Octel Unified Messenger Concepts & Planning Guide
GL-2 101-1620-005
Centum Call Second (CCS)
A unit of measurement for call time. The formu la for a CCS is the number of calls per hour
multiplied by their average duration in seconds, all mult ipli ed b y 100 . A CCS is 1/36 th of an Er lang.
Class of Service (COS)
A category used to determine a subscriber’s access to system options and features. The
administrator assigns a class of service to each subscriber.
DID
See Direct Inward Dialing.
Dial-by-Name
A method of addressing that enables a subscriber to spell the recipient's name on the telephone
keypad when using the telephone user interface.
Digital Meridian Integration Device (DMID)
A device that provides integration with Northern Telecom switches, such as the Meridian M-1. The
DMID physically sits between the PBX and the voice server and appears as one or two digital
telephones to the PBX, depending on the number of analog ports required. Analog line circuits for
the voice path appear on the digital set of the DMID. When a call is received on the DMID, it
simultaneously rings at the analog port. Th e DMID interprets the call display informat ion and
transmits it to the voice server which answers the caller with the appropriate personal greeting.
Direct Inward Dialing (DID)
Using DID, a caller can dial inside an organization to reach someone’s telephone extension directly
without going through a receptionist.
DMID
See Digital Meridian Integration Device.
Dual Tone Multifrequency (DTMF)
A combination of two tones that uniquely identify each button on a telephone keypad.
Erlang
A unit of measurement for call time. One Erlang is equivalent to 60 call minutes or 36 CCS. See
also Centum call second.
event
A significant occurrence in a voice mail system that is of int er es t t o an administrator for diagnostic
or reporting purposes.
fax routing address
A Microsoft Exchange e-mail address consisting of a string of digits that uniquely identify the
subscriber to the fax server.
Global System for Mobile Communications (GSM)
An audio encoding format with an encoding rate of approximately 13 kilobit per second.
Grade of service (GOS)
The probability, expressed as a percentage of callers who call during the busy hour, that an
incoming call is blocked (the caller hears a busy signal) because all ports are in use.
GSM
See Global System for Mobile Communications.