ClearOne Digital Media - Manual (Page 69)

HDCP Keys
HDMI with HDCP was created as a consumer technology to enable point to point secure
transfer or transmission of high quality digital content such as HD, and it was never intended
to be used in large multi-source and multi-display (zone) applications required by modern
residential or commercial AV projects. This means, too many devices in a signal path is
destined to create problems with the display of audio and video content.
HDMI source devices all have a limit to the number of downstream devices they support.
This limit is determined by the number of available HDCP keys in the device. All HDMI
sources that utilize HDCP limit the number of devices which may be connected at one
time. For this reason an important aspect of HDCP for all AV designers and installation
professionals is the use of “keys” which HDCP utilizes to manage handshaking between
devices.
The HDCP specification states the maximum depth (number) of devices between source
and display is six (6). This means connecting too many displays or video devices will cause
the source to stop outputting a signal without warning in most HDMI switching systems.
However, a unique feature of StreamNet is that the system actually provides user guidance
to the user of options available in an extended condition and provides choices, compared to
simply shutting off the stream without warning or explanation as most other HDMI switching
or digital transmission solutions would do.
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pg 69 StreamNet Digital Media and System Design Reference Guide
Solving Digital Media Related AV Problems