Axis Communications AXIS 233D - Manual (Page 15)

15 AXIS 233D - Video Streams
How to stream MPEG-4
Deciding on the combination of protocols and methods to use depends on your viewing
requirements, and on the properties of your network.
RTP+RTSP
This method (actually RTP over UDP and RTSP over TCP) should be your first consideration
for live video, especially when it is important to always have an up-to-date video stream,
even if some images do get dropped. This can be configured as multicast or unicast.
Multicasting provides the most efficient usage of bandwidth, especially when there are
large numbers of clients viewing simultaneously. Note however, that a multicast broadcast
cannot pass a network router unless the router is configured to allow this. It is thus not
possible to multicast over e.g. the Internet.
Unicasting should be used for video-on-demand broadcasting. However, if more and more
unicast clients connect simultaneously, the server will at some point become overloaded.
There is also a maximum of 20 simultaneous viewers to be considered.
RTP/RTSP
This unicast method is RTP tunneled over RTSP. This can be used to exploit the fact that it
is relatively simple to configure firewalls to allow RTSP traffic.
RTP/RTSP/HTTP or RTP/RTSP/HTTPS
These two methods can also be used to traverse firewalls. Firewalls are commonly
configured to allow the HTTP protocol, thus allowing RTP to be tunneled.