# Prioritize empty ack packets with ipfw?



## x32smooth (May 17, 2011)

Hello,

I read about enhancing the overall responsiveness and download-speed when a concurrent upload is running using this approach of priorizing empty ack packets. Since I'm on a pretty slow adsl-connction (384/64 kbit/s) I hope this could help to reduce some of the waiting time I have when doing simple things like websurfing.
I didn't find a manual for doing this using ipfw. Maybe someone here is willing to help 

My configuration is: 
* FreeBSD 8.1 as DSL-router 
* interface to my lan is: ue0 (192.168.10.1)
* interface to dsl-modem: fxp0

I'm using ppp to connect to the internet and its built-in nat feature to share this connection (btw: I read that ipfw has a nat feature as well, would there be a reason to switch to this one?)

Many thanks in advance.


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## ecazamir (May 17, 2011)

AFAIK, FreeBSD does not have any mechanism to prioritize packets managed directly with ipfw. FreeBSD's dummynet is able to add delays, loss-rate, maximum-bandwith and weights to ip flows/streams, but not priorities.

If you need prioritization, then you should try using 'pf'. pf is 'priority' aware. This page should help you implementing it.


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## bbzz (May 17, 2011)

x32smooth said:
			
		

> Hello,
> 
> I read about enhancing the overall responsiveness and download-speed when a concurrent upload is running using this approach of priorizing empty ack packets. Since I'm on a pretty slow adsl-connction (384/64 kbit/s) I hope this could help to reduce some of the waiting time I have when doing simple things like websurfing.
> I didn't find a manual for doing this using ipfw. Maybe someone here is willing to help
> ...



Just wanted to mention that this would only work if your upload connection is saturated (which is when software queuing kicks in), that is, you do some heavy uploading.


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## x32smooth (May 17, 2011)

Thanks to both of you. So i have to switch to pf. Ok 'ill try 

bbzz: 'heavy' is relative with such a limited linespeed


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