DynaDish EtherMPX Multicast stream

RouterOS Wireless Networking
1

Hi all,

For my volunteering job I’m currently building an wireless bridge using the DynaDish 5. We use EtherMPX encoder and decoders for transferring a MPX-signal from our main studio to a sender location. The multicast stream is working across the DynaDish link, but the quality is very bad. It might be caused by misconfiguration in RouterOS.

According to our supplier it’s possible to have such a link across the Ubiquity Nanobeam, so in my opinion it should be possible to have such a link across the DynaDish as well.

Has anyone ever build such a link before and what configuration settings I might have to be looking for?

2

Hi Bram,

is that stream using multicast?, fix could be : use higher basic rates, or use multicast helper :slight_smile:

Vriendelijke groet,

Menno

3

Oops due to the time i missed it : its multicast! What rate so you need? What protocol are you using? Whats the TX and RX levels at both ends?

4

Its indeed a multicast stream. Last night we got a pretty decent signal with just a little bit of jittering. When we initial started setting things up we where looking at the PIM en IGMP-proxy setting. But I realised we where looking at the wrong place, since multicast traffic was already arriving at the other site.

I’ve tweaked around with lots of wireless settings. I’ve got good results with both nv2 en nstreme protocols. Nstreme seems to be the best solution for this with Ping-times less than 1 ms. But we’re still experiencing some jitter in the signal due to higher ping times (between 2 and 7 ms). We’re currently looking to bring that down.

I’ve tried several settings, including setting tdma to the lowest delay in nv2 modus (1ms) and tweaking around with Channel Width. Multicast helper is enabled on both ends (following on a suggestion in another topic on this forum), but only enabling multicast helper didn’t work for me. What possible setting could I be looking at more?

5

Since we’ve figured it all out and this link is currently running providing data to our remote broadcast station without any issues. We’ve tweaked around with lots of settings on the Wireless cards of both devices and got a good link with stable ping response times.

This topic may be closed.

6

For future reference, it would be nice of you to write down here settings that you have tweaked so other members could find it in the future.
Thanks

7

Of course, I don’t have currently access to all values of the changed settings. And I don’t know if my settings are the best possible settings to achieve te optimal result, it is probably a trail and error process. Since our current installation is live and all changes made impact our broadcasting I can’t do more configuration. We’re looking to expanding this process for more Point-to-Point links, if we build that we’ve got more time to make a good documentation.

Settings I’ve changed (may) included:

  • Enabling multicast-helper on both ends of the link
  • Changing both MTU and L2 MTU size
  • Setting a static frequency
  • Disabling CSMA
  • Setting framer-policy to exact-size
  • Setting framer-limit to max (4000)
  • Setting tmda-period-size to 1
  • Changing channel width to 20Mhz only
  • Unchecking all checked at ampdu-priorities

It’s possible I’ve forgotten to mention some settings I’ve changed. I’ll update this topic if I remember it or when I’ve had a better change to do more trail-and-error testing on our new link