AT&T DS1/DMi/ISDN-PRI manual Zcs

GLOSSARY GL-21

unrestricted channel

unrestricted digital data

AB-channel that uses bipolar with 8-zero substitution (B8ZS) line coding and that does not have a ones-density requirement for user data. See also restricted channel.

User data that is presented to a transmission facility without having been encoded to prevent an all-0s octet. Unrestricted digital data requires that the transmission facilities use bipolar with 8-zero substitution (B8ZS) line coding on and end-to-end basis; otherwise the data will potentially be destroyed. Also called raw data.

user-to-userA capability that allows customers to send and receive user information

information transparently through an Integrated Services Digital Network (ISDN).

(UUI) exchange

user-to-user information transfer

U U I

via-net loss (VNL)

visual maintenance and administration panel (VMAAP)

V N L

voice-grade data

The transfer of special call-related information from the calling party to the called party during certain call setup and disconnect messages.

See user-to-user information exchange.

One of the components used in the assignment of connecting losses for tie-trunk links. Via-net loss (VNL) is calculated by means of a formula that factors in the temporal delay experienced by a signal as it traverses the link. Networks designed in this manner are called VNL networks.

A program running in the UNIX® operating system that emulates operations of the maintenance and administration panel (MAAP) used with a System 85 and DIMENSION ® PBX. VMAAP can be used interactively like the MAAP. It can also be called by another program. See also maintenance and

administration panel.

See via-net loss.

Data that is transmitted over a digital facility in analog form using pulse code modulation (PCM). The data must pass through a modem, either at both ends or at a modem pool at the far-end.

WATS (Wide	A service that allows calls to certain areas for a flat-rate charge based on
Area	expected usage.

Telecommunications

Service)

widebandMore than one channel used to support a particular application. For example,

channelsix 64K-bps bandwidth channels can be grouped together to provide one 384K- bps bandwidth channel.

	NOTE: Wideband channel arrangements are not permitted with System 85
	R2V4 phase 1.
X.25	A CCITT standard that specifies the interface between user data terminal
	equipment (DTE) and data circuit-terminating equipment (DCE). See also
	BX.25 and packet switching.
ZCS	See zero code suppression.