Large File Transfers...at the end of my rope

Hello all, TIA for any replies to this post. I'm getting frustrated
with my WLAN's reliability, and have a question geared toward those
with wireless experience and expertise.

PROBLEM:
WLAN connection drops during large file transfers, local and internet
alike. Reconnects after short pause. Changing Fragmentation Threshold
values don't seem to help too much.

SYSTEM SPECS:
Access point - SMC SMC2755W EZ Connect 802.11a
PCI Card - DLink DWL-ab520 operating in 11a (obviously)
PC - AMD XP 2000+, Win2000 SP4, running ZoneAlarm Pro

LAN SPECIFICS:
Cable internet connection, routed through Linksys's most popular
router. Two other PCs with wired connections. My PC has wireless
connection through the AP. I'm the only wireless.

AP and its antennas have Line Of Sight to PCI card's antenna. Distance
is approximately 60 feet (plus or minus 10 feet, I'm bad with
distances). Antennas all standing vertical.

DETAILS:
The short of it is, my WLAN drops connection sporadically (maybe twice
an evening) during normal internet gaming or web browsing. I'm not
sure why yet. But during large file transfers, or heavy internet
activity (for example downloading a 250 MB file) 100% of the time the
connection will drop, then reconnect within 20-60 seconds.

I have tried adjusting the Fragmentation Threshold and RTS Threshold
of the CARD from the default of 2365 to various values (1500, 1000,
850, even 400).

Each time I do this I make them the exact same value, then synchronize
these values with those of the AP, so the CARD and AP always have the
same 4 values for these 4 fields--(note, I'm not sure if this is what
SHOULD be done, I just do it). Though this does increase the stability
somewhat, inevitably the connection drops regardless of the value
combinations.

Has anyone experienced similar instability with large transfers, even
after adjusting FT and RTS Threshold values? Any advice? Gripes? I've
been searching high and low and haven't found anyone talking about a
consistent connection problem coorelated to large file transfers.

Thanks again!!

Have you tried changing the channel you're using? You might have some
interference in the area.

"bradford" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Hello all, TIA for any replies to this post. I'm getting frustrated
> with my WLAN's reliability, and have a question geared toward those
> with wireless experience and expertise.
>
> PROBLEM:
> WLAN connection drops during large file transfers, local and internet
> alike. Reconnects after short pause. Changing Fragmentation Threshold
> values don't seem to help too much.

First go to Windows Update and go through all of the updates looking
for what's relevant, and then check for new drivers for everything
involved. There is an issue, I believe it is with Windows XP but my
memory is fuzzy, that causes that exact problem with large file
transfers




On 26 Aug 2003 08:27:20 -0700, (E-Mail Removed) (bradford) wrote:

>Hello all, TIA for any replies to this post. I'm getting frustrated
>with my WLAN's reliability, and have a question geared toward those
>with wireless experience and expertise.
>
>PROBLEM:
>WLAN connection drops during large file transfers, local and internet
>alike. Reconnects after short pause. Changing Fragmentation Threshold
>values don't seem to help too much.
>
>SYSTEM SPECS:
>Access point - SMC SMC2755W EZ Connect 802.11a
>PCI Card - DLink DWL-ab520 operating in 11a (obviously)
>PC - AMD XP 2000+, Win2000 SP4, running ZoneAlarm Pro
>
>LAN SPECIFICS:
>Cable internet connection, routed through Linksys's most popular
>router. Two other PCs with wired connections. My PC has wireless
>connection through the AP. I'm the only wireless.
>
>AP and its antennas have Line Of Sight to PCI card's antenna. Distance
>is approximately 60 feet (plus or minus 10 feet, I'm bad with
>distances). Antennas all standing vertical.
>
>DETAILS:
>The short of it is, my WLAN drops connection sporadically (maybe twice
>an evening) during normal internet gaming or web browsing. I'm not
>sure why yet. But during large file transfers, or heavy internet
>activity (for example downloading a 250 MB file) 100% of the time the
>connection will drop, then reconnect within 20-60 seconds.
>
>I have tried adjusting the Fragmentation Threshold and RTS Threshold
>of the CARD from the default of 2365 to various values (1500, 1000,
>850, even 400).
>
>Each time I do this I make them the exact same value, then synchronize
>these values with those of the AP, so the CARD and AP always have the
>same 4 values for these 4 fields--(note, I'm not sure if this is what
>SHOULD be done, I just do it). Though this does increase the stability
>somewhat, inevitably the connection drops regardless of the value
>combinations.
>
>Has anyone experienced similar instability with large transfers, even
>after adjusting FT and RTS Threshold values? Any advice? Gripes? I've
>been searching high and low and haven't found anyone talking about a
>consistent connection problem coorelated to large file transfers.
>
>Thanks again!!

i have the same problem with a 3COM airconnect AP and a Compaq WL200 PCI
wireless card. the signal strength is 50%, the signal quality is 50%. When i
transfer a file of good size, the first 20 seconds bursts away at full
speed, then the speed drops right down.

i have tried changing MTU, fragmentation threshold, antennae's but i have no
success.

i have a laptop with a 3COM wireless PCMCIA card in it, and when sitting
close to the AP the file transfer problem goes away... it will happy send
700MB at full speed.

i cannot work out why, i cannot fix it. i have learnt to live with it.


