Cisci 1552, Cisco 1310 co work problem

[telmuun1221]

hi,

i`m using some Cisco 1552E and Cisco 1310 for outdoor wifi. but most of the clients go to 1552e even though there is good signal for 1310. for example sometimes 1552e got around 40 client and 1310 get only 10.

i configured load balance with Client window size=3, maximum denial count=3, but still not good.

outdoor area is crowded in 2.4Ghz spectrum, but does that affects this problem? any ideas balancing clients to APs?

thanks,

[George Stefanick]

Hi Telmuun

Welcome to CSC!

So load balalance in theory is great, but it doesnt work. I know you're asking HUH? When load balance is enlabled a client will probe say 2 aps   . If the controller wants the client to attach to AP2 when it receives the probe request the response from the controller will be a reason code 17. This code tell the client " hey we are full go away".  Some clients abide by this while others ignore this reason code and still send request. The controller will say heck with it and let him on..

This is what you are seeing.

Does that make sense?

Client make the roaming decision. You and influce the client by playing with the TX power on the devices, antennas, or ap placement.

Does this help ?

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[telmuun1221]

Thank you George,

That explains great about Cisco load balancing.i haven`t analyzed packets yet but that seems like what is going on.

i`m not sure about lowering antenna powers because most channels, like 1,2,4,6,8,11 are used and 1,6,11 has 3+ APs on them. i tried to fix poor throughput and client disconnection with high power, but it seems not going well as i planned. Any other ideas how to deal with it?

and i`m wondering if there any particular reason why clients choosing 1552?

Thanks again,

Telmuun

[George Stefanick]

Higher TX power and more aps are the opposite of what you want to do. You want smaller cells lower power. Also turn off the lower rates like 1 , 2 PHY rates. If a client connects at the edge of the cell and sends a frame at 1 PHY rate EVERYONE on the channel cant talk.

Its likely the the 1552 is louder and this is why the clients like him ..

You have to remember... Say you neighbor is have a kick a$$ party and blasting some great music. And your other neighbor is having a party and is playing some soft tunes, but not very loud. What party would you want to go to ?

Client probe on every channel and wait for a probe response. They build client tables. From these tabels the clients decides what AP it wants to join.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[telmuun1221]

Thanks to you i get clearer idea,

But turning power down makes some coverage holes. do you think adding access points in this area will help client balancing and winning at crowded channels?

I can`t think good way to win at spectrum. I wonder Addin APs and  putting them to lower power makes our performance better?

Many thanks.

[George Stefanick · Accepted solution]

A solid network starts with a solid design.

If you have other neighboring access points. You want to keep a few things in mind. If ap is on the same channel as yours make sure you are 20 dBm different from theirs.

You want to create small cells and add APs to fill in the gaps. Also turn off the lower rates PHY 1, 2 ..

I recently work on a project in NYC and did exactly this .. it went from not working to working exceptionally well.

If you find any of this helpful click a few of those stars and support the rating system.. it helps others navegate to post with ratings to get answers to their questions..

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[telmuun1221]

hi George, of course i will click stars to your great support.

But still i have more questions, please answer me if you have time.

By more 20dBm you mean that if our neighbor has -70dBm, we want to be on -50 on most of our coverage? i think for that we need to increase power?

Is there any other way to win crowded channel with lesser budget cost?

Thanks, i will add more stars to your answers

[George Stefanick]

You need to think like a wireless client.

Say you have 2 APS -- 1 ap you own AP1. 1 ap your neigbor owns AP2. If both Aps are on the same channel they need to abide by CSMA-CA. Wifi is a half dulpex medium. It means ONLY 1 client can trigger a frame at a time even though you dont own the neigbor ap they still share the medium ..

If you stand at the edge of your cell you need to allow your clients to hear your APs. If you check your signal and you see 70 dBm your neigbor should be 20 dBm further away in this case 90 dbm. If you are next to your ap and you see 40 dBm you should see them at 60 dBm.

Why do you ask? 20 dBm is the sweet spot for almost all clients. If your APs is at 50 and neigbor is at 55. Your client will need to halt traffic when the neigbor is sending and he will need to halt traffic while you send. Impacting both networks.

Again this is for same channel.

If your neigbor AP is on channel 2 and you are on channel 1. Your AP will see the neigbor ap as noise.

I would take the aps you have. Lessen the power by 1/2, turn off 1 , 2 PHY rate. Do a walk survey and map the area.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[George Stefanick]

And no .. Remeber if you increase power you are adding a larger coverage area. Exmaple --

say you Tx at 100mw and you have 10 clients attached. all 10 need to use the same channel

say you Tx at 300mw and now you have 40 clients . all 40 clients need to use the same channel

ONLY 1 client can trigger a frame at a time ..

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[telmuun1221]

Thank you for your great answers,

i`ll update my answer when i get more APs and decrease power.