[c-nsp] QoS with Voice and Video

[Higham, Josh]

> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of 
> Mikael Abrahamsson
> 
> On Wed, 28 Jan 2009, Pelle wrote:
> 
> > That depends on the type of video, is it video conferencing 
> (IP/VC) or 
> > streaming video (IP/TV)? IP/VC are interactive video, and 
> have more or 
> > less the same requirements on latency, jitter and loss as 
> VoIP. IP/TV on 
> > the other hand can handle more latency, jitter and loss.
> 
> I am of another opinion. I don't believe in putting bursty 
> traffic into 
> LLQ. LLQ should be used for deterministic traffic (ie 20 pps VOIP or 
> equivalent broadcast video with basically fixed pps and bw/s).
> 
> Some platforms drop packets when it's over the prio limit and 
> to protect 
> from starvation of other classes I recommend putting a policer on the 
> priority class anyway.

In this case I am talking about video conferencing, and it will both be
policed and have CAC in place.  So while it does have variable bandwidth
(depending on compression ratios), I will be accounting for maximum
utilization.  Given that, it appears to be viable either with both as
priority, or video as non-priority bandwidth reservation.

It sounds like it's only an issue if you either don't police it (so
priority could burst to full link utilization), or if video can burst up
to and above the police rate (which would then risk dropping VOIP
priority traffic).

Thanks for the help,
Josh