User guide

40 Chapter 5
Streaming Server
Version 3.1
Using 4Sight as a reflector
Most routers on the Internet cannot properly interpret multicast
information as they are set up to transfer traditional Internet Protocol (IP)
unicast packets that have a single, specific destination.
A reflector is an RTSP server that has the ability to join a multicast, and to
convert the multicast stream into a series of individual unicast streams. A
reflector feeds each client with an individual stream.
In most cases, the reflector receives a stream from a broadcaster (an
application which sends RTP packets) such as Envivio 4Caster. The
reflector forwards the RTP streams on request, in real time. The SDP file
generated by the broadcaster must be placed in one of the movie folders of
4Sight.
If you want the EnvivioTV
TM
client to connect to the reflected broadcast,
use the following URL:
e-rtsp://name_of_the_server:7070/live.m4e
where live.m4e is the name of the SDP created by the Playlist Broadcaster
(or any other broadcaster).
WARNING If you use reliable UDP (see “reliable_udp” on page 113), check that the
M4E file does not contain the following line:
b=RR:0
This may prevent the player from sending the RTCP packets that are
mandatory for using reliable UDP.
NOTE There is no fixed limit to the number of live broadcasts that a server can
reflect, nor to the number of clients that can connect to one reflected
broadcast. The only limitations are the CPU, the memory and the
bandwidth.