Multicasting across Wireless

Hi all,

since a few have been asking about multicasting over wireless links with Mikrotik, I thought I’d share my little success.

A client wants to send out 5 streams of video to several multiple sites. We got this to work by setting up a WDS bridge (set both interfaces to Bridge, set up WDS link). Once that was done, a single copy of the multicast stream is always sent out over the link, no difference if there are 0 or 100 clients.

I think the bandwidth available to multicast traffic will be limited to the basic data rate (6Mbps on 802.11a), which wasn’t more than enough for this setup, but I guess if we fix the basic data rate to a higher value, the higher bandwidth will also be available to multicast traffic.

Hi Andrea,

We’re very interested in that-

What are you using : IGMP multicast?

Best regards

Stephen

Just a regular Windows 2003 Enterprise box with Windows Media Encoder, default settings, streaming 3x low bandwidth (approx 300k) pre-recorded streams, 1x medium bandwidth (approx 900k) pre-recorded stream, and 2 medium-bandwidth live streams.

You must test the multicast transfer rate whit Iperf.

Server: iperf -s -u -B 224.0.55.55 -i 1
Clients: iperf -c 224.0.55.55 -u -T 32 -t 10 -i 1

The results obtained with MT are much disappointing, max 3-4Mbps and 4-10% Paket loss !!!
Alvarion for example, it obtains 9-10Mbps and 1% paket loss.
Windows media streaming it is not a valid system of test !

Bye Cuccio