Solved: 1242AG Multiple SSID Beacon

gilldex12 · ‎02-18-2014

Hello everyone

I'm wondering how the 1242AG handles multiple SSIDs and the beacon frame. I read that it depends on the vendor how he implements the way an AP takes care of multiple SSIDs. My question:

If I have configured 3 SSIDs, and the beacon is set to 100 kusec, does the AP send 3 times a beacon frame for each SSID every 100 kusec or are all SSIDs in the same frame? I'm confused about the different approaches of the vendors.

Thank you

Victor Vasantha Kumar · ‎02-19-2014

Hi,

Multiple Beacons has to be sent at different intervals.

IF, there are N supported SSIDs(WLANs),

AND-IF, the standard Beacon interval is ΔT,

THEN, the Beacon traffic is multiplied by N, and the interval between Beacons will be ΔT/N.

Btw... why is your name 'test'.. Do you want to change it

Regards
Victor V

*****Help out other by using the rating system and marking answered questions as *****Answered"*****

Regards Victor V *****Help out other by using the rating system and marking answered questions as *****Answered"*****

View solution in original post

Victor Vasantha Kumar · ‎02-18-2014

This is a very interesting topic to discuss. !!

There are multiple approaches to implement multiple WLANs.

One implementation uses a single BSSID and advertises all the SSIDs supported by the system on the same beacon.

Some of the issues with this approach are:

** Incompatible with most of the 802.11 clients

** Does not support different capability sets for each SSID

The industry standard is to use multiple BSSIDs, so each WLAN has its own SSID and BSSID.

Multiple beacons will be sed to advertise the SSIDs corresponding to the WLANs

We also need to understand that this type of solution will result in with increase in management traffic, which degrades in air quality and airtime availability.

The best approach is to use a single WLAN and use authorisation policies ( using ISE / ACS / IAS / NPS) for multiple types of client.

Regards
Victor V

*****Help out other by using the rating system and marking answered questions as *****Answered"*****

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gilldex12 · ‎02-19-2014

Hi Victor

Thank you for your excellent answer. Just one additional question to this topic. The beacon intervall set ist for every SSID the same. With 3 SSIDs I get 3 beacons at the same time, they are not time shifted or something that I can't configure?

Thank you

Scott Fella · ‎02-19-2014

Beacons are sent out at different time but at a given interval. You can see this if you sniff the wireless traffic.

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***

Victor Vasantha Kumar · ‎02-19-2014

Hi,

Multiple Beacons has to be sent at different intervals.

IF, there are N supported SSIDs(WLANs),

AND-IF, the standard Beacon interval is ΔT,

THEN, the Beacon traffic is multiplied by N, and the interval between Beacons will be ΔT/N.

Btw... why is your name 'test'.. Do you want to change it

Regards
Victor V

*****Help out other by using the rating system and marking answered questions as *****Answered"*****

Regards Victor V *****Help out other by using the rating system and marking answered questions as *****Answered"*****

gilldex12 · ‎02-19-2014

That was exactly what I was looking for. Thank you very much!

I registered just to see how it works here and thought I could change my name in something that makes more sense later. Unfortunately I found out that I can't simply change it in my settings. (Or at least I was unable to find the right spot) So I guess I have to live with it.

@Scott: I was already setting up my testing equipment for sniffing the beacons and then Victor replied. But thank you too for your help.

George Stefanick · ‎02-19-2014

While most reference the beacon interval at 100 us. Its really 102 us.

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