# Wireless Access

Contributor I

## Meaning of Airtime Limit - Aruba Instant

Hello,

Im trýing to understand what´s the real meaning for the airtime limit on a per SSID basis. It appears as a percentage of time, but which "time"?

If we talk about having for example 2 SSIDs, I imagine selecting the percentage of time would be distributing the time amongst each SSID. For example 70% and 30%, so the first SSID would transmit and receive 70% of the total time and the other one on the other 30%.

But when i can chose 70% in one SSID and 80% in the other one...

So the percentage refers to what?

Guru Elite

## Re: Meaning of Airtime Limit - Aruba Instant

Colin Joseph
Aruba Customer Engineering

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Contributor I

There it goes

Guru Elite

## Re: Meaning of Airtime Limit - Aruba Instant

That airtime is enforced only when the radio is congested.  When that happens, that SSID is limited to 30% of the airtime that the radio spends on traffic.

Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Contributor I

## Re: Meaning of Airtime Limit - Aruba Instant

cjeseph,

If I understood correctly, when there is air congestion, the AP limits the total air time for that band to the % specified in that field. In this case, the total % of the sum of all SSIDs shouldn´t exceed 100%. For example, if I have 3 SSIDs, I should be able to specify, 20, 50, and 30%, but shouldnt be able to configure 50, 50 and 30. Well this happens, and one can specify % for each SSID and there is no rule that doesnt let you select more than 100% total... so I dont understand the way it works.

Is my understanding correct?

Thanks!

Guru Elite

## Re: Meaning of Airtime Limit - Aruba Instant

It is correct and it is rarely used.  It could be used for an enterprise that would like to provide priority for an SSID when there is congestion by restricting others.  In reality, that would normally be needed when there was limited bandwidth.  If there is not limited bandwidth, this is not needed, as it could drop or delay critical traffic.

Colin Joseph
Aruba Customer Engineering

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Contributor I

## Re: Meaning of Airtime Limit - Aruba Instant

Cjoseph,

There is something that is not correct here... why is it possible to select different airtime limits which the sum gives more than 100% of total airtime? The sum of all the SSID limits should never be more than 100%.

Guru Elite

## Re: Meaning of Airtime Limit - Aruba Instant

The sum is simply not checked for that parameter.  I don't know why.

Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Guru Elite

## Re: Meaning of Airtime Limit - Aruba Instant

In my opinion, this is not a very effective way to manage bandwidth, but it was included as an option for users, regardless.

Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base