Enable 802.11n HT (Greenfield)?

[mscherting]

Hi all.

I've just been tasked with setting up 19 AIR-CT2504 WLCs with AIR-CAP3502E APs.  The primary objective is to maximize throughput from clients uploading LARGE files over the air.

I need to make sure I config HT 802.11n properly with no support for legacy clients in the 5Ghz band.

Any tips or a check list?

Thanks!

[George Stefanick]

The problem is even if you enable greenfield if you are neigbors with 802.11a/n networks your network will suffer. So the question is, do you have neigboring networks in range of your wifi ?

__________________________________________________________________________________________
"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."

[mscherting]

Most likely there will be neighboring 5Ghz networks at most locations, some of which I control.

[George Stefanick]

If the networks are close, with in 20db you could suffer issues. 802.11n inroduced 3 PPDUs.

Leagcy

Mix

Green Field

Almost all networks run mix. if you run green field all your client would need to support 802.11n. Also you design would need to support data rates and cell sizes. But again bigger issue is your neigbors. If a 802.11a client starts to trigger frames your green field will feel it ..

__________________________________________________________________________________________
"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."

[mscherting]

Let's assume I control neighboring 5Ghz networks and can shutdown the 5Ghz radios if necessary.

I have been assured that all the clients are fully 5Ghz 802.11n HT capable.    We'll see.

Design: outdoor parking areas, probably without much multi-path.  Initially only one AP per site.  I won't be allowed to survey the sites.

[George Stefanick]

After looking at the controller and the rates, it doesn't appear you can check box one of the MCS rates as mandatory. One rate at least has to be mandatory. Let me poke around

__________________________________________________________________________________________
"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 · Accepted solution]

This document talks about 802.11n (cisco)

http://www.cisco.com/en/US/products/ps6366/products_tech_note09186a0080a3443f.shtml

Here is another conversation on the same subject of man rates

https://supportforums.cisco.com/thread/330927

This is a good one ..

I don't know if the WLC supports pure greenfield. I dont see a way you can mandatory one of the MCS rates. Perhaps Scott, Leo or Steve can comment ..

Still digging ..

__________________________________________________________________________________________
"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."

[mscherting]

Thanks George!  Good reads.  At least with dedicated WLCs at each site vs. H-REAP I can put tighter constraints on clients even if I can't enforce pure Greenfield n.

Waiting for the 2504s to arrive...

[Leo Laohoo]

Here's my opinion ...

If you are trying to push LARGE FILES around and you want high speed, using a 2500 is not going to be a wise decision because the 2500, which as FastEthernet ports, will become your bottleneck.  If I was to make a choice, I will always choose a 5508.

In regards to high speed, have you purchased your AP yet?  If not, then think about looking at the 3600 with the 802.11ac (wave 1) optional module. 

[George Stefanick]

Leo, you can lag the 2500 with the latest code, right ?

Sent from Cisco Technical Support iPad App

[Leo Laohoo]

Yes.  Latest 7.4.100.0 will allow lag, but still 19 units 3500 and you're WLC is a 2500 ... Still doesn't sit well with me.

[Scott Fella]

You guys arguing like a married couple:)

Well the 2504 is gigabit and like George mentioned it does support LAG on v7.4. The max throughput with LAG enabled is 2 gigabit, without lag, it is 1 gigabit. I have had issues with LAG on the 2504 and pings dropping though but only had one 2504 to play with. When I disable LAG, I don't run into any issues. This could be because my WLC has been through many beta codes, but just look out just in case you run into an issue with connectivity with LAG enabled on a 2504.

Sent from Cisco Technical Support iPhone App

[mscherting]

Thanks for the input guys.

I haven't even looked into LAG for this yet.

7.4 will be a pain because I'm still at NCS 1.1.1.24 which doesn't play well with 7.4.

This will be 19 discreet WAN edge sites, each with a dedicated 2504 and one or more 3502E's, per customer specs/request.

I must also upgrade switches at several sites from Fa to Gi.

Large files are to be moved from clients to local SANs only, not over the WAN.

[Leo Laohoo]

7.4 will be a pain because I'm still at NCS 1.1.1.24 which doesn't play well with 7.4.

Not it won't.  I've got two WiSM-2 running 7.4 and I'm still "stuck" in WCS 7.0.220.0.

[Scott Fella]

Leo is one of the lucky ones that it still works:)

Sent from Cisco Technical Support iPhone App