Using a switch between Actiontec and STB causes problems? - Canadian TV, Computing and Home Theatre Forums

paulcrick · 2012-05-19, 10:40 PM

I recently signed up for Telus Optik and have been pretty happy so far. I've got fibre to the home and the tech did a great job connecting it all up. I had 3 STBs connected via ethernet back to the Actiontec, and a port for my PC too.

Now I want to connect an Xbox and/or Apple TV in the mix, and here's where the problem begins...

I'm thinking "This is just data right? IP networking? so I'll take the cable that's going from the wall to the STB and plug it into a switch, connect the STB to the switch, and the Xbox, and we should be all good!" Except... we're not :-(

I've tried with a MikroTik RB250GS (a semi-managed 5 port gigabit switch) as well as a cheap'n'nasty Dynex 10/100Mpbs 8 port switch, and have identical results.

STB direct to wall = no problem.
STB via switch = freezing, glitching, pixelization as soon as more than one stream is in use. I can watch one HD stream and it's fine, but if I go to the guide and start recording another, problems ensue.

I'm thinking the easiest solution might be to just stick the STBs on coax, as I have outlets pretty much in the same place as the existing ethernet jacks.. If I do this, I'm guessing it's connect each STB to the coax, then in the basement connect the coax output on the Actiontec to the splitter that's currently feeding the coax outlets throughout the house? Maybe a router reboot and we're good? But the techie in me wants to understand why it doesn't work as expected, with an ethernet switch. Is there anything that can be done with settings/configuration? Is it a multicast thing? A friend suggested it's a "high frequency of packets" for the TV streams and the switches can't cope - I could see this for the crappy 10/100 switch, but the specs for the RB250GS say it can do 411,500 frames per second (1518 byte frames) which seems like more than enough for the TV streams, no?

Any ideas/advice/thoughts on the whole thing gratefully received...

ac · 2012-05-19, 11:46 PM

Is it possible you have a bad patch cable in the mix? I have 2 trendnet gigabit switches in between my Actiontech and the STB both switches have Xbox's, one has a PS3 and a Wii and I don't have any issues.

If you have a laptop handy you might want to plug into the switches and run some speedtests to see if there is something else going on. (At the very least see if you are losing any packets on a ping test).

You might also want to set the gigabit switch to 100mb/s and see if things improve, I know it sounds counterintuitive, but I have seen similar type issues with other applications.

paulcrick · 2012-05-20, 01:45 PM

Thanks - I'll give that a whirl this afternoon. Are your Trendnet switches managed or configured in any way? or just dumb switches?

With the MikroTik RB250GS there are some ACL settings you can change. Setting it so that the two switch ports are private to each other (to wall, and to STB), it works a treat.. and I can set a similar forward rule based on protocol, priority, DSCP and a few other things, so if I can figure out what the multicast traffic looks like, this may solve the problem.

I sense a laptop + Wireshark session coming on :-)

Dr.Dave · 2012-05-21, 12:52 AM

paulcrick, all the video data is UDP. When you first tune to a new channel, the data is sent as unicast for a few seconds and then switches to multicast.

paulcrick · 2012-05-22, 04:49 PM

As an update: Using the ACL functionality on the RB250GS, I'm able 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. I had a quick play yesterday, using priority and DSCP fields, but couldn't get it to work as expected. The wiki page/documentation for the RB250GS is a bit sparse on this - I'm not sure if the values meant to be decimal or hex. I'll do some more Wireshark sniffing and see if I can figure it out.

mrkeeeler · 2012-07-27, 02:39 PM

I had the same issues.

Mine worked fine for the first 6-8 months of having optik than i started to have this problem. My xbox, ps3, and computer that were connected to the switch (dlink giga) all worked fine.

Just had an issue of my modem crapping out and when they replaced it the guy ran a new dedicated line for the STB and bam no more problem.

rewrite · 2012-08-04, 05:16 AM

if your managed switch has IGMP snooping feature, turn it on and it will direct multicast traffic only to the ports that need them. I have a netgear prosafe plus 8 port switch that supports it and with IGMP snooping turned on, it forwards only tv traffic to the port STB is connected to and not flooding any other ports like my other cheap switches would do.

i6s1 · 2012-08-24, 11:33 AM

A weird problem we've seen a few times is pixelization on the STB when the computer (connected to the same switch) is on standby. Don't know what causes it but turning the computer off or hibernate solves the problem. Or running a dedicated line.

