EPMP 2000 and Mikrotik Pause Frames

I have an epmp 2000 plugged directly into a Mikrotik Powerbox Pro, and with no traffic going through the radio it incraments pause frames at the rate of ~500 per second.  I noticed if i disable STP on the bridge, this decreases to ~200 per second.  

When loading the GUI on the radio, this increases to >1000 per second.  No other traffic is happening on the router or the radio. 

I'm almost worried to even attempt to put this on a live tower with customers and traffic.

I have read through numerous posts about epmp 2000's and pause frames on Mikrotik routers and have seen no real solution mentioned besides flow control (which really isn't a solution, and causes issues for VOIP, etc).  Some people also suggest upgrading equipment to prevent bottlenecks but I'm seeing pause frames with no traffic going through undeployed brand new equipment hooked up in the lab. I also see that some people get pause frames and some people don't.

Is there anything else I can do or try?  Did anyone else have this issue, and figured out a way around it? We have many powerbox pro's on our network with everything from UBNT, Mikrotik, Canopy, Mimosa, and even epmp1000, but I'm only seeing this at the moment with the 2000's.

I would think there would be a response to this, given how common Mikrotik users are.  Using a PowerBox would be a great solution for small pops that are running fiber and power up the tower. 

Can we please get a response from Cambiuim engineering support on this issue?


Ditto - I have a few towers were I'm waiting to deploy ePMP2000's and my plan was for PowerBox Pro... and I've been hesitant to climb and deploy with these posts.  I don't really know enough about MikroTik to know how to diagnose this. :( 


I noticed your post and I checked on some MikroTik routers with ePMP 2000 attached and you're right: I can see very big numbers on Rx Pause with an increment of more than ~20000/sec.

People from Cambium, why there is this issue?
Tx flow control and Rx flow control are disabled on interfaces...

I can see lots of Rx Pause also on Force 200 ports. 

0 Rx Pause on all other devices (Ubiquiti, MikroTik, Mimosa...)


I also went to check this on my routers and same thing !

Only on epmp2000 not epmp1000!

Hi all,

We are looking into it right now.

I will revert to you with updates soon.

Thank you.

1 Like

I get these on almost all of my Airfiber 5x's...

Ok AirFibers I have 0 RX Pause… only on Cambium

Flow Control is enabled on ePMP radios by default.

But it doesn't explain high number of RX Pauses on the weakly loaded link.

We have reproduced issue in the lab, but number of pauses is significantly lower.

Will revert to you with updates shortly.

Thnak you.

Is it possible to disable flow control?

If it helps any we also see this on EPMP 2000 using Netonix switches. 

Epmp 1000 we see hardly any pause frames.


I am new here and running a hotel website.



kerela tour packages for couple

Forgot to add that it is related to amount of traffic going across it from what I sen see on our live network.

We even have a force 200 plugged into the same switch using it as a PTP to a customer. When we run a heavy load over the link the RX pause frames jump drastically. When we stop the speed test the RX pause frames stop for like 5 seconds then start up but at a lower rate.

Any updates on this issue?

I have tested this with EPMP2000 just lying on the test bench in lab, connected to netonix switch and also get continuous pause frame count. Is there any way to disable flow control on the Cambium units?

Any updates on this yet?

Also experiencing it with ePMP1000 with GPS Sync, on firmware 3.5.1 as well as 3.5.2.

These are connecting via provided 30v Gigabit POE and negotiating @ 1Gb Full Duplex

Tx and Rx flow control is off by default on router (Mikrotik RB1100x4) - Funny thing is were getting this on some devices and others are perfectly fine on the same tower, same setup, same router etc.

Any further updates on this?

We also are having the same issue, waiting to hear more about possible causes/fixes if needed.

@Fedor wrote:

Hi all,

We are looking into it right now.

I will revert to you with updates soon.

Thank you.

Any updates yet?

I wanted to chime in here. I have a 5700 and a 2400 EPMP 1000AP attached to a RB2011UiAS-2HnD. One at 1gb other at 100mb. I am getting zero pause frames. Auto-negotiate and both flow controls OFF. I am using a POE-Texas multi-POE injector for powering both.