Using OmniStream
™
with Velocity
™
Device Manager
9
Introduction to OmniStream
Subscribing to a Stream
To receive information from an encoder, the decoder must
subscribe
to the multicast IP address and UDP port of
the stream(s). Note that the decoder does not subscribe to the session, but to the stream(s) within the session.
The process of subscribing is similar to changing the channel on a Set-Top Box. For example, in order to view the
content on channel 213, the Set-Top Box must be set to channel 213. Similarly, for a decoder to subscribe to an
encoder stream,
the multicast IP address and UDP port settings on the decoder must be set to the same values as
the encoder to which it is subscribed.
Note that the management IP address of a unit is different than its multicast IP
address.
Figure 1.4
shows two encoders and a single decoder connected to a network switch. Decoder “C” is subscribed to
encoder “A”, since the multicast IP addresses and UDP port numbers for both video and audio are set to the same
values as encoder “A”.
Figure 1.3 - Diagram of a video and audio stream, transmitted over an Ethernet cable, to the subscribing decoder.
Video Data
Audio Stream
Video Stream
Multicast IP: 226.0.0.1
Multicast IP: 226.0.10.1
UDP Port: 1000
UDP Port: 1100
Ethernet
Encoder
Video
Destination Multicast/Unicast Address
226.0.0.1
Destination UDP Port
1000
Audio
Destination Multicast/Unicast Address
226.0.10.1
Destination UDP Port
1100
Decoder
Video
Subscribed Multicast Address
226.0.0.1
Port
1000
Audio
Subscribed Multicast Address
226.0.10.1
Port
1100
AT-OMNI-111
AT-OMNI-121
PoE Network Switch
Ethernet
Stream
Ethernet
HD
MI
PW
R
LINK
TM
O
MNI
S
TREAM
AT-OMNI-111
HD
MI
PW
R
LINK
TM
O
MNI
S
TREAM
TM
O
MNI
S
TREAM
LINK
PW
R
Stream
Ethernet
A
B
C
Encoder IP Address:
192.168.1.27
Multicast IP Address (Video):
226.0.0.1
UDP Port (Video):
1000
Multicast IP Address (Audio):
226.0.10.1
UDP Port (Audio):
1100
Decoder IP Address:
192.168.1.38
Multicast IP Address (Video):
226.0.0.1
UDP Port (Video):
1000
Multicast IP Address (Audio):
226.0.10.1
UDP Port (Audio):
1100
Encoder IP Address:
192.168.1.98
Multicast IP Address (Video):
226.0.0.2
UDP Port (Video):
1000
Multicast IP Address (Audio):
226.0.10.2
UDP Port (Audio):
1100
Figure 1.4 - Decoder “C” subscribed to encoder “A”.