Subnet questions??? - network guru's please read.

[PGPfan]

Hi Guys,

I have a network running at home with 2 machines that play A LOT of World of Warcraft. Problem is that when I try to watch a movie from my server (Linux powered) streamed through my HTPC to my MVP's with Sage I see some occaisional glitching/stuttering and the WoW machines seem slower.

Would a subnet dedicated to ONLY Sage and my server help in this situation?

My network is like this:

Internet connection is provided via Wildblue satellite internet.

Netgear WGR614 V.7 router feeding D-Link Gigabit switch (call it switch 1). My HTPC, server, and one XP Pro machine connect at this D-Link switch (switch 1). A second D-Link Gigabit switch (call it switch 2) is connected to switch 1 and feeds the MVP's, and the 2 machines that run WOW (all located on a different floor).

I also have a Linksys BEFSR41 that isn't currently being used. I could possible use this router to make a subnet off of the Netgear, right? If so, how might I create this subnet?

Anyone have any ideas on how I might solve my problems?

Thanks in advance for any help!

-PGPfan

[stevech]

My suggestion...
Stay with one subnet
On the Netgear wireless router - use only one connection between it and your gigabit switches.
Keep all PCs in the same subnet. All the packets (should) avoid passing through your (crummy - I used to have one) Netgear wireless router. These $50 routers sometimes don't have a real switch in them.
Assure that all your traffic goes through your switches only, not through the routers.
The gigabit switches are nice, but of course, the MVPs and PCs are likely not gigabit.

I would speculate that your glitching comes from data starvation at the file server, esp. if it's Linux-based and/or RAID5, and not setup with big 64KByte disk allocation clusters. Some of the stand-alone RAID servers use file systems that aren't appropriate for big video streaming problems.

------------
"unRAID Server uses the ReiserFS journalled file system."

[PGPfan]

I should have been a little more specific. All the PC's have GigE nics (all are Nforce 4 boards). There is only one connection currently going IN to the router from the Wildblue modem, and one connection going OUT to the D-Link switch (switch 1).

As for starvation from server, I don't think that is it since I can watch multiple streams just fine from the server directly on the HTPC (using TheaterTek, for example) and my main PC. No hiccups at all and they both have the D-Link (switch 1) between them.

-PGPfan

[hemicuda]

I'm seeing "glitches" on my MVP similar to dropped frames; intermittently. Happens on both "Live" and pre-recorded shows. Seems not to care what the Sage server is doing or how it's loaded.

Everything runs through a Linksys 16 port switch: MVP, wireless AP for wife's TiVo, server, n*x router.

[stevech]

Is this specific to a vintage of MVP?
Does it happen only when the scenes are "busy", e.g., camera is panning a scene with a lot of detail?

[PGPfan]

Doesn't seem 'vintage' specific. I have a newer MVP (less than 5 months) and an older (about 2.5 years old) one and both exhibit the same behavior.

As for specific scenes, I wish I could nail it down like that. It REALLY seems to be random, which is why I'm suspecting network traffic due to the WoW machines but I don't know for sure.

Do you know of an easy way to look at network traffic?

-PGPfan

[ke6guj]

Before I went to the effort of setting up a second subnet, I'd try to rewire your existing network. Set up all the Sage stuff, server and MVP's onto 1 switch, and have the rest of the stuff onto a second switch. IF what you are seeing is a network problem, it may be possible that you are overloading the switch.

If you can, have each switch plug directly into the router. That way, you don't have any WOW traffic going through the Sage switch, or vice-versa. As long as you don't have anything "broadcast storming" the network, segregating the network behind separate switchs should totally elimate Sage and WOW from affecting each other. IF you still want to set up a second subnet after all, you could just swap out the Sage switch with the second router.

You could set up the second subnet a couple different ways. Decide on a second IP range for the new LAN that isn't the same as the first. Port forwarding can be an issue, so you need to know what the WAN IP address is for the second router. For the WAN port, set it up either with a static IP address from the first LAN, or use DHCP if need be. If using DHCP, you need to assign the second router's WAN port MAC address to always be assigned a "static" IP address in the the DHCP server.

