Wireless Access

Hello,

I read the description for Basic and Transmit rate from manual but I did not grasp what is doing what and what is the effect ?

"What exactly the function/effect of Transmit Rate and Basic Rates on Clients and Tx/Rx Rates ?"

Also, is BSS Max idle period is same as Time out fiesld in SSID profile ?

However, if it is the same, Time out is not working as expected !! because I can see clients time keeps increasing.

BSS Max idle period: A time period during which the access point (AP) does not disassociate a station
(STA) due to nonreceipt of frames from that STA.

Thanks.

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@Abi wrote:

Hello,

 

I read the description for Basic and Transmit rate from manual but I did not grasp what is doing what and what is the effect ?

 

"What exactly the function/effect of Transmit Rate and Basic Rates on Clients and Tx/Rx Rates ?"

 

Also, is BSS Max idle period is same as Time out fiesld in SSID profile ?

 

However, if it is the same, Time out is not working as expected !! because I can see clients time keeps increasing.

 

BSS Max idle period: A time period during which the access point (AP) does not disassociate a station
(STA) due to nonreceipt of frames from that STA.

 

Thanks.

---

That is three questions in one post, so I have an question about the last one:

Please describe the issue with the clients time keeps increasing....

Hi Colin,

When I set the value of Station-Time out to say 1 min, and when I connect a user and keep refresh the Client monitor on controller I disconnect the client (by shutting switching the wifi button to off) however the client time value in controller (from Client Monitor) keeps increasing (for some time though) but still exceed the Station Time out value in SSID profile.

This does not affect my network but I thought that the controller should disconnect the client from db if his ideal time exceeded Station Time-out.

(unless the time showing in the Client-Monitor refer to something else).

Under the SSID profile, those are 802.11 timers.  They are unrelated to how long a user is kept in the user table, which is what you are looking at.  You can shut off your laptop right now, but how long it is kept in the user table is defined by the user idle timeout value (default 5 minutes) here:  http://community.arubanetworks.com/t5/Command-of-the-Day/COTD-AAA-Idle-Timeout-and-Authentication-Server-Dead-Time/m-p/106/highlight/true#M45

I see this is a good information, so:

Station Ageout Time: Time, in seconds, that a client is allowed to remain idle before being aged out.

and BSS max idle time are the same thing ?

Station ageout time: if occured client will not be served by AP unless it is reassociated (save power/ management for APs)

DB Client Timeout: if timeout client will required to re-authenticate.

so to relate them with client time  in db we can say:

A- If Station ageout time = db client time-out:

Station will be required to re-associate and re-authenticate.

B- If Station ageout time > db client time-out:

Station will be required to re-associate and re-authenticate (because he is deleted from db it is like it is also like station agedout).

C- If Station ageout time < db client time-out:

Station will be required to re-associate but no authentication required (reduce AP management for clients).

Is my understanding correct ?!

Hello Abi

About the other 2 questions that got unanwered

What are the basic rates and transmit rates?

Well the basic rates are the rate that all the clients need to support to connect to the AP.(it was it get advertised on beacon frames and probe response)

In this case the default is 1 & 2 because come very old 802.1b clients will just associate if they are advertising 1 &2 otherwise they wont conncect thats why i guess aruba put it as default.

Now for the transmit rate

This is used so when the client connect which speed they can use... sometimes when clients are really far  and let say you got in transmit rate 1,2.6 blah blah blah, they will be able to transmit at 2mbs if they are really far away to trade off speed for more realible connection.  Sometimes you want to turn off the slow rates of transmitions because as you know just one client can transmit in the medium at once, in  this example let say you got a slow client transmitting at  1mbs because he is far... then he will make your network slower as he will need to spent more time in the air to transmit his packets.   You get the idea now?

At least is how i understand it.

Hi NightShade,

I want to discuss Basic rates for now, based on the above table which I assume it is correct. Also, we know that in SSID profile we have 11g basic rates and 11a basic rates, which means that 11b clients included with (11g).

"The Basic Rate Set contains the rates that all devices in the cell must support; it is a sub-set of the Transmit Rate Set.  All control, multicast, and broadcast packets are  transmitted using one of the Basic Rates (as defined by the IEEE 802.11 standards)."

I need confirmation on the following for better understanding:

1- If basic rate is set to (1 and 2) -(11g only) clients will not be able to associate.

2- If basic rate is set to (1, 2, 5.5 and 11) -(11b only)client will not be able to  associate.

3- If basic rate is set to (5 and 11) 11b only and 11g clients will not be able to associate.

4- BR will not affect coverage.

But what effect will Basic Rates of ( 1 and 2), (5 and 11), (2 and 5) and (1, 2, 5 and 11) make on clients/APs association or performance ?!

Ill asnwer you as i understand it

But what effect will Basic Rates of ( 1 and 2), (5 and 11), (2 and 5) and (1, 2, 5 and 11) make on clients/APs association or performance ?!

It should have no effect  the peformance as its the mandatory rate that it need to connect.

1- If basic rate is set to (1 and 2) -(11g only) clients will not be able to associate.

they should be able to associate.... 802.11g is backward compatible with 802.11b... so for example a g only client can associate to a b only ap

2- If basic rate is set to (1, 2, 5.5 and 11) -(11b only)client will not be able to  associate.

They should be able to connect as you select a basic rate they support

3- If basic rate is set to (5 and 11) 11b only and 11g clients will not be able to associate.

gclients should be able to connect but the b cients im not sure... i guess he will be able to connect but you are putting that it must connect to the maximum speed... i dont really have b only cards to test.... so dont know.

4- BR will not affect coverage

It shoud not affect the coverage as this is just the mandatory rates that the client must support to connect

Anyways that is how i understand it, did i really make test on this ? no.... but a while ago  asked myself  similar questions and i started reading about it and that was my conclution.
Collin dont just kudo it we need your vast knowledge :)  it would be nice if you can confirm what i m saying  or at least give you opinion!

Hi NightShed,

for all my cases (1,2,3)  the clients can associate. But from the definision of basic rate use.

" Well the basic rates are the rate that all the clients need to support to connect to the AP.(it was it get advertised on beacon frames and probe response)". From the table I provided ( I am not sure how much it is correct) the basic rate is just a subset of Tx Rates, and I think you judged the total available rates (including Tx rates). If all b only , g-only and b/g are able to associate to each the possible cases I provided then why we have an OPTION to configure the basic rates ?!

In addtion, from Spectralink document they modified the basic rates for 11g set on ARUBA controller to only (5 and 11) Why they did so if it has no effect on client association or client performance ?!

one last note, I do not know what is the difference in the table between (11g only) and (11g wifi).