Administrator's Guide

Managing multimedia calling
555-233-506344 Issue 5 October 2002
If the originating party is providing a video signal, then a complete 2-way
multimedia call will exist. If the originating party is not providing a video signal,
the answering party will receive loopback video. The audio signal will exist at the
handset of the voice station. The audio signal may be moved to the H.320 DVC
system via activation of a
mm-pcaudio button on the voice station.
Hourglass Tone. The answering party may hear different things when the
incoming multimedia call is answered depending on the nature of the originator. If
the origination is directly from an H.320 DVC system or if the originator is an
Enhanced mode complex on a remote switch, an immediate audio path will not
exist between the two parties. This is because the H.320 protocol must be
established after the call is answered. It takes several seconds for the H.320
protocol to establish an audio path. During this interval the answering party will
hear special ringback. When the audio path exists the special ringback will be
removed and replaced with a short “incoming call tone” indicating that audio now
exists. The combination of special ringback followed by incoming call tone is
referred to as
“hourglass tone.” Hourglass tone is an indication to the answering
party that they should wait for the H.320 call to establish audio.
Early Answer. The answering party may administer their station in such a way as
to avoid hearing hourglass tone. If the station screen has set the
Early Answer
field to
y, then the system will answer the incoming multimedia call on behalf of
the station and proceed to establish the H.320 protocol. After audio path has been
established, the call will then alert at the voice station of the Enhanced mode
complex destination. The station may then answer by going off-hook and will
have immediate audio path. No hourglass tone will be heard by the answering
party.
- multiple call appearance operation
With an Enhanced mode complex all calls to or from the complex are controlled
via the voice station. Each voice or multimedia call has its own call appearance
which may be selected without regard for the nature of the call using the specific
call appearance. This allows a multifunction station to control multiple voice or
multimedia calls in exactly the same way they would control multiple voice calls.
As an example, a user may originate a simple voice call on the first call
appearance. A multimedia call may then arrive on the second call appearance. The
user activates HOLD on the first call appearance and selects the second call
appearance to answer the multimedia call. The user may then activate HOLD on
the second call appearance and reselect the first call appearance or select a third
call appearance and originate another call.