Proper configurations for using flow control

[whubb]

Hi Chris;

We've been having some weird issues using netonix and Cisco 7300 routers. I was wondering if I can ask you a few questions.

Can you tell me if you use flow control back through your entire network or just from the serving router to an ap on a local segment?

Are you enabling flow control on your air fibers on your links?

At your routers are you allowing send and receive flow control on as desired? or just received.

Our edge routers at the towers are Cisco 7301' but I notice that when you show int it says flow control is unsupported so I don't even know if it will help
to turn on flow control at this point. It's my guess that we need a more updated ios for the router that will support. We can play with hold buffers though.

When you configure to your AP's are you configuring your vlan all the way back to ap or are you just specifying a vlan id on the switch and leaving the ap in bridge with no
vlan tagged to it?

I would love to see a config example of one of your lags on a switch. would it be possible to post your interface config to this post. Maybe delete certain ip data?

We really appreciate the time in answering our questions. We currently own about 16 Netonix switches and love them but it sure seems like some of our bigger sites are having major throughput issues when usage gets over 300mb. I am thinking it's related to lack of lags and flow control.

Would you consider an expanded movie that goes into cisco port configurations and vlan configurations on radios? I know those really are not part of what you support it doing it correctly just makes your switches that much better.

Thank You,

W. Hubbartt

[sirhc]

I will answer more later, tired, but read this and let me know what you think
viewtopic.php?f=30&t=452#p7873

[sirhc]

I have a router at all my towers, Cisco 2941 or 2951

I send my back hauls through the switch setup as a mid-span injector to a router port

I setup a LAG between my tower router and switch to handle local tower radios look further up in this post or watch the 1.5 hour video on YouTube

I do enable flow control on the back hauls BUT:

airFIBERs have a firmware issue with Flow Control so make sure you enable Pause Frame Storm Protection under the Device/Configuration Tab, especially AFX radios until UBNT fixes their firmware. There are many posts on here discussing this just search for them.

Also MIMOSA Flow Control does not work and there has been reports of problems with epmp 2000?

You need to do tests to determine if Flow Control helps or hurts your network topography.

[bdowne01]

Realize I'm replying to a super old thread here, but figured since this pops up when googling "Mimosa Flow Control" a bit more information for future searchers might be helpful.

The company I work for has had issues with Flow Control on Mimosa equipment (as have many others!) and after volleying with Mimosa support for a bit, believe I've stumbled on "why" this is happening.

According to Mimosa, they are using utilization and metrics at the TCP level (i.e. layer 4 sliding window flow control) on the RF link to trigger 802.3x flowcontrol pause frames at the Layer 2/Ethernet level rather than the more correct metric of buffers on the interfaces. In my educated deduction this is flipping the OSI model upside-down and kind of a chicken and egg scenario; i.e. if you can't saturate the wifi link because the buffer are being overrun at the interface, you'll never generate pause frames, and the problem just spins for ever.

Despite my pleas to them that this is a rather bizarre model of implementing 802.3 flow control, and quite unlike every other implementation I've seen, they seem satisfied in their decision in implementing it as they have.

So it seems using flow control on Mimosa gear is a lost cause.