[c-nsp] QoS support on Catalyst 6503

[Tim Stevenson]

QoS capability is based on the PFC & modules, not the chassis.

Policing capabilities are in the PFC, and have not really changed that much 
(aside from output policing on L3/VLAN basis, policing based on L2 length 
not L3 length, and multiple flow mask microflow policing, in PFC3). 
Admittedly, it is more of an art than a science to picking the right values 
to achieve the desired rate based on your traffic.

The scheduling, on the other hand, is dictated by the capabilities of the 
module ASICs.

Tim


At 03:30 AM 9/30/2004, cisco-nsp-request at puck.nether.net maundered:
>Message: 7
>Date: Thu, 30 Sep 2004 10:40:28 +0200
>From: sthaug at nethelp.no
>Subject: Re: [c-nsp] QoS support on Catalyst 6503
>To: ipmonger at delamancha.org
>Cc: cisco-nsp at puck.nether.net
>Message-ID: <99693.1096533628 at bizet.nethelp.no>
>Content-Type: Text/Plain; charset=us-ascii
>
> >    I have some basic questions regarding QoS implementation on a Cisco
> > 6503.
> >
> >    My experience with policing on the 6509 from the 1999-2002 period was
> > that the policing wasn't as strict as what you'd expect from CAR
> > (typically a few extra Mbps of traffic "leaked" througH).  Cisco
> > informed me that this was due to the way that the equipment was
> > implemented -- i.e. it didn't have enough guts to police at a faster
> > rate, so there was a basic limit to what it could do.
> >
> >    I have no experience with the 6503 - is it a different implementation
> > than the 6509?  Does it's QoS suck as much as the 6509s did then?  Is
> > it better now?  What about prioritization and queueing?
>
>As far as I know, the 6503 behaves exactly the same as the 6509 in
>this respect, for the simple reason that the same components are
>used. As far as I recall the PFC is the component does the policing.
>The Sup720 (PFC3/PFC3B etc) is more capable that the Sup2/PFC2 here,
>for instance by supporting output policing (which the Sup2/PFC2 does
>not).
>
>Steinar Haug, Nethelp consulting, sthaug at nethelp.no



Tim Stevenson, tstevens at cisco.com
Routing & Switching CCIE #5561
Technical Marketing Engineer, Catalyst 6500
Cisco Systems, http://www.cisco.com
IP Phone: 408-526-6759
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