"bradford" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Hello all, TIA for any replies to this post. I'm getting frustrated
> with my WLAN's reliability, and have a question geared toward those
> with wireless experience and expertise.
>
> PROBLEM:
> WLAN connection drops during large file transfers, local and internet
> alike. Reconnects after short pause. Changing Fragmentation Threshold
> values don't seem to help too much.
>
> SYSTEM SPECS:
> Access point - SMC SMC2755W EZ Connect 802.11a
> PCI Card - DLink DWL-ab520 operating in 11a (obviously)
> PC - AMD XP 2000+, Win2000 SP4, running ZoneAlarm Pro
>
> LAN SPECIFICS:
> Cable internet connection, routed through Linksys's most popular
> router. Two other PCs with wired connections. My PC has wireless
> connection through the AP. I'm the only wireless.
>
> AP and its antennas have Line Of Sight to PCI card's antenna. Distance
> is approximately 60 feet (plus or minus 10 feet, I'm bad with
> distances). Antennas all standing vertical.
>
> DETAILS:
> The short of it is, my WLAN drops connection sporadically (maybe twice
> an evening) during normal internet gaming or web browsing. I'm not
> sure why yet. But during large file transfers, or heavy internet
> activity (for example downloading a 250 MB file) 100% of the time the
> connection will drop, then reconnect within 20-60 seconds.
>
> I have tried adjusting the Fragmentation Threshold and RTS Threshold
> of the CARD from the default of 2365 to various values (1500, 1000,
> 850, even 400).
>
> Each time I do this I make them the exact same value, then synchronize
> these values with those of the AP, so the CARD and AP always have the
> same 4 values for these 4 fields--(note, I'm not sure if this is what
> SHOULD be done, I just do it). Though this does increase the stability
> somewhat, inevitably the connection drops regardless of the value
> combinations.
>
> Has anyone experienced similar instability with large transfers, even
> after adjusting FT and RTS Threshold values? Any advice? Gripes? I've
> been searching high and low and haven't found anyone talking about a
> consistent connection problem coorelated to large file transfers.
>
> Thanks again!!

I have tried 2 or 3 channels with similar results. Odd thing is, if
it's linked to channels why does the signal consistently cut on large
file transfers? Granted it will cut out every once in awhile at random
times (it is performing better lately, tho) but there's a 100% failure
rate for large file transfers.

Either something's interfering only at times I try large transfers, or
the interference always exists but only jumbles large file transfers,
or interference is not the problem. Agree?

Thoughts? Thanks Aaron.


"Aaron K" <(E-Mail Removed)> wrote in message news:<xtM2b.16719$(E-Mail Removed)>. ..
> Have you tried changing the channel you're using? You might have some
> interference in the area.

I'm using Win2000, but I'll try this and report back any changes in results.

Thanks Toady.

Toady <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>. ..
> First go to Windows Update and go through all of the updates looking
> for what's relevant, and then check for new drivers for everything
> involved. There is an issue, I believe it is with Windows XP but my
> memory is fuzzy, that causes that exact problem with large file
> transfers

Please see my response to Aaron above about the interference, but I'm
curious if microwaves operate on 5 GHz signals?

I purchased 11a almost exclusively for the lack of 5 GHz household
signals (I live in an apartment and I figured this would/could be an
issue, espeically with the abundance of 2.4 Gig phones).

Again, interference is an odd culprit, due to the 100% failure rate
during large file transfers. But I'm staying open to suggestions.

Thanks Jared.

"Jared Richardson" <(E-Mail Removed)> wrote in message news:<6CU2b.28855$(E-Mail Removed) .com>...
> Google this group on spread spectrum telephones and/or old microwave ovens.
> It could be a neighbor.

What operating system do you run? Have you tried the suggestions by
Toady (windows update)?

I run Win2k SP 4

> "Matthew Webb" <(E-Mail Removed)> wrote in message news:<3f4ca5e5$0
> $23608$(E-Mail Removed)>...

yupp tried all of them. i run windows xp pro and i do have the wireless zero
configuration disabled. i also live in an appartment.


"bradford" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> What operating system do you run? Have you tried the suggestions by
> Toady (windows update)?
>
> I run Win2k SP 4
>
> > "Matthew Webb" <(E-Mail Removed)> wrote in message news:<3f4ca5e5$0
> > $23608$(E-Mail Removed)>...

As a follow-up, I should be receiving a "Netgear Model HE102 802.11a
WAP" via UPS today or tomorrow (got it from TigerDirect.com for $25!?!
Still waiting to see what the fluke was).

I'm wanting to see if it's access point based, netcard based, or third
party based. $25 was worth some peace of mind so I'll update everyone
when I give it a try...this is an annoying problem because I can't
even d/l all windows updated due to loss of connection.

Even a 7MB file gives me problems :@

bradford