AT&T 75 manual Call Appearance, Voice Terminal, Callback Call, Central Office Codes, 11-2

CHAPTER 11. GLOSSARY

Call Appearance, Voice Terminal

On all multi-appearance voice terminals except the 7401 D, button labeled with an extension number used to place outgoing calls, receive incoming calls, or hold calls. Two lamps next to the button show the status of the call appearance or status of the call. (The 7401 D has two call appearances but does not have call appearance buttons with status lamps.)

Callback Call

A call that is automatically returned to a voice terminal user who activated the Automatic Callback or Ringback Queuing feature.

Call Waiting Ringback Tone

A low-pitched tone identical to the ringback tone except the tone decreases the last

0.2second. This tone notifies the attendant that the Attendant Call Waiting feature has been activated and that the called user is aware of the waiting call.

Central Office

The location housing telephone switching equipment that provides local telephone service and access to toll facilities for long-distance calling.

Central Office Codes

The first three digits of a 7-digit public network telephone number. These codes are numbered from 200 through 999.

Central Office Trunk

A telecommunications channel that provides access from the system to the public network through the local central office.

Class of Restriction (COR)

A number (O through 63) that specifies the restrictions assigned to voice terminals, voice terminal groups, data modules, and trunk groups.

Confirmation Tone

Three short bursts of tone followed by silence; indicates that the feature activated, deactivated, or canceled has been accepted.

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