Once you have the second router statically set, then you can forward all the Sage ports on the first router to the second routers WAN IP address. Then in the second router, you can then forward the Sage ports to the Sage server.

As you can see, it can be a pain to configure. A second subnet would be the last thing to try.

[GKusnick]

Originally Posted by PGPfan

Do you know of an easy way to look at network traffic?

Windows XP TaskManager has a basic network utilization monitor.

For measuring network throughput, I use Ixia Qcheck. You could try doing some throughput measurements from, say, your file server to your Sage server, and from your Sage server to your Sage clients, with and without WoW running, to see if there's a measureable difference. You also might use this to identify bad sections of cabling that are dragging down network throughput.

If you have more than one Cat5 running between floors (or can easily pull a second one) then it would definitely be worth an experiment to put the WoW machines on a separate switch feeding directly into the router, so that their traffic doesn't mingle with the Sage traffic on the same floor-to-floor cable.

[PGPfan]

Thanks guys, I'll work on segregating the switches tomorrow and report back.

-PGPfan

[dagar]

Are you running Jumbo frames on your GbE devices?

[PGPfan]

Nope, no jumbo frames. I'm not sure, but I don't think the Nforce 4 nic supports jumbo frames.

-PGPfan

[ben_95sl1]

There's a way to enable jumbo frames on nforce 4 boards apparently; I read a long set of posts describing how to do that on avs forum, the home theater pc section (it was about tweaking gigabit connections). I would be doing it as well, but I have non jumbo frame 100mbit nic on the network as well, so probably won't even work for me.

[MrApollinax]

Originally Posted by PGPfan

Hi Guys,

I have a network running at home with 2 machines that play A LOT of World of Warcraft. Problem is that when I try to watch a movie from my server (Linux powered) streamed through my HTPC to my MVP's with Sage I see some occaisional glitching/stuttering and the WoW machines seem slower.

Would a subnet dedicated to ONLY Sage and my server help in this situation?

I've been thinking about this one and I really don't think that this would help you in your situation. As far as I know WoW when hooked into the server for a session is sending traffic out to servers on specific ports. Your WoW machines should not be broadcasting on your LAN, they should be unicasting towards the default gateway since that is where they need to send packets to get to the Blizzard servers. I would think that the same would go for your SageTV setup.

I agree with what others are saying. Daisy chaining your switches in this case is probably what is causing your issues. I have the same switches you do but you got to keep in mind when you are using 'dumb' switches in this manner you increase the chances of collisions happening between the two switches. If you have less than stellar wiring between the two switches you will only compound the problem as you pull more data through the switches. This is something I learned about the Dlink GigE switches I have here.

[ramble=nerd]
If you really wanted to create prioritization on your lan i would go with a central managed switch. I would then give the sage switchports a higher priority over the WoW machines. [/ramble]

[AngelofDeth]

Originally Posted by MrApollinax

Daisy chaining your switches in this case is probably what is causing your issues. I have the same switches you do but you got to keep in mind when you are using 'dumb' switches in this manner you increase the chances of collisions happening between the two switches. If you have less than stellar wiring between the two switches you will only compound the problem as you pull more data through the switches. This is something I learned about the Dlink GigE switches I have here.

I have my Sage system daisy chained... four switches involved including the one the MVP plugs into. I do get occasional "blips", but its not really enough to concern myself with trying to fix it. The OP doesnt really say how bad these "blips" are, but in my case my MVP is probably 200 feet or more from the sage server, it works well considering.

[MrApollinax]

In my experience with switchports not designed with trunking in mind you run into a higher chance of collisions. In this case you have a giant collision domain. Without using VLANs to seperate the traffic into smaller collision domains you run the risk of having more collisions. When you are doing very little traffic on the other clients you may not see this issue. But a client on the very last switch pulling down a lot of data may cause some network troubles on the very first switch when combined with the traffic being pulled down on the 2nd and 3rd switches.