Switching to VoIP

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Chapter 5: Enterprise Telephony Applications

without initiating a return call. For example, a voice mail message is received. The

receiving party must then make a call back to the sender in order to respond, if a

response is necessary.

Overhead Paging

Overhead paging is when an endpoint broadcasts the voice of the caller over a large

group of endpoints simultaneously. Most legacy overhead paging applications use

public address speakers or ceiling speakers wired to a power amplifier. This PA is

connected to an analog port on the PBX—the “paging channel”—and the PBX sees

the amplifier as an analog endpoint. Some PBX systems permit the use of TDM and

analog telephones to be used as broadcast endpoints, too.

Barging

Barging is similar to overhead paging, but instead of broadcasting the caller’s voice

over a large group of endpoints, the caller can send his voice to a single extension.

It’s called barging because this feature tends to allow callers to interrupt calls in

progress. Some PBX dialects call this feature announce.

Voice Mail

Voice mail is one of the most beloved telephony applications. Essentially, it records

voice messages on behalf of people who aren’t available to answer their calls. Practi-

cally everybody uses a form of voice mail, from the old-fashioned cassette tape answer- ...