ADTRAN 1204002L2, TSU IQ+ user manual Telnet

Appendix D. Glossary

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.

61200275L1-1 TSU IQ+ User Manual D-13