VIVOTEK
User's Manual - 73
Multicast settings for stream 1, 2, and 3: Click the items to display the detailed configuration
information. Select the Always multicast option to enable multicast for stream 1 or 2.
Unicast video transmission delivers a stream through point-to-point transmission; multicast, on the
other hand, sends a stream to the multicast group address and allows multiple clients to acquire
the stream at the same time by requesting a copy from the multicast group address. Therefore,
enabling multicast can effectively save Internet bandwith.
The ports can be changed to values between 1025 and 65535. The multicast RTP port must be an
even number and the multicast RTCP port number is the multicast RTP port number plus one, and
thus is always odd. When the multicast RTP port changes, the multicast RTCP port will change
accordingly.
If the multicast RTP video ports are incorrectly assigned, the following warning message will be
displayed:
Multicast TTL [1~255]: The multicast TTL (Time To Live) is the value that tells the router the range
a packet can be forwarded.