Question about statistics

Hello, I'm new to wireless and I'm tryng to see if there are any tweaks
I can do either in the client wireless software (SMC/ralink) or in the
AP(Actiontec gt704) (I'm running in windows 2000) For now, I've left
both set to 802.11 b/g mix.

Typical results I see are about 15-25 % receive crc errors,
and on the transmit side 3-10% "frames tranmitted successfully after
retry"
and 1-5 % "frames fail to receive ACK after all retries" This last
statistic
seems to drop significantly if I set B/G protection to OFF in the
client.

The wireless nic is the SMCWPCI-GM Mimo.
I think the Actiontec may be the poorer performer of the two pieces of
H/W.
It runs very hot and I'm trying to get Verizon to replace it.
The distance between the two is about 18 feet.

I'm running 64-bit WEP but no further authentification.

Thanks for any tips.
Dave

(E-Mail Removed) hath wroth:

>Hello, I'm new to wireless and I'm tryng to see if there are any tweaks
> I can do either in the client wireless software (SMC/ralink) or in the
>AP(Actiontec gt704) (I'm running in windows 2000) For now, I've left
>both set to 802.11 b/g mix.

You'll get quite a slowdown in maximum speed if you leave the 802.11b
compatibilty feature enabled. See max theoretical numbers at:
<http://wireless.wikia.com/wiki/Wi-Fi#Performance_and_Speed>
The good news is that the 802.11b compatibility performance hit only
appears when an 802.11b device connects to the access point. The
current crop of chipsets seem to be smart enough to ignore unconnected
802.11b packets. No clue if the Actiontec GT704 qualifies.

>Typical results I see are about 15-25 % receive crc errors,

Retch barf puke etc. That's awful.

>and on the transmit side 3-10% "frames tranmitted successfully after
>retry"
>and 1-5 % "frames fail to receive ACK after all retries" This last
>statistic
>seems to drop significantly if I set B/G protection to OFF in the
>client.

Well yes. That's because the access point has switched to 802.11b
mode and is seeing all the 802.11g packets as corrupted garbage or
noise. It can't decode 802.11g when in 802.11b mode. When operating,
my guess is about 25-30% airtime devoted to 802.11b packets, which
explains why about 1/4 of the arriving packets require retransmission.
This is the way it used to be before the chipset makers cleaned up the
compatibility mode.

You might see a dramatic decrease in errors and retransmissions if you
enable wireless CTS/RTS flow control in the wireless router. That
will prevent 802.11g clients from belching packets when the access
point is in 802.11b mode, and the reverse. However, flow control will
slow things down even more.

>The wireless nic is the SMCWPCI-GM Mimo.

Doesn't matter. MIMO on the client end only works with a compatible
MIMO router. As far as the wireless routers are concerned, it's an
ordinary 802.11g client.

>I think the Actiontec may be the poorer performer of the two pieces of
>H/W.

Yep. I think you need to borrow a more modernish wireless router and
compare statistics. I think you'll find them less disgusting.

>It runs very hot and I'm trying to get Verizon to replace it.
>The distance between the two is about 18 feet.
>
>I'm running 64-bit WEP but no further authentification.
>
>Thanks for any tips.
>Dave

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff, Thanks for answering my message.
I've got further questions based on your response and my lack of
understanding in wireless networks.


On Mon, 22 Jan 2007 23:21:55 -0800, Jeff Liebermann
<(E-Mail Removed)> wrote:

>(E-Mail Removed) hath wroth:
>
>>Hello, I'm new to wireless and I'm tryng to see if there are any tweaks
>> I can do either in the client wireless software (SMC/ralink) or in the
>>AP(Actiontec gt704) (I'm running in windows 2000) For now, I've left
>>both set to 802.11 b/g mix.
>
>You'll get quite a slowdown in maximum speed if you leave the 802.11b
>compatibilty feature enabled. See max theoretical numbers at:
><http://wireless.wikia.com/wiki/Wi-Fi#Performance_and_Speed>
>The good news is that the 802.11b compatibility performance hit only
>appears when an 802.11b device connects to the access point. The
>current crop of chipsets seem to be smart enough to ignore unconnected
>802.11b packets. No clue if the Actiontec GT704 qualifies.

