Archived from groups: (
More info?)
On 27 Sep 2005 14:20:33 -0700, lunyee@gmail.com wrote:
>> Could you describe how you got latency numbers?
>
>The latency measurements were from pinging the router from the wireless
>client (ping 192.168.0.1). Pretty simple test. Of course pinging
>external sites had higher latency but the brunt of the latency was
>between the router and the wireless client. My wired client was pinging
><1ms the entire way. Resetting the router was the only option to
>restart this process and the wireless client would then ping between
>1ms-3ms, which is what I would expect.
1-3msec is normal. If it creeps up to 20-70msec, then there's
something seriously wrong. Unfortunately, I don't know exactly what.
>> How much of your upstream are you normally using?
>
>I have a 800Kbit upstream on my DSL modem. On average we're only using
>about 20KB/s up.
Bits and bytes? b=bits, B=Bytes. 20KB/sec is 160Kbits/sec. However,
that's sufficient headroom out of 800Kbit/sec to not impact the
latency very much. That's not the problem.
>Moreover, the
>wireless client wouldn't be experiencing lag to the router alone.
>54Mbit is quite a bit larger than an 800Kbit connection. It would take
>a lot to saturate that.
54Mbits/sec is the wireless connection speed, not the thruput. At
best, you'll get about 25Mbits/sec thruput with a 54Mbit/sec
connection. That's still way more than 800Kbits/sec, so again, that's
not the problem.
>In any case, I doubt the games we're playing are eating up that much
>bandwidth. I played the same game with two wired clients and the
>bandwidth did not saturate.
Well, the traffic is not going through the router section of the
DI-624 when you're playing just locally. If a local wireless client
to client game works as expected, then it's not the wireless part of
the puzzle. That leaves the DI-624 router section.
>All of the auto update features are disabled on my computer.
So much for that idea.
>> However, if reproducing the problem requires 6 hours of
>> traffic, it's going to be difficult to identify.
>Actually I can speed up the process by running a P2P app. Typically
>BitTorrent can get this reproduced in under an hour.
What's unique about BitTorrent is that it opens up as many parallel
streams as it can to move its traffic. My guess(tm) is that the
DI-624 can only handle about 32 streams before it complains.
BitTorrent might be trying to open more. If you're running it
"unchoked", it can easily open more, especially on a high bandwidth
connection. There are some clues here:
http://groups.yahoo.com/group/the_gdf/message/21143
but I won't pretent to understand all the BitTorrent unique buzzwords.
If there's a setting to reduce the number streams, connections, users,
or such, you might want to try it. My guess(tm) is that your game
might also be trying to do the same thing.
>I've seen many
>posts about people's DI624 routers being reset after consistent
>throughput, but I haven't seen that actually happen to me. It's just
>the wireless client that gets this insane latency to the router that
>kills me. I've tried 2 DI624 routers from different stores and tried
>nearly all permutations of settings (I really wanted to get it working
>
It's so damned fast.).
>
>I have tried different brands as well. Linksys is one. Those had its
>own assortment of problems (packet loss). Currently I'm back to my
>WGR614v1 Netgear router which has been surprisingly the most reliable
>wireless G router I've used. It has none of these problems. Well it
>does get the latency problem but only after 2months of use.
Have you tried a different client computah or wireless device? If
juggling all those wireless routers doesn't yield an improvement, then
it's possible that the problem is being caused by the client, not the
router. I guess you could test the client with a different setup, but
sitting at Starbucks for 6-7 hours playing games may not be a great
idea.
>I'm pretty
>sure it's something to do with DNS caching on the router as enabling
>the DNS relay on the router speeds up that process as well. But I can
>specify the DNS servers directly through the connection and I don't
>have to bother resetting the router for a couple months.
Well, that's really odd because DNS timeouts are usually around 30-45
seconds and not in milliseconds. Windoze clients also cache DNS
lookups for about 24 hours for a successful lookup and 5 minutes for a
failed lookup:
http://vlaurie.com/computers2/Articles/dnscache.htm
If that has an effect, I'm lost. I don't have a clue why the DNS
cache would affect ping latency, especially since you're pinging by IP
address which does not require a DNS lookup.
Weird...
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice Skype: JeffLiebermann
#
http://www.LearnByDestroying.com AE6KS
#
http://802.11junk.com
# jeffl@comix.santa-cruz.ca.us
# jeffl@cruzio.com