RE: Priority vs Policing

Your understanding is almost correct with a slight confusion on the term
"rate-limit".

When you say "Traffic in this class will ALWAYS be rate limited to 30Kbps
congestion or not, conforming traffic will be transmitted and excess
dropped." - I think you feel that you are getting a guaranteed "minimum"
bandwidth of 30kbps but in actual it doesn't mean that.

"Rate-limit" instead means that if you cross the policed CIR, your traffic
will be dropped. So even if voice traffic is under 30kbits/sec, if there is
congestion, Voice traffic will be dropped.

Priority - you already know what it is..

HTH

Swap
#19084

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
Molomo
Sent: Wednesday, July 29, 2009 4:30 PM
To: ccielab_at_groupstudy.com
Subject: Priority vs Policing

Experts,
Correct me if I'm wrong on the understanding of Priority and Policing in a
policy-map , MQC.

policy-map POLICY_MAP
 class VOICE
   priority 30

Traffic in this class will be gauranteed maximum 30Kbps bandwidth and will
always be send first. When there is no congestion excess traffic will be
forwared but not prioritized and during congestion excess traffic will de
dropped.

policy-map POLICY_MAP
 class VOICE
   police 30000 1000 conform-action transmit exceed-action drop -

Traffic in this class will ALWAYS be rate limited to 30Kbps congestion or
not, conforming traffic will be transmitted and excess dropped.

Now if my understanding is correct why is it that in most
implementations voice traffice is used with priority (LLQ). IMO it will make
more sense to use policing for voice class because ideally you would
always want voice traffic strict policed- congestion or no congestion.

Or am I missing something?

Rgds,
Molomo

Blogs and organic groups at http://www.ccie.net
Received on Wed Jul 29 2009 - 16:56:55 ART