circuit or cable through which a T1 carrier line runs.
UAS
unavailable seconds. An unavailable second (UAS) state is declared at the onset
of ten consecutive severely errored seconds (SES). The UAS state is cleared at
the onset of ten consecutive seconds with no SES.
VT 100
A non-intelligent terminal or terminal emulation mode used for asynchronous
communications. Used to configure the TSU IQ+.
yellow alarm
When the local CSU is in a red alarm condition, it sends a bit pattern (in-band in
SF, out-of-band in ESF) towards the network to tell the carrier and the far-end
CSU that there is a problem in the receive direction.