INTELLINET NETWORK NSC15-WG User Manual - Manual (Page 60)

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Once you activate the multicast option, the screen will show
additional options:
Enter the address of your multicast server along with the
audio and video port. The Time-To-Live value defines how
long multicast traffic will expand across routers. Routers have
a TTL threshold assigned and only datagrams with a TTL
greater than the interface's threshold are forwarded.
Below are additional details regarding the differences between
Unicast and Multicast.
Unicast: For each connected
computer there is a separate
TCP/IP connection. When 20
computers are connected to
the camera, the camera has
to create 20 different
connections, and the camera
has to send out the same
video data to each of the 20 computers. This not only puts a
significant load on the camera, it also creates massive
amounts of data that need to be transferred over the network
to each connected client.
Unicast is still the most common model when using a network
camera, since most times only a recording device (DVR or
NVR) is connected to the camera and perhaps connections
from just a small number of computers.
Multicast: Here the initial stream is sent to the router only,
which creates optimal distribution paths for datagrams sent to
a multicast destination address. Whether one or 300 PCs are
connected to the video stream
does not matter. The
bandwidth and load of the
local camera is unaffected.
Because of this, multicast is
the preferred choice for
broadcast-type applications.