Troubleshoot home network congestion

I have a home network consisting of 1 wireless router connected to the internet, and then a number of clients directly connected to it on both ethernet and wireless, as illustrated below:

All clients are on the same /24 net (192.168.1.0-255). On each device internet connectivity is working very well.

When I start streaming a movie from Netflix on PS3_1 (regular PS3), or even if I stream video locally, from NAS_1 (Synology DS207+), gaming between the LAPTOP's and the DESKTOP computers start lagging a lot (so bad you can't even enjoy a LAN game of WC3 or CS). Online gaming starts lagging too (only noticed it with Diablo 3 though).

How can I troubleshoot this? Can I inspect some traffic on the router maybe?

The WIFI router is a Zyxel P-2812HNU-F1

Mathias R. Jessen

Posted 2013-02-11T20:33:52.150

Reputation: 352

whats your wired network spec? Gigabit? how good a switch do you have? – Frank Thomas – 2013-02-11T20:36:53.770

NAS_1, DESKTOP_1 and TV_1 are all plugged directly into the back of the router with standard RJ-45/Cat 5 cables – Mathias R. Jessen – 2013-02-11T20:39:29.747

I'd certainly recommend putting a switch in line, perhaps moving the Wireless to a WAP, rather than using the ISPs device. your network is a little too big for a single device to keep up with it all, and any congestion will be felt by all nodes the way its set up now. – Frank Thomas – 2013-02-11T20:47:17.927

Thanks for the recommendation - any good reads/links for setting up home networks? – Mathias R. Jessen – 2013-02-11T20:54:10.470

Answers

The congestion is occurring because of your WIFI link. You may want to try a different WIFI channel, moving the devices closer or enabling/getting hardware that is capable of handling 2 channels simultaneously and/or working on another band (ie 5 gig) band. Moving as many devices onto the wired connection as you can will also help. (Also, if your WIFI router is not 802.11n, upgrade to 802.11n, and get a router with multiple antennas so it can do MIMO). [ You might also be able to get a small boost by disabling older protocols like 802.11b if all your gear is g capable, or disabling 802.11b and g if all your gear is 802.11n capable]

One way of troubleshooting would be to use ping/mtr and monitor your performance as you do various things (and at various times of the day). Also, using a wifi analyser of some sort to see the noise on channels etc.

davidgo

Posted 2013-02-11T20:33:52.150

Reputation: 49 152

Thanks, I have another AP in spare that I'll try to move all wifi devices to instead. inSSIDer also revealed some interesting stats on the distribution of wifi channels in use in the area, I'll choose a band that is not used. Will report back! – Mathias R. Jessen – 2013-02-12T11:03:53.417

My RT-N66U can push 200Mbit across WiFi, which is much more bandwidth than any service would require. Good enough.

To stream-line trouble-shooting by removing unknowns, use iperf to benchmark your WiFi network's capabilities. Test from a wireless iperf session to a wired iperf session because if you were to test with both iperf sessions on wireless, it would halve your thoughput results because WiFi is a shared resource.

Ben Cook

Posted 2013-02-11T20:33:52.150

Reputation: 166

Having a look at the traffic is easy if you can install OpenWRT (or similar) on the router. There are even devices which become twice as fast after the change to OpenWRT. So if that is at least a theoretical option for you have a look at the compatibility list on www.openwrt.org. Or consider getting a new one.

Hauke Laging

Posted 2013-02-11T20:33:52.150

Reputation: 275