Question about "Sensitivity Range (ACK Timing)"

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tta
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PostPosted: Sat Mar 29, 2008 0:29    Post subject: Question about "Sensitivity Range (ACK Timing)" Reply with quote
What is the proper setting for "Sensitivity Range (ACK Timing)". The default is 2000 meters. Does this mean the higher the number, the stronger the signal or the other way around?
Let say my wireless repeater is 100m away from the main router. Should I set this number to around 100 or keep it at a higher number.
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cmasi
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PostPosted: Sat Mar 29, 2008 1:34    Post subject: Reply with quote
If you set the ACK timing too high, it can affect throughput (because the sender will wait too long for a response to packets that have been lost), but if you set it too low then the receiver will not be able to respond in time and the sender will assume that the connection is broken. I have my router set at 200m, but ymmv.

A quick easy test is to have a machine connected via wireless at the edge of your intended wireless network and a machine connected via ethernet. Use the wired machine to drop the ACK timing until you can't ping the wireless machine anymore. Then bump it up a bit (maybe 25-50) just to be on the safe side.
redhawk0
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PostPosted: Sat Mar 29, 2008 1:36    Post subject: Reply with quote
If the unit is communicating within a normal house...just set it to 0. It works for me. If you are trying to talk to another unit that is down the block....estimate the distance and input that number in meters to your router.

I have 8 units setup throughout the house...all set to 0 for ack timing. None give me any problems.

It has nothing to do with signal strength...it has to do with timing signals between radios. Think of it like a handshake signal.

redhawk

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tta
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PostPosted: Sat Mar 29, 2008 1:45    Post subject: Reply with quote
Thanks for the explanations.
biggy boy
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PostPosted: Sat Mar 29, 2008 1:48    Post subject: Reply with quote
Yes dito I learn something new every day here Smile




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JN
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PostPosted: Sat Mar 29, 2008 16:42    Post subject: Reply with quote
Is this feature back in v24? Starting with which build? Does it work properly?
redhawk0
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PostPosted: Sat Mar 29, 2008 16:46    Post subject: Reply with quote
JN wrote:
Is this feature back in v24? Starting with which build? Does it work properly?


Starting with the new RC6 driver builds. But...don't use RC6.X...it has wireless problems. Use one of the updated builds (9346 is the latest) in the Eko directory. NEWD contain this feature...VINT does not.

I haven't done any testing on it....I set mine to 0 always.

Give it a try and report your findings.

redhawk

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JN
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PostPosted: Tue Apr 15, 2008 1:04    Post subject: Reply with quote
cmasi wrote:
If you set the ACK timing too high, it can affect throughput (because the sender will wait too long for a response to packets that have been lost), but if you set it too low then the receiver will not be able to respond in time and the sender will assume that the connection is broken.
Would too low of ACK timing in a repeater show as a high number of transmit errors? I realize too high of ACK timing would only reduce speed of data transfer.
RD123
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PostPosted: Tue Apr 15, 2008 7:28    Post subject: Reply with quote
When set to 0 all my XP machines were fine but my vista machine would not connect at all.

Changed it to 300 and all ok.
LLigetfa
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PostPosted: Tue Apr 15, 2008 12:57    Post subject: Reply with quote
Too low is much worse than too high.
JN
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PostPosted: Fri May 02, 2008 1:08    Post subject: Reply with quote
LLigetfa wrote:
Too low is much worse than too high.
So, then, what happens if I set it to zero? I thought that would disable ACK timing, but what exactly happens when it is disabled?
GeeTek
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PostPosted: Fri May 02, 2008 2:44    Post subject: Reply with quote
JN wrote:
So, then, what happens if I set it to zero? I thought that would disable ACK timing, but what exactly happens when it is disabled?

I have tested DD-WRT V23 SP1 with a 4 mile link. It required that the ACK be set for the proper distance to achive the full 27 Mbps bandwidth. Setting the ACK to zero killed the bandwidth, which it should not have. I previously had used D-Link DWL-2100 radios for that same link. With the ACK mod for the 2100, the bandwidth was maximum at any distance, local and at 4 miles, which tells me that the D-Link was actually disabling ACK where the Zero setting in DD-WRT was not. I have not had a chance to test the newest DD-WRT builds at a distance.

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owagner
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PostPosted: Sun May 04, 2008 11:39    Post subject: Setting this to 0 on Broadcom devices... Reply with quote
After setting Sensitivity Range (ACK Timing) to "0", I had serious WLAN issues with my two broadcam based units and 24RC7 -- tcpdump showed them both to be heavily resending packets to the wireless stations.

Setting the value back to default (2000) fixed this.

It kind of looks as if "0 == disable", as suggested by the help paragraph for this setting, is not accurate, but instead would really mean "very, very low timeout".

The devices were

-- a WRT 54GS V4 (Broadcom BCM4712 chip rev 1)

and

-- an Asus WL-500g Premium (Broadcom BCM4704 chip rev 9)

Best Regards,
Olli
moreins
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PostPosted: Thu Feb 24, 2011 20:42    Post subject: Reply with quote
hello
sorry to bring this very old thread up.
i have a wrt54gs v2.1 running a VINT build (15230M). is it normal to still not see the "Sensitivity Range" option on these newer builds?

i have another router connected to this one through WDS (second floor) and runs a NEWD build. what value do you recommend me?

thanks!

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