Quick Start Guide
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Inter-site stream transfers using a corporate VPN
When there is a ‘quality
-
controlled’ VPN joining different corporate sites, it is possible to use Re
-Casters
to transfer live IP TV multicast streams across the VPN.
A VPN link is rarely capable of transferring a multicast IPTV stream directly across it and so the Re-Caster
on the source side (Site A) collects the multicast stream from the LAN and transfers it across the VPN as
a unicast stream directed at the Re-Caster on the destination side (Sites B and C). The destination Re-
Caster then re-launches the stream onto the local LAN as a multicast stream again. Settops and PC/MAC
viewer software on the remote (destination) site can then access the multicast stream for viewing in the
usual way.
A ‘quality
-
controlled’ VPN is one where it can be assumed th
at the QoS is the same as for multicast
streams passing across a LAN. This means little or no IP packet re-ordering or packet loss. If you set up
your system as described below, and you are seeing TV picture breakup on the destination LAN, then it is
likely the quality of your VPN connection is not good enough. In this case you can set up the Re-Casters
to use an
SRT connection over the VPN which will then correct the packet losses. The ‘cost’ of this is an
additional second of stream transfer latency and the ability to transfer fewer IP TV streams per Re-Caster
pair.
To set up a VPN link from site A to sites B and C, configure the Re-Caster routing table on
Site A
as
follows:
1.
Click on the
Routing
web page link on the left-hand side panel.
2.
Check the Enable Source checkbox. Select the UDP:// setting from the Source field drop-down
and enter the local multicast address of the IP TV channel you wish to distribute. If you wish to
distribute a unicast IP stream being sent directly to the Re-Caster, enter its receiving port number
only.
3.
Click on the list box symbol at the right-hand end of the Source field. Enter the IP address (or
host name) of the Encoder or LAN-Caster
device
that is producing the IP stream (
not the stream
address!
). The Re-Caster will check all the stream data being transferred comes from that
device. Any stream data that comes from another IP address will not be forwarded.
4.
Check the Enable Destination checkbox. Select the UDP:// setting on the Destination field drop-
down and enter the IP address (or host name) and port number of the receiving Re-Caster device
on Site B.
If the Re-Caster needs to stream the same IP TV channel source to another multicast or unicast
address or other SRT linked site, click on the Enable checkbox on the Destination field below and
add more destination addresses.
