non-root wireless bridge speed issue

[rschwart]

I have a wireless bridge connecting two buildings, using Cisco Aironet 1262's. The root Bridge allows for bonding 2 channels on the A radios and talks at 40MHz, the non-root does not alloow me to do this configuration in the gui, and the band width is only 20MHz. So one side of my bridge will talk at a higher rate then the other end. Any ideas, suggestions??

Product/Model Number:	AIR-LAP1262N-A-K9
Top Assembly Serial Number:	FTX1449S3B4
System Software Filename:	ap3g1-k9w7-xx.152-2.JA
System Software Version:	12.4(25d)JA
Bootloader Version:	12.4(23c)JA
System Uptime:	29 minutes

[Scott Fella]

No... The bridges will negotiate on the modulation and since the one side is not using 40mhz, the link will only use 20mhz. Best practice would be to keep the two sides the same and only use 20mhz.

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[rschwart]

So there is no solution to the non-root to be configured to use 40mHz?

[Scott Fella]

If you have two 1262's, then you should be able to set the channel width to 40mhz. I thought you had another AP that didn't support 802.11n.

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[rschwart]

The 1262 set as the Root-Bridge has the option for 40mHz, 1262 set as the Non-Root Bridge does not have that option in the gui interface under 5GHz interface settings.I was hoping there maybe a cli command available the enable the 40mHz on the non-root ap.

[Peter Setaffy]

Hello

I have

AIR-CAP2602I-E-K9 IOS ap3g2-k9w7-xx.152-4.JB6 - Root-Bridge

AIR-CAP2602E-E-K9 IOS ap3g2-k9w7-xx.152-4.JB6 - Non-Root Bridge or Non-Root Bridge with Wireless Clients

And i cant also use 40mHz channel between both APs on 5GHZ radios.On Root is possible config 40HMZ but on Non-Root is not possible config any MHz configuration.When i look to Non-Root Bridge 5MHZ radio it use:

Channel Width - 20 MHz.
Transmitter Power - error

see the config from CLI:

Root_Bridge#sh run interface Dot11Radio1
!
interface Dot11Radio1
no ip address
!
encryption mode ciphers aes-ccm
!
encryption vlan 56 mode ciphers aes-ccm
!
ssid Test-Bridge
!
antenna gain 0
peakdetect
no dfs band block
stbc
power local 6
channel width 40-below
channel dfs
station-role root bridge
end

Non-Root_Bridge#sh run interface Dot11Radio1
!
interface Dot11Radio1
no ip address
!
encryption mode ciphers aes-ccm
!
encryption vlan 56 mode ciphers aes-ccm
!
ssid Test-Bridge
!
antenna gain 1
peakdetect
stbc
power local 6
station-role non-root bridge wireless-clients
world-mode legacy
end

I tried also change the rolle beween this APs but no change.

Peter

[Scott Fella]

Under the dot radio 1 you can use the channel width 40 command

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[Edgar Khachatrian]

I am having the same issue here....

I configured the whole thing with CLI....

Once a Access-Point is set to non-root bridge... it doesn't allow you to set channel or channel width, even through CLI

Anyone know what the reason for this is, or if there is a workaround?

[Scott Fella]

The root is the device that will have the channel. The non root will use the Handel the root has along with the power. You could set it actually but it won't take. The root bridge determines the channel.

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[Edgar Khachatrian]

Thank you for your quick respond Scott....

Just to make it clear.... Once an AP radio interface is set to non-root bridge mode, the command for "channel" and "channel width" on the corresponding radio interface disappear...

So if I understood you correctly the connection between the two bridged AP's are supposed to be on the same channel and channel width...

Channel width being same make sense....However I always thought they would have to be on different channels so they wouldn't interfere with each other..

But I guess when it comes to bridges this concept changes...

Thanks a lot..

Really appreciate your  quick respond

Ed

[Scott Fella]

Noooo the channel has to be the same!!! That is how they form a bridge link.

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[Edgar Khachatrian]

That makes sense....lol

what was I thinking...

Another question

So....there is no way to set the Bandwidth to 40 mhz?

I have set it to 40 on the root bridge, and the config shows correctly...

However when doing a "sho dot11 associations all", the associated link shows 20..

how can we fix this?

[Edgar Khachatrian]

I have set up a 5Ghz bridge with two 3502E APs.

I am getting about 20 Mbps......

power local is set to 14

[Scott Fella]

So the thing with 40mhz channel width is its really for client support and I believe that it's not supported when using bridge mode. I don't think I ever got 40mhz to work to be honest.

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[Edgar Khachatrian]

Ok...

is there any other way to increase the bandwidth on this 5 Ghz bridge? or is this normal?

2 3502E Access points with 3 AIR-ANT5135DW-R= antennas....

Power set to 14 and they are 20 feet apart (not too far).

I have also tried this Terra-wave antennas with the same results

http://www.terra-wave.com/shop/80211n-245-ghz-3-dbi-mimo-above-ceiling-mount-omnidirectional-antenna-with-rptnc-plug-connector-p-915.html