From: ccie2be (ccie2be@nyc.rr.com)
Date: Mon Nov 22 2004 - 10:58:27 GMT-3
Well, I think I found the answer to my questions regarding CAR vs Police
using MQC.
With the new features now available, there is NO functionality in CAR that
isn't available with MQC.
See this link:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t13/ft3level.htm
As this link shows, it's now possible to nest police commands with MQC.
And, it's also possible to match traffic based on dlci, so therefore a
policy can be applied to the traffic of one particular dlci.
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t13/ftpcdlci.htm
I assume that when matching traffic based on dlci, whether the dlci matched
is the incoming or outgoing depends on whether the service-policy is applied
to outgoing or incoming traffic, but I can't confirm that until I get some
rack time.
Any thought?
Tim
----- Original Message -----
From: "ccie2be" <ccie2be@nyc.rr.com>
To: "Bob Sinclair" <bsin@cox.net>; "Anas Tarsha" <ra3i@yahoo.com>; "Group
Study" <ccielab@groupstudy.com>
Sent: Sunday, November 21, 2004 5:35 PM
Subject: Re: CAR vs Police
> Hi Bob,
>
> As I going over all the old GS posts on policing, I came this one
comparing
> CAR and Police.
>
> According to the DQoS by Odem, one of the differences is that with CAR you
> can configure nested rate-limit commands but not with MQC. Since there's
> been alot of new features added to MQC, I wonder if that still holds true.
>
> For example, according to Odem, you couldn't enable MQC on a per dlci
basis,
> but since now you can match on dlci, you can.
>
> So, I wonder if a config like this would fly
>
> policy-map VOICE
> class VOICE
> police 128000
>
> policy-map ALL-TRAFFIC
> class class-default
> police 256000
> service-policy VOICE
>
> Any thoughts?
>
> Thanks, Tim
>
> ----- Original Message -----
> From: "Bob Sinclair" <bsin@cox.net>
> To: "Anas Tarsha" <ra3i@yahoo.com>;"Group Study" <ccielab@groupstudy.com>
> Sent: Saturday, December 06, 2003 9:51 PM
> Subject: Re: CAR vs Police
>
>
> > Anas,
> >
> > I would agree that Cisco could do a better job of explaining the
policing
> > mechanism in the MQC, but I think I would disagree that it permits
> buffering
> > during congestion. There are Bc and Be parameters, but according to the
> > documentation this does not buffer packets to shape the traffic. The
best
> > explanation I have found is at the link below, which says that the
policer
> > does not buffer, but "drops packets less aggressively" during
congestion.
> > Could you check it out and see what you think of it?
> >
> >
>
http://www.cisco.com/en/US/partner/tech/tk543/tk545/technologies_q_and_a_item09186a00800cdfab.shtml#Q24
> >
> > Thanks!
> >
> > -Bob Sinclair
> > CCIE #10427, CISSP, MCSE
> >
> >
> > bsinclair@netmasterclass.net
> > ----- Original Message -----
> > From: "Anas Tarsha" <ra3i@yahoo.com>
> > To: "Bob Sinclair" <bsin@cox.net>; "ccie2be" <ccie2be@nyc.rr.com>;
"Group
> > Study" <ccielab@groupstudy.com>
> > Sent: Saturday, December 06, 2003 9:07 PM
> > Subject: Re: CAR vs Police
> >
> >
> > > Also theoretically there is a major difference between
> > > CAR and policing, a difference which Cisco hardly
> > > explains it well in my opinion. CAR is a rate-limit
> > > mechanism to limit the input or output transmission
> > > rate on an interface or subinterface based on a
> > > configured value. All the exceeding traffic is dropped
> > > in case the exceeding action is dropping. Policing is
> > > more like a shaping mechanism. As the name implies,
> > > shaping does not drop packets in case of congestion,
> > > it buffers them. You will see delay but no data loss.
> > > So this is the major difference, CAR does not buffer.
> > >
> > > Anas
>
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