VoIP QOS best practices

Mon Feb 10 19:01:39 UTC 2003

On Mon, 10 Feb 2003, Ray Burkholder wrote:

> 
> QoS isn't necessarily about throwing packets away.  It is more like
> making voice packets 'go to the head of the line'.  Of course, if you
> have saturation, some packets will get dropped, but at least the voice
> packets won't get dropped since they were prioritized higher.

Thats what I meant too...

To qualify further on where it needs to be deployed, its required on whatever 
the slowest link in the typical path to "the Internet". What I mean is that if 
you download your email you will utilise the whole bandwidth of the slowest link 
in the chain, this may be a dialup modem but more likely in the office to be 
your T1, you dont want this full utilisation of the link (which will occur in 
small bursts of a few seconds, dont forget with voice we are interested in per 
second traffic volumes not 5 minute averages!) to affect the jitter you need to 
implement priorities at this point.

Steve

> 
> Ray Burkholder
> 
> 
> > -----Original Message-----
> > From: Bill Woodcock [mailto:woody at pch.net] 
> > Sent: February 10, 2003 14:05
> > To: Charles Youse
> > Cc: nanog at nanog.org
> > Subject: RE: VoIP QOS best practices
> > 
> > 
> > 
> >     > That doesn't seem to make a lot of sense - is it that 
> > QoS doesn't work as advertised?
> > 
> > That's generally true as well.  But why would you need it?  What's the
> > advantage to be gained in using QoS to throw away packets, when the
> > packets don't need to be thrown away?
> > 
> >     > As someone who is looking to deploy VoIP in the near 
> > future this is of particular interest.
> > 
> > Go ahead and deploy it.  It's easy and works well.  It 
> > certainly doesn't
> > need anything like QoS to make it work.
> > 
> >                                 -Bill
> > 
> > 
> > 
> 