Hey guys

I've got a problem that seems to be caused by the introduction of a RB250GS into my home network.

What works: Fiber to the home, ONT to Actiontec router, IPTV STB plugged directly into the router
What doesn't: RB250GS in between the Actiontec router and the IPTV STB

The IPTV uses the Microsoft Mediaroom platform and my understanding is that it uses unicast when changing channels (a burst of fast buffer filling) then multicast for regular reception once everything's caught up.

It worked fine at first - no problems watching or recording anything. I installed the RB250GS (running 1.6) in between the wall outlet and the STB, then also plugged in my Xbox. This seemed fine for about a week, then things started getting glitchy. Sometimes watching TV would freeze, stutter, go all pixelated etc.. The same applied to recording TV - programs would be all glitchy to begin with and sometimes you could fast forward a few minutes in and it would settle down and be watchable, other times it would be a bad recording all the way through.

I'm confused because this setup worked fine for a while it seems, then started acting up. My gut reaction is always to ask "what changed?" but in this case I think the only thing that changed was the IP address of the RB250GS and the description on the SNMP page. I've power cycled it a bunch of times and got to the stage where I could reproduce the problem when it was connected, and was problem free when it wasn't. Frustrating!

I've got a few more RB250GS's kicking around, so I'm going to switch the unit out for another one and see how it behaves.

Does anyone have any ideas on anything that could be config-related and causing this problem though?

Thanks in advance
Paul

As an update.. I swapped the RB250GS for another one, same deal. Swapped it out for a cheap and nasty Dynex 10/100 switch and same deal.. so it's less about the RB250GS specifically..

Watch a HD stream, all good. Set another stream to record - it goes glitchy.

A friend suggested it was the frequency of the packets, but I'd have expected the RB250GS to be able to cope, no? It's a gigabit switch and the IPTV is only a 100Mbps device.. so.. I'm stumped - anyone got any ideas?

Another Update: If I use the ACL to redirect everything from Port 1 (plugged into the Actiontec) to Port 2 (plugged into the STB), everything works fine. I can watch an HD stream and record 2 others with no glitching or problems.

I'm wondering then if the issue is broadcasting the multicast traffic out to each port (and me not needing it to go to ports 3 through 5).

With an ACL rule to match the IPTV traffic, I should be able to enforce the "redirect to port 2" functionality, but only for the IPTV stuff, right? I had a quick play yesterday, using priority and DSCP fields, but couldn't get it to work as expected. The wiki page/documentation is a bit sparse on this - are the values meant to be decimal or hex? Any specific format?

I'm wondering then if the issue is broadcasting the multicast traffic out to each port (and me not needing it to go to ports 3 through 5).

RB250GS doesn't support IGMP Snooping - it means that multicasting is handled like broadcasting. I think your IPTV has it's own IP address, so you can make ACL that redirects it only to desired ports - use IP of IPTV as "Ip Dst". See discussion: http://forum.mikrotik.com/viewtopic.php?f=17&t=54590

Hey Zervan

Yes, I saw that post and it totally sorted my problem out!

I have an ACL rule for 224.0.0.0/4 to be redirected only to the port the IPTV STB is connected to and it works great - multiple streams recording, no glitches, and just 2 blinking lights not 5.

Thanks!
Paul

Hey Pau / everyone else,

I know this is a really old post, hope it is ok to revive this. Trying to figure out if getting this to work would be easier to do with the latest version of RouterOS.

So I just bought a new 750GL. Running RouterOS 6.29.1 and I have the multicast package installed. On my network I have two Telus STBs and they are not plugged into dedicated ports in the 750... for all means and purposes, one is on port 2 (through a switch which serves multiple other devices) and the 2nd one is on port 3, plugged in directly.

I'm currently stuck on the the spot where the channel freezes about 10 seconds after switching to it... Just trying to get one working (port 3) and I will then attempt the second one. Ultimately, I would like to get this working through any port the STBs are plugged into (like how the Actiontec accepts it, even over wifi)

This is my configuration currently:



Which seems to be doing... something.... but I still have the same error:



aaaand... now I'm stuck. Sorry but this is how far my networking skills go Can anyone shed some light on the subject for me?

Thank you very much in advance.