2012-05-19, 10:40 PM	#1
paulcrick Rookie Join Date: Jan 2012 Posts: 4	Using a switch between Actiontec and STB causes problems? I recently signed up for Telus Optik and have been pretty happy so far. I've got fibre to the home and the tech did a great job connecting it all up. I had 3 STBs connected via ethernet back to the Actiontec, and a port for my PC too. Now I want to connect an Xbox and/or Apple TV in the mix, and here's where the problem begins... I'm thinking "This is just data right? IP networking? so I'll take the cable that's going from the wall to the STB and plug it into a switch, connect the STB to the switch, and the Xbox, and we should be all good!" Except... we're not :-( I've tried with a MikroTik RB250GS (a semi-managed 5 port gigabit switch) as well as a cheap'n'nasty Dynex 10/100Mpbs 8 port switch, and have identical results. STB direct to wall = no problem. STB via switch = freezing, glitching, pixelization as soon as more than one stream is in use. I can watch one HD stream and it's fine, but if I go to the guide and start recording another, problems ensue. I'm thinking the easiest solution might be to just stick the STBs on coax, as I have outlets pretty much in the same place as the existing ethernet jacks.. If I do this, I'm guessing it's connect each STB to the coax, then in the basement connect the coax output on the Actiontec to the splitter that's currently feeding the coax outlets throughout the house? Maybe a router reboot and we're good? But the techie in me wants to understand why it doesn't work as expected, with an ethernet switch. Is there anything that can be done with settings/configuration? Is it a multicast thing? A friend suggested it's a "high frequency of packets" for the TV streams and the switches can't cope - I could see this for the crappy 10/100 switch, but the specs for the RB250GS say it can do 411,500 frames per second (1518 byte frames) which seems like more than enough for the TV streams, no? Any ideas/advice/thoughts on the whole thing gratefully received...

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

2012-05-19, 11:46 PM	#2
ac Join Date: Mar 2003 Location: Vancouver Posts: 179	Is it possible you have a bad patch cable in the mix? I have 2 trendnet gigabit switches in between my Actiontech and the STB both switches have Xbox's, one has a PS3 and a Wii and I don't have any issues. If you have a laptop handy you might want to plug into the switches and run some speedtests to see if there is something else going on. (At the very least see if you are losing any packets on a ping test). You might also want to set the gigabit switch to 100mb/s and see if things improve, I know it sounds counterintuitive, but I have seen similar type issues with other applications.

2012-05-20, 01:45 PM	#3
paulcrick Rookie Join Date: Jan 2012 Posts: 4	Thanks - I'll give that a whirl this afternoon. Are your Trendnet switches managed or configured in any way? or just dumb switches? With the MikroTik RB250GS there are some ACL settings you can change. Setting it so that the two switch ports are private to each other (to wall, and to STB), it works a treat.. and I can set a similar forward rule based on protocol, priority, DSCP and a few other things, so if I can figure out what the multicast traffic looks like, this may solve the problem. I sense a laptop + Wireshark session coming on :-)

2012-05-21, 12:52 AM	#4
Dr.Dave Moderator Join Date: Aug 2005 Location: Winnipeg Posts: 4,821	paulcrick, all the video data is UDP. When you first tune to a new channel, the data is sent as unicast for a few seconds and then switches to multicast.

2012-05-22, 04:49 PM	#5
paulcrick Rookie Join Date: Jan 2012 Posts: 4	As an update: Using the ACL functionality on the RB250GS, I'm able 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. I had a quick play yesterday, using priority and DSCP fields, but couldn't get it to work as expected. The wiki page/documentation for the RB250GS is a bit sparse on this - I'm not sure if the values meant to be decimal or hex. I'll do some more Wireshark sniffing and see if I can figure it out.

2012-07-27, 02:39 PM	#6
mrkeeeler Rookie Join Date: Jul 2012 Posts: 1	I had the same issues. Mine worked fine for the first 6-8 months of having optik than i started to have this problem. My xbox, ps3, and computer that were connected to the switch (dlink giga) all worked fine. Just had an issue of my modem crapping out and when they replaced it the guy ran a new dedicated line for the STB and bam no more problem.

2012-08-04, 05:16 AM	#7
rewrite Join Date: Jan 2011 Posts: 31	if your managed switch has IGMP snooping feature, turn it on and it will direct multicast traffic only to the ports that need them. I have a netgear prosafe plus 8 port switch that supports it and with IGMP snooping turned on, it forwards only tv traffic to the port STB is connected to and not flooding any other ports like my other cheap switches would do.

2012-08-24, 11:33 AM	#8
i6s1 Join Date: Jan 2010 Location: TELUS Employee Posts: 189	A weird problem we've seen a few times is pixelization on the STB when the computer (connected to the same switch) is on standby. Don't know what causes it but turning the computer off or hibernate solves the problem. Or running a dedicated line.