Erratic ping over wireless (Lenovo Vista SP1 Image issue?)

[jimsingh]

Hello,

I have three thinkpads infront of me. T61, X61, Z61. Both the T and the X are about 2-3 weeks old and shipped with Vista SP1. The Z is a year old and has XP on it. The T has a 3945 ABG wireless adapter, the X a 4965 AGN and the Z an atheros ABG adapter.

From the stock Vista SP1 image (T and X series) ping over wireless looks like this to my router:

Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
Reply from 192.168.1.1: bytes=32 time=4ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64

Solid. However, ping to a internet based site is erratic on both the X and the T (this only happens when time > 50 or 60 ms).

Reply from 128.253.161.221: bytes=32 time=88ms TTL=240
Reply from 128.253.161.221: bytes=32 time=114ms TTL=240
Reply from 128.253.161.221: bytes=32 time=139ms TTL=240
Reply from 128.253.161.221: bytes=32 time=151ms TTL=240
Reply from 128.253.161.221: bytes=32 time=182ms TTL=240
Reply from 128.253.161.221: bytes=32 time=98ms TTL=240
Reply from 128.253.161.221: bytes=32 time=124ms TTL=240
Reply from 128.253.161.221: bytes=32 time=135ms TTL=240
Reply from 128.253.161.221: bytes=32 time=150ms TTL=240
Reply from 128.253.161.221: bytes=32 time=174ms TTL=240
Reply from 128.253.161.221: bytes=32 time=304ms TTL=240
Reply from 128.253.161.221: bytes=32 time=82ms TTL=240

First reaction - the Internet can have weird ping times or you may have a transfer going that is causing skewing your ping times. That's what I thought too - BUT.

1) when I plug in over wired to my router I get a steady ~70ms ping (on both the X and the T)
2) when I ping from the Z (over wireless) I get a steady ~70 ms ping time
3) When I boot the T using a linux live cd I get a steady ~70 ms ping (over wireless and wired)
4) when I formatted my X and installed from a clean vista CD I get a steady 70ms ping (over wireless and wired) (I have not installed Vista SP1 yet, I'll do that next)
5) removing nearly every installed update and program from the T had to no effect, again this is a completely clean image from Lenovo.

I've tried this ping experiment on 4 different routers at 3 different locations. From what I can tell it is not a router issue. It is not an Internet issue. Also, the issue is new-ish. I have access to a 3 month old X series and this problem does not occur.

Can any one else confirm this behavior on a Lenovo machines that is less than 4 weeks old (shipped with Vista SP1)? This only happens when pinging and Internet site with a ping time over 50 ms over a wireless interface. I am personally pinging www.cornell.edu, but any site with a ping time over 50 ms will work (try google or yahoo).

[Harryc]

I am getting a Z61T in a couple of days so I can try this for you. Meanwhile, this is on my T30 running Linux. Thinkpad Atheros b/g. I am much closer to Cornell that you are

harryc@linux-nk2r:~> ping www.cornell.edu
PING cfprod2.cit.cornell.edu (128.253.161.221) 56(84) bytes of data.
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=1 ttl=238 time=41.8 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=2 ttl=238 time=41.5 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=3 ttl=238 time=42.8 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=4 ttl=238 time=42.6 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=5 ttl=238 time=44.2 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=6 ttl=238 time=44.6 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=7 ttl=238 time=47.3 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=8 ttl=238 time=43.0 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=9 ttl=238 time=43.2 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=10 ttl=238 time=42.7 ms
64 bytes from cfprod2.cit.cornell.edu (128.253.161.221): icmp_seq=11 ttl=238 time=41.9 ms

--- cfprod2.cit.cornell.edu ping statistics ---
11 packets transmitted, 11 received, 0% packet loss, time 10003ms
rtt min/avg/max/mdev = 41.591/43.273/47.349/1.591 ms

[jimsingh]

Quick update - I installed SP1 on Vista and all updates. My X works fine. However, the T still has problems even after removing all software and updating the wifi driver from intel.

[LIVE4SPD]

have you looked into this...

run "netsh interface tcp set global autotuninglevel=disabled"

(In order to reenable autotuning, run “netsh interface tcp set global autotuninglevel=normal”.)

http://support.microsoft.com/kb/932170

Also you can remove remote differential compression in the windows features of "Programs & Features)

Those 2 items have helped network performance a lot for me.

[jimsingh]

I installed Vista from scratch and the problem completely went away. I even applied all updates and patches and the erratic pings never came back. If I restore from the lenovo installation media, the problem comes right back.

I'm surprised that others are not reporting this same issue. It has caused choppy streaming audio/video on both systems and I'm certain that it is a lenovo image problem introduced in the past few months.

[jdhurst]

@jimsingh - Helpful post. I have a T61p with Vista Business 64-bit, and wireless is somewhat erratic. Disabling autotuning help a bit (but did not eliminate the problem). Tweakmaster helped somewhat as well but not complete.

Based on your post, I think I may call Lenovo support.
... JDH

[jimsingh]

I tried calling Lenovo Support and they were not very helpful. I didn't push the issue much because I had a backup solution (re install Vista). However, my last X61 had a bad wifi card and replacing it fixed my ping issue, so that could also be your problem. I ordered a replacement wifi card for this X, but it did not fix the issue.

Also, I said the ping was erratic, but that's not quite true. It followed a distinct pattern. 70ms, 90ms, 120ms, 140ms, back to 70ms. So it was a cycle of sorts. I also compared directly to wired mode and found wired was 67 ms (or so) +/- 4 ms (or so). so the problem was not my internet connection. I also tried a total of 5 wifi access points. Same issue.

Best of luck to all. If you read this, please check your own computer, it caused lots of internet related issues for me.

[jdhurst]

I replaced the wireless card to no avail. I keep working away on it. Wired works perfectly.

My two XP Machines (NetVista A30 and T41) work perflectly on the home network, so it is not the home network. There is some slight (less than 1 percent) chance that the router wireless firmware is the problem, and when I use my car sometime to get to a client, I will check on different wireless to confirm or deny router as the problem.
... JDH

[Wiz]

I remember i once saw a similar issue with my Thinkpad, but it happened only when running on battery. Then i found out the reason had to do with the power management of the wlan adapter.

When set to max performance which is the setting i used when connected to power i didn't have this problem, but when set to max battery which is the setting i used when running on battery i had the same problem as described here. If i changed the power settings to max performance also when running on battery i didn't see this problem anymore. In my case it didn't really cause any problems, but when i first saw the erratic ping i had to find out why.