Strange packet Loss problem

Hi All,

Having never used Motorola Canopy Advantage ( 5.7GHz ) in an infrastructure deployment, we thought we’d give it a go.

Now we’ve encountered a strange problem, just when plugging in the CCM.

Basically, the link goes like this :

Orthogon <-> Orthogon —>Switch---->CCM

The switch has another 2.4GHz AP hanging off it.

So, when the CCM isn’t plugged in, the link across the Orthogons is fine and stable. As soon as the CCM is plugged in, even without the Motorola AP’s connected, the backhaul link starts dropping packets. No increase in latency, just dropping packets up to 25%.

It is mains power out there, so that doesn’t seem to be an issue. I’m assuming with no AP’s connected there shouldn’t be any interference, though the channels are far enough enyway to not make a difference I’d assume.

As soon as the ethernet from the CCM is pulled from the switch, it always, without fail, goes back to normal.

A tcpdump doesn’t show any undue traffic during this time when the CCM is connected.

Has anyone encountered this before ? Could it be doing something strange to the switch ?

It doesn’t seem to make much sense to us.

Any help would be much appreciated.

Is this a CMM or a CMMmicro?

Sorry, a CMM.

Is your switch forcing to a specific speed or will it auto-negotiate?

It does auto negotiate.

Try forcing it to 100M full and see if that stops it. It might be that the CMM and Switch are flip/flopping from once speed to another.

Hi Jerry,

Thanks for your help. We ended up just using the switch ports in the Motorola for now, rather than a seperate switch, and that worked.

And it turns out it is a CMMMicro, the other CMM2 is somewhere else.


greetings amarriott!
(sorry; copied this from a post i made few minutes ago. thought it might pertain)

the newest cmm upgrade introduces a new set of parameters on the Configurations menu which lets you specify an Uplink port on the cmm.

for some reason the default position seems to be that all ports can talk to one another, which is generally NOT what you would want happening.

further, we had terrible packet collisions after upgrading cmm firmware, and were only able to get to the cmm in the method you described (via an SM) as our cmm is atop a tower (don’t ask).

also, i know it was the cmm firmware as the culprit; we had not updated anything else on the network at that point.

the fix was to either enable all negotiation link speeds in the canopy, in conjunction with enabling auto sensing on each corresponding port on the cmm micro


to hard code values into each side of the link (i.e. 10 MB full duplex at the canopy AP, and also at the cmm end, as opposed to leaving one side open to auto-negotiate.
ask a router genius why that works, and he can probably tell you exactly.

but i DO love it when my customers call out of the blue the next day to tell me their service suddenly got so much better overnight. :roll: