AP Co-location

The max our download has been in the past week is 3.03M and 645k in Cacti.

So, I guess adding another 900 AP to the same tower is out of the question even with 40-60’ of vertical seperation?


What about downlink and uplink percentage?

I was at 75/25. Just changed it last week to 80/20 hoping to ease the pain.
Any thoughts?

Set the backhaul downlink % to 75% if you haven’t done so already. Even though the rel. notes list 11-50 SM’s for 2 control slots it’s not definitive. You may want to change it to 3 since each customer is set to 2Mbit down.

* Sorry, I failed to notice your post about a direct feed.

No backhaul on this tower, fiber direct.

See if you can find out if you’re hitting the pps limit in the AP. Anybody have a good utility for checking that? We’ve not run into it.

We had about 105 clients on our first AP before we split into 4 90 degree sectors. We were seeing troubles, but at twice your load.

One other thought: are you running 2x? 2x can actually increase your available bandwidth, as crazy as it sounds. Basically you can crank through twice the data per radio timeslot on the clients that can get the extra fade margin to sustain 2x. HTH.

BTW: I think the pps limit in v7 is 3000, v8 gives you 3500 or 4000, i can’t remember…

2.4 Not an option for some. It will go far better through moderate foilage compare to anything 5.x Ghz.

We run 75% 5.2 and its tree penetration is almost none, if you want reliability

Sorry, maybe I wasn’t clear. I meant 2x mode in the 900MHz radios. 1x will work for a more marginal link, because it uses 2-level frequency shift keying, and gives motorola canopy the great advantage of a radio that works with only a 3dB fade margin. 2x uses 4-level FSK and needs 10 db, but will pass twice the traffic per timeslice if you’ve got the fade margin.

Edit for misspellings… It’s getting toward late…

  1. What are you selling? Are you providing more speed to your users than you advertise? Can you turn off 2X and still meet your service levels?

    2. Are you using a CMMmicro? We noticed a dramatic improvement swapping out the CMMmicro for a Last Mile CTM and a MOXA Industrial Ethernet switch.

    3. You might be able to hit some of your semi LOS users with 2.4

    4. Hold out for 700MHz.

Thank all of you for your thoughts.

I am not sure wat pps is, is it packets per sec?
How do I check that?


Up to 3 down .5 up for $31.95/month/res and $41.95/commercial.

I just recently enabled 2x hoping to free up a little more BW.
Will turning off 2x help?
Only 8 SM’s have a strong enough sig to stay in 2x.
I don’t enable it on the SM’s unless the signals are in the -50’s.

This tower uses the older style CMM, not the micro.

We tested 2.4 with the demo kit before startup. It was ugly…

I guess I need a way to verify if the AP is maxed out.

This AP is showing a packet overload count of 685 this morning.
What exactly does this mean??

Thanks again,

Just in the time it took me to write my thoughts down here, my overload cnt has increased to 842.

What is this indicative of??

Yes, packets per second, and I’m pretty sure that’s what you’re seeing. Do you have any kind of bandwidth management tools in place? I’m guessing that you’ll find a few heavy p2p users. P2p uses lots and lots of small packets, which is probably where you’re maxing out.

2x will help, not hurt, your overall bandwidth through the canopy gear (it could increase load on your upstream if it’s not a big as the canopy bandwidth).

What are you using for your border router? You might check to see if that device has some metrics that can tell you pps on its interfaces. What about a managed switch? Metrics may be available there also.

Where are you seeing packet overload count? What version firmware in the AP?

All my AP’s are on 8.2.4
I updated them a few weeks ago from 7.3.6 due to the advertised BW gain.

This is from the AP’s statistics page:

All this in the last 5 hours

Statistics => Overload
900MHz - Access Point - 0a-00-3e-90-54-c2
Packet Overload Statistics
Total Packets Overload Count : 2127

Ethernet In Discards : 0
Ethernet Out Discards
(Statistics=>Ethernet=>outdiscards count) : 0
RF In Discards
(Sum of all VCs of: Statistics=>Data VC=>indiscards count) : 0
RF Out Discards

(Statistics=>Radio=>outdiscards count) : 2127

AS far as my Managed switch, it is a layer 3 Alcatel 7800 chasis.
I can do BW shaping per VLAN. I will have to see about the metrics data.


What’s your uptime on that AP? I’ve got one with 65days and overload count is 1783213. I don’t think we’re having any kind of a problem, though.

5 hours

Do you have a linux box between the APs and the fiber?


Cat 5 down to the CMM and there we jump on a dedicated fiber link to the Alcatel switch here at the NOC

You might want to look into something like http://www.untangle.com/. Run it in transparent bridge mode and you’ll be able to control your traffic a little better. http://www.zeroshell.net/ is another distribution that will allow you to do transparent traffic control, but their webserver seems down at the moment…

Either of those options would allow you to do some traffic shaping, and even be able to see if everybody is hitting you hard, or if you’ve got a few users doing most of your damage.

Hope that helps…