Would it be wise to set the AP and NIC to 802.11g only?

>
>>Typical results I see are about 15-25 % receive crc errors,
>
>Retch barf puke etc. That's awful.
>
>>and on the transmit side 3-10% "frames tranmitted successfully after
>>retry"
>>and 1-5 % "frames fail to receive ACK after all retries" This last
>>statistic
>>seems to drop significantly if I set B/G protection to OFF in the
>>client.
>
>Well yes. That's because the access point has switched to 802.11b
>mode and is seeing all the 802.11g packets as corrupted garbage or
>noise. It can't decode 802.11g when in 802.11b mode. When operating,
>my guess is about 25-30% airtime devoted to 802.11b packets, which
>explains why about 1/4 of the arriving packets require retransmission.
>This is the way it used to be before the chipset makers cleaned up the
>compatibility mode.

Why is the AP switching to 802.11 b? Because the retries are high?

What setting do you recommend then?
What about the "B/G protection to OFF" setting in the NIC
How should it be used? Placing it on AUTO gives all the retries while
setting to off mitigates them somewhat.
>
>You might see a dramatic decrease in errors and retransmissions if you
>enable wireless CTS/RTS flow control in the wireless router. That
>will prevent 802.11g clients from belching packets when the access
>point is in 802.11b mode, and the reverse. However, flow control will
>slow things down even more.

I am unable to find this setting in the AP.
There does seem to be something similar in the Nic
config program
>
>>The wireless nic is the SMCWPCI-GM Mimo.
>
>Doesn't matter. MIMO on the client end only works with a compatible
>MIMO router. As far as the wireless routers are concerned, it's an
>ordinary 802.11g client.
>
>>I think the Actiontec may be the poorer performer of the two pieces of
>>H/W.
>
>Yep. I think you need to borrow a more modernish wireless router and
>compare statistics. I think you'll find them less disgusting.
>
>>It runs very hot and I'm trying to get Verizon to replace it.
>>The distance between the two is about 18 feet.
The replacement modem arrived today.
It has an updated firmware, so I'm hoping for the best

>>
>>I'm running 64-bit WEP but no further authentification.
>>
>>Thanks for any tips.
>>Dave

Thanks again for your help.
Unfortunately, at this point, I don't know enough about the subject
to know if I even asking the right questions!
Dave

dave xnet <(E-Mail Removed)> hath wroth:

>Would it be wise to set the AP and NIC to 802.11g only?

I keep running into 802.11b only clients all the time. For example,
my fairly new Verizon XV-6700 cell phone only does 802.11b. So, I'm
stuck with 802.11b compatibility mode on. I'm really tempted to
install two access points, one for each mode so that the 802.11b stuff
doesn't slow down the 802.11g traffic. You might try it temporarily
off to see what it will do for your performance and error rate.

>Why is the AP switching to 802.11 b? Because the retries are high?

Why? Because some programmist told the AP to do it. In the bad old
days, the AP would simply time slice between 802.11b and 802.11g. It
would spend about 1/4 of it's time listening for 802.11b signals,
which guaranteed a 25% speed reduction even if there were no 802.11b
signals worth listening for. This was correctly judged as a really
dumb way of doing this, so better algorithms were invented. The
current fashion is to sample for 802.11b signals about once every 5
seconds. If it hears valid 802.11b data, it increases the sampling
rate and window time depending on traffic. My guess(tm) is that your
Actiontec GT704 is using something closer to the original algorithm.

>What setting do you recommend then?

I believe I recommended a few tweaks in my previous posting. Please
don't make me re-read my own postings. I just hate doing that.

>What about the "B/G protection to OFF" setting in the NIC
>How should it be used? Placing it on AUTO gives all the retries while
>setting to off mitigates them somewhat.

Dunno. It's the same issue as the access point. The client treats
the other mode as noise or errors. Either way, they show up on the
statistics as errors of sorts, while the radios just sit there waiting
for data that will never arrive in a mode that you're not using. If
all your wireless devices are 802.11g, then turn off 802.11b in
literally everything, and the errors should evaporate.

