[Firehol-support] rate values in FireQOS with overhead or without?

Phineas Gage phineas919 at gmail.com
Mon May 5 18:40:24 CEST 2014


Ok, that makes sense.

I’m surprised by the amount of overhead in ADSL / PPPoE / LLC. My VOIP phone sends exactly 50 UDP packets / second of length 32, as reported by tcpdump. That’s a data rate of 24kbps, taking the 28 byte UDP header into account. But “fireqos status” shows a rate of 66kbps. After some research, it looks like each VOIP packet breaks down like this:

  32 bytes data
  28 bytes UDP+IPv4 header
  96 bytes MAC, PPP, PPPoE, ATM, AAL5 (http://www.technicolorbroadbandpartner.com/getfile.php?id=525‎)

No wonder my previous custom QoS script never worked for VOIP very well, the overheads are very high and I never took them into account. FireQOS is really useful for this.

Thanks for the response.

On May 5, 2014, at 9:41 AM, Tsaousis, Costa <costa at tsaousis.gr> wrote:

> Hi,
> 
> the rates should be the final, with overheads.
> If you compare tc values to actual network values you will se the difference. The network interface reports smaller numbers.
> 
> Costa
> 
> 
> 
> On Sun, May 4, 2014 at 5:26 PM, Phineas Gage <phineas919 at gmail.com> wrote:
> When entering rates for a class in FireQOS, should they be with packet overheads or without?
> 
> When a VOIP call is active in my environment (codec unknown) I see a rate of 66 show up in the VOIP class, pretty consistently. What I’m trying to figure out is if this is the rate I should have configured in my fireqos.conf (maybe with some padding), or if it should be something smaller, without overhead.
> 
> _______________________________________________
> Firehol-support mailing list
> Firehol-support at lists.firehol.org
> http://lists.firehol.org/mailman/listinfo/firehol-support
> 

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