Polycom VIEWSTATION EX, User Manual

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Chapter 6 - Using Advanced System Features
© Polycom, Inc. 2003 185
endpoint at 128 Kbps. The 128 Kbps endpoint will be able send and
receive audio. It can also send video, but it cannot receive video. It
can only see its own video instead.
Note
To indicate that a particular endpoint which cannot downspeed at
the correct data rate is admitted to the multipoint call as an audio
call only, the ViewStation EX MCU displays a picture of a telephone
in the screen area corresponding to that endpoint call.
Downspeeding calls, either IP or ISDN, to allow another endpoint to
be added to an existing call (Dial-In Calling) is supported for mixed
protocol calls with systems that are capable of downspeeding. For
more information about inbound calls, refer to
Dial-In Calling
(Optional), on page 205 . For mixed protocol calls, see Mixed
Protocol Dialing, on page 192 .
For a 2 or 3-way conference, the maximum allowable downspeeding
rate is 256 Kbps for ISDN and 384 Kbps for IP. For a 4-way
conference, the maximum allowable downspeeding rate is 256 Kbps
for IP, and 128 Kbps if all calls are made using ISDN.
Downspeeding/Resynchronization Compatibility
Downspeeding or Resynchronizing with iPower
Your system has the ability to downspeed or resynchronize correctly
in an H.320 call with an iPower system and vice versa. The two
systems resynchronize the call if an ISDN line is lost during the call.
The call downspeeds in the event of a lower-speed, incoming call or
when necessary to add another outbound call to create a multipoint
conference.