Avaya Communication Manager Administrator's Manual page 351

The incoming multimedia call is answered in the normal manner by selecting the alerting call
appearance and going off-hook on the voice station. If the H.320 DVC system for the answering
party is configured for auto-answer, no other action is needed to complete the multimedia call. If
the H.320 DVC system for the answering party is not configured for auto-answer, the H.320
DVC system will alert and must also be answered by the user.
Note:
Avaya recommends, but does not require, that Enhanced mode complexes place
Note:
their desktop video system into an auto-answer mode of operation.
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 server, 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.
Enhanced Mode MM Complex
Issue 1 June 2005 351