Cisco Cisco TelePresence MCU 4510 Maintenance Manual
Managing conferences
Cisco TelePresence MCU 4.3 Product administration guide
Page 58 of 242
Per-participant parameters
Content contribution
Content contribution refers to the ability of video conferencing devices to contribute the content channel
video for a conference via the mechanism of opening a separate video channel, distinct from its
video for a conference via the mechanism of opening a separate video channel, distinct from its
main
video
stream. Specifically, this section does not deal with the use of content by the MCU when sending
content channels to viewing devices or the use of other protocols such as VNC to supply the content channel
video for a conference.
video for a conference.
For a conference configured with content channel video enabled, each endpoint in that conference is either
permitted or prohibited from being able to contribute content video. H.239 is the protocol used by H.323 video
conferencing endpoints to supply or receive content channel video; BFCP is the protocol used by SIP video
conferencing endpoints to supply content channel video. Other content channel source configurations , such
as the use of a
permitted or prohibited from being able to contribute content video. H.239 is the protocol used by H.323 video
conferencing endpoints to supply or receive content channel video; BFCP is the protocol used by SIP video
conferencing endpoints to supply content channel video. Other content channel source configurations , such
as the use of a
VNC connection
, do not depend on any H.239 or BFCP contribution parameters.
Remember that what is termed Content contribution is more precisely described as the ability to start
contributing content channel video via H.239/BFCP. The nature of the H.239 and BFCP protocols used
between the MCU and endpoints is such that once an endpoint has successfully become the content source
for a conference, the MCU is not then able to force that endpoint to stop contributing the content channel
video.
contributing content channel video via H.239/BFCP. The nature of the H.239 and BFCP protocols used
between the MCU and endpoints is such that once an endpoint has successfully become the content source
for a conference, the MCU is not then able to force that endpoint to stop contributing the content channel
video.
While an endpoint is supplying the content channel for a conference, it is considered to be holding the virtual
content tokenfor the conference. This token must be relinquished before either another endpoint can start
contributing video via H.239 or BFCP or a content channel source such as VNC become active. This token is
normally released by a specific endpoint operation (e.g. a "stop content " option), or by that endpoint leaving
the conference. However, when Automatic content handover is enabled, the MCU will ask the endpoint (or
computer) to return the token if there is another participant who wants to start contributing content.
content tokenfor the conference. This token must be relinquished before either another endpoint can start
contributing video via H.239 or BFCP or a content channel source such as VNC become active. This token is
normally released by a specific endpoint operation (e.g. a "stop content " option), or by that endpoint leaving
the conference. However, when Automatic content handover is enabled, the MCU will ask the endpoint (or
computer) to return the token if there is another participant who wants to start contributing content.
When Automatic content handover is enabled, it allows another participant to start sending content without
having to wait for the current content provider to stop sending content from his computer. In this case, the
MCU will start sending the 'new' content to the participants in the conference and will ask the endpoint (or
computer) that was originally providing content to return the token. Automatic content handover is a unit-
wid/blade-wide configuration option on the
having to wait for the current content provider to stop sending content from his computer. In this case, the
MCU will start sending the 'new' content to the participants in the conference and will ask the endpoint (or
computer) that was originally providing content to return the token. Automatic content handover is a unit-
wid/blade-wide configuration option on the
Settings > Content
page.
By default, participants' ability to contribute content video (technically, as above, to start contributing H.239
or BFCP video) is determined by the per-conference Content contribution from endpoints setting
(
or BFCP video) is determined by the per-conference Content contribution from endpoints setting
(
Conferences > Add new conference
).
The per-conference default Content contribution from endpoints setting can be overridden by individual
endpoints' configuration. If such an endpoint's Content contribution setting is <use conference default> then
the endpoint's ability to contribute content channel video will be determined initially from the conference
setting. If the endpoint setting is <enabled> or <disabled> then this will override the conference setting and
that endpoint will either always be prevented from using content, or always permitted (assuming the
conference of which it is part is configured with content channel support). As well as being part of each
endpoint's configuration, the Content contribution setting can also be specified when calling out to an
endpoint by address.
endpoints' configuration. If such an endpoint's Content contribution setting is <use conference default> then
the endpoint's ability to contribute content channel video will be determined initially from the conference
setting. If the endpoint setting is <enabled> or <disabled> then this will override the conference setting and
that endpoint will either always be prevented from using content, or always permitted (assuming the
conference of which it is part is configured with content channel support). As well as being part of each
endpoint's configuration, the Content contribution setting can also be specified when calling out to an
endpoint by address.
Irrespective of per-conference or per-endpoint configuration parameters, if a conference is configured to allow
content channel operations then it is possible to explicitly enable or disable individual conference
participants' ability to use content via the web browser interface (assuming a user login with
content channel operations then it is possible to explicitly enable or disable individual conference
participants' ability to use content via the web browser interface (assuming a user login with
).