the default multicast broadcast settings are recommended for most interactive multicast broadcasting conditions. change them only after consultation with your system administrator (for example, if your organization has a firewall).

multicast broadcast properties are defined as follows:
bandwidth click the right arrow to select the maximum bandwidth
for the interactive multicasts. the actual bandwidth will
depend on the amount of available bandwidth during a
meeting.
video broadcast click the right arrow to select the video coding standard
format that all parties in the meeting are capable of using.
audio broadcast click the right arrow to select the audio standard that all
format parties in the meeting are capable of using.
broadcast to ip the destination ip address for an interactive multicast.
address all participants in the session transmit and receive from
this common ip address. this address must be a class d
address in the range of 224.0.0.0 to 239.255.255.255.
video port the id of the port used for the video connection.
video control the id of the port used for transferring control and
port synchronization information about the video
transmission.
audio port the id of the port used for the audio connection.
audio control the id of the port used for transferring control and
port synchronization information about the audio
transmission.
time to live the maximum number of routers that the packets sent
(ttl) from your system may pass through.