NewTek TriCaster 850 User Manual page 265

A variation on the Pull method involves using an external streaming provider. At one time the
only method for streaming using such a provider was to have the server 'pull' it from the
encoder.
Under this system the server did not receive the stream until the first user requested it. Then the
server would connect to the encoder, pull the stream to it, and finally begin re-distributing it to
everyone requesting it. This method worked passably until firewalls became more common.
 Advantages:
o
Pull doesn't waste bandwidth; no signal is being sent out to the server unless
somebody wants to view it.
o
If you lose your connection to the (provider side) server, the server will re-
connect to your encoder automatically when Internet connection resumes.
o
Providers typically have significant bandwidth, and are able to meet necessary
requirements to deliver stutter-free, high quality streams to large numbers of
viewers.
 Disadvantages:
o
Like the "Pull by End Users" method above, this requires a public IP address,
preferably a "static IP address" (which does not change dynamically if you need
to reconnect) as well as open ports for the connection to be established. These
requirements are becoming increasingly difficult to meet (given common
security measures).
PUSH TO PROVIDER
Windows 2003 Server introduced "Push" technology. With this method, the encoder sends the
stream to downstream servers. This allows the encoder to establish a connection to the server
on a specified port. Once this connection is established, additional network ports may be
opened as required (since the Encoder established the connection, not the server.)
 Advantages:
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