Have you ever faced the situation that you want to use Multicast between subnets, but Routers don’t forward it OR the application/device generating the Multicast traffic is using a TTL of 1, so the blocks don’t get forwarded by the router?

Barix developed a “Multicast routing/tunneling” firmware for the Barionet which turns that device into a flexible, multi site multicast forwarder/router. Effectively, it bridges multiple multicast groups between multiple sites, and can also include single hosts. The functionality is independent on the actual protocols used with the Multicast, being it automation, IP Audio, Video, VoIP, SIP or RTP.

Here is the rough concept:

• A Barionet is installed in every subnet where multicast traffic needs to be pickeed up or delivered.
• The device(s) does “UDP” tunnelling to forward the Multicast packets to the other Barionet(s) in the other subnet(s). At the same time, they serve as a tunnel receiver/endpoint to receive encapsulated Multicasts from the other networks.
• Up to 8 independent multicasts (address/port) can be configured, and up to 8 destinations – either Barionets in other networks as tunnel endpoints, or hosts which then receive the packets unicast.
• The TTL field of the multicast blocks can be “ignored and set to configured value” or handled as usual (decrementing).
• Tunnelling can be configured to use “IP over IP” or plain UDP – both have advantages and disadvantages.
• Monitoring of the application is possible via SNMP.

The first customer uses the application to route VoIP/VHF radio traffic between multiple operations centers in a large company. However, applications can be found wherever multicast needs to be routed between subnets and routers, IT providers or policies prevent that.

Please contact Barix if you are interested in that solution!

Johannes