Policing vs shaping

Hi. Im wondering if its logical to configure policing and shaping at the same time to the same class and apply to an egress interface outwards?


policy-map RATE_LIMIT
class BAND256
bandwidth 256
random-detect
police cir 256000 bc 300000 conform-action transmit exceed-action drop
shape peak 256000

What are you trying to accomplish with this config?

My router doesnt have the 'rate limit' command, and i use it to supply my clients with different bandwidth requirