Carrier Access Access Navigator user manual Definitions

Glossary

Definitions

3DS0 Mode

4:1 TDM Mode

10Base-T

Alarm

Indication

Signal

Alternate Mark Inversion

Asymmetrical

Digital

Subscriber Line

Attenuation

Basic Rate

Interface

Bellcore

Bipolar with 8-Zero Substitution

An ISDN BRI termination method that connects three DS0s to an ISDN BRI port, one for each B and D channel. This mode is very simple but not as efficient as the 4:1 mode. It works with non-GR-303 switch interfaces, using fixed connections for the B and D channels.

An ISDN BRI termination method that connects 2.25 DS0s to an ISDN BRI port, one for each B channel and 0.25 for the D channel by multiplexing four D channels onto one DS0. This mode can efficiently carry 4 BRI ports using only 9 DS0s. It works with GR-303 switch interfaces, using a fixed connection for the D channel and dynamically connecting the two B channels when needed.

The IEEE 802.3 standard for operating Ethernet local area networks (LANs) at 10 Mbps data rates. 10Base-T uses twisted-pair cabling (such as conventional phone wires) to connect network elements to a wiring hub or router.

AIS. Also known as a “Blue Alarm Signal” or “All Ones Keep Alive,” an AIS is an unframed all ones bit pattern sent by equipment at the far end to indicate that an alarm condition exists upstream in a circuit leading to the downstream equipment. Keep-alive signals are required by the network facilities to prevent oscillation of the line repeaters which causes interference (cross-talk and bleeding) within adjacent channels.

AMI. A line-encoding format used in bipolar DS1 (T1) transmission systems whereby successive ones (marks) are alternately inverted in polarity. This is the traditional method of line encoding used with voice signals. B8ZS coding is preferred for data signals because AMI does not preclude long strings of zeros from entering the public network from the DTE in violation of the pulse density requirements mandated in Part 68 of the FCC Rules and AT&T Publication 62411.

ADSL. See description of Symmetrical Digital Subscriber Line (SDSL)

Reduction of signal magnitude or increased signal loss, usually expressed in decibels (dB).

BRI. See Integrated Services Digital Network Basic Rate Interface.

Bell Communications Research. See Telcordia.

B8ZS. A line-encoding format used to avoid long strings of zeros in a bipolar DS1 (T1) signals entering the network from the DTE. Every string of eight zeros is replaced by a special code (token). The code contains a pattern of bipolar

GlossaryGlossaryGlossaryGlossary-4 August 2003 Access Navigator - Release 1.8