Vivotek SD8333-E User Manual page 71

Multicast settings for stream 1, 2, 3, and 4: Click the items to display the detailed configuration
information. Select the Always multicast option to enable multicast for video streams.
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.
Initial TTL
0
1
32
64
128
255
Scope
Restricted to the same host
Restricted to the same subnetwork
Restricted to the same site
Restricted to the same region
Restricted to the same continent
Unrestricted in scope
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User's Manual - 71