>I am unable to find this setting in the AP.

It's usually called just "flow control". It's often next to
"fragmentation threshold". I'm too lazy to read the manual and find
the page.

>There does seem to be something similar in the Nic
>config program

It really shouldn't be in the NIC. In infrastructure mode, the access
point runs the show and determines the protocols, channels, speeds,
and such. The client radio just accepts whatever the access point
delivers.

>The replacement modem arrived today.
>It has an updated firmware, so I'm hoping for the best

Is that another Actiontec GT704?


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Wed, 24 Jan 2007 10:37:38 -0800, Jeff Liebermann
<(E-Mail Removed)> wrote:


>>I am unable to find this setting in the AP.
>
>It's usually called just "flow control". It's often next to
>"fragmentation threshold". I'm too lazy to read the manual and find
>the page.
>
>>There does seem to be something similar in the Nic
>>config program
>
>It really shouldn't be in the NIC. In infrastructure mode, the access
>point runs the show and determines the protocols, channels, speeds,
>and such. The client radio just accepts whatever the access point
>delivers.

This makes sense. However, in the gt704, I can find nothing
relating to flow control at all. I have searched the 192.168.1.1
config pages, as well as the pdf manual.
The only reference I can see in the manual is this sentence,
in the 'features" section at the beginning:
"Flow control support for Fast Ethernet"
>
>>The replacement modem arrived today.
>>It has an updated firmware, so I'm hoping for the best
>
>Is that another Actiontec GT704?
Unfortunately yes.
One things I could do is run it in Bridge mode
and connect another router/AP to it.

Plenty of Netgear and similar ads. in the Sunday papers.

Thanks for your pointers!
Dave

On Wed, 24 Jan 2007 22:30:52 GMT, dave xnet
<(E-Mail Removed)> wrote:

>This makes sense. However, in the gt704, I can find nothing
>relating to flow control at all. I have searched the 192.168.1.1
>config pages, as well as the pdf manual.
>The only reference I can see in the manual is this sentence,
>in the 'features" section at the beginning:
>"Flow control support for Fast Ethernet"

That's a different from of flow control. The one I'm refering to is
to reduce collisions and contention issues with the wireless part, not
the ethernet. Another name for it is "RTS Threshold". It's usually
right next to "Fragmentation Threshold". It's a manditory part of
802.11 and I have yet to see a wireless access point that lacks this
feature. The WRT54G and DI-624:
http://www.linksysdata.com/ui/WRT54G/v5/1.00.6/WAdv.htm
http://support.dlink.com/Emulators/d...rform_11g.html
both have it as "RTS Threshold".

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

On Wed, 24 Jan 2007 21:07:21 -0800, Jeff Liebermann
<(E-Mail Removed)> wrote:

>On Wed, 24 Jan 2007 22:30:52 GMT, dave xnet
><(E-Mail Removed)> wrote:
>
>>This makes sense. However, in the gt704, I can find nothing
>>relating to flow control at all. I have searched the 192.168.1.1
>>config pages, as well as the pdf manual.
>>The only reference I can see in the manual is this sentence,
>>in the 'features" section at the beginning:
>>"Flow control support for Fast Ethernet"
>
>That's a different from of flow control. The one I'm refering to is
>to reduce collisions and contention issues with the wireless part, not
>the ethernet. Another name for it is "RTS Threshold". It's usually
>right next to "Fragmentation Threshold". It's a manditory part of
>802.11 and I have yet to see a wireless access point that lacks this
>feature. The WRT54G and DI-624:
>http://www.linksysdata.com/ui/WRT54G/v5/1.00.6/WAdv.htm
>http://support.dlink.com/Emulators/d...rform_11g.html
>both have it as "RTS Threshold".
I can't find any sign
of it. Perhaps it's hidden somewhere.
There's really only two pages to the wireless setup in Verizon's gt704
Under basic I see:
wireless on/off
ESSID
Channel #
WEP on/off
Select WEP key/Key length

Under Advanced I see:
Security - choice of WEP, WEP+802.1x or WPA
ESSID broadcast on/off
Wireless MAC authorization
802.11b/g mode.

Thats' all I see.
It's a mystery.
Dave