Router causes lag

Post by **obsidian** » Thu Sep 28, 2006 4:37 pm

I noticed periodic lag when gaming, so I decided to investigate. It seems like my router is doing some weirdness every minute or so that is causing the lag.

I have a Linksys WRT54GL wireless router, and I have a WMP54G desktop card. The router is flashed with DD-WRT firmware.

Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=2ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=947ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64

... Exactly one minute later ...

Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=939ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64
Reply from 192.168.1.1: bytes=32 time=1ms TTL=64

Ping statistics for 192.168.1.1:
Packets: Sent = 684, Received = 684, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 1548ms, Average = 16ms

Any ideas as to what those spikes are and how to fix?

Post by **Tormentius** » Thu Sep 28, 2006 6:27 pm

In a word? Linksys.

Seriously though, check for any other wireless devices in the immediate area of the router that could be causing interference.

Post by **+JuggerNaut+** » Thu Sep 28, 2006 6:42 pm

Tormentius wrote:In a word? Linksys.

this is where you and i agree to disagree. i've had nothing but great results using and setting up the WRT54GX.

imo, DLink is that absolute bowels of the consumer router industry. shit, shit shit.

anyway, obsid, i've also got the DDWRT firmware. are you running v23 sp1 final? have you tweaked any settings at all (xmit, ACK timing, etc)?

Post by **obsidian** » Fri Sep 29, 2006 3:17 am

Yup, v23 SP1. I've tweaked just the normal basic stuff, like encryption, port forwarding, QOS, etc. I left everything else (timings and other tweaks) DDWRT defaults.

None of my neighbours have wireless, and I only have 1 other wireless device in the house, a desktop upstairs that I rarely use.

The lag seems to occur in VERY normal intervals of 1 minute. I timed it.

I tried disabling antivirus, antispyware and pretty much all other extra applications and services. Tested ping again and same problem, so I doubt if it's some software sending out large chunks of information every minute.

Odd.

Post by **+JuggerNaut+** » Fri Sep 29, 2006 3:39 am

have you checked all outgoing connections from your pc?

command prompt then:

/netstat -b

Post by **obsidian** » Fri Sep 29, 2006 5:43 pm

Not familiar with netstat, but here's what it reports.... I ran it twice on two different occasions. First after rebooting, second after waiting for a bit.

Active Connections

Proto Local Address Foreign Address State PID
TCP p160:2869 WRT54GL:2720 TIME_WAIT 0
TCP p160:8472 WRT54GL:5431 TIME_WAIT 0
TCP p160:27453 WRT54GL:5431 TIME_WAIT 0
TCP p160:49978 WRT54GL:5431 TIME_WAIT 0

Active Connections

Proto Local Address Foreign Address State PID

Probably just stating the obvious but I'm guessing that means no outgoing connections? :icon27:

Same ping issues though.

Post by **obsidian** » Fri Sep 29, 2006 6:11 pm

Fixed! (I think/hope)

I was digging around the Linksys user forums and there was a suggestion of disabling the Wireless Zero Configuration service. So far so good.

Thanks for your help guys.

Post by **+JuggerNaut+** » Fri Sep 29, 2006 8:05 pm

nice!

Post by **obsidian** » Sat Sep 30, 2006 2:58 am

Update after some reading:

Apparently, WZC causes a couple of problems. First, if you have SSID broadcast disabled, WZC goes nuts trying to find a connection regardless of the fact that you are already connected to a hidden wireless network. Second, WZC likes to "roam" periodically, looking for better connections despite the fact that you are already connected to a perfectly stable connection. As a result, you can get lag issues everytime WZC tries do do its thing. Not necessary, thank you very much!

Enabling SSID broadcast brought my those ping spikes from around 1000 to 600 ms. Disabling WZC brings it down to a constant > 1ms.

Problem is, after disabling WZC and restarting, Windows wireless doesn't seem to work at all! So I have to re-enable it and (edit: heh, I wrote disenable) disable it, which as you can imagine is a pain in the ass.

There's a few workarounds on the net, I'm currently looking into this one and this.

If anyone has any better suggestions, let me know. But I feel good that at least I can isolate the problem now. I'll keep you guys updated on how this works out.

Post by **obsidian** » Sat Sep 30, 2006 4:32 am

Okay, so I did the following and everything seems to work perfectly:

1) Enabled SSID broadcast temporarily (so wireless card can automatically detect router).
2) Disable WZC in services.msc
3) Installed the latest Linksys WMP54G drivers and Linksys Wireless Monitor application that came bundled with the drivers. Enabled it in the system tray and configured it to recognize my router.
4) Disabled SSID broadcast again.

Hopefully, all this will help someone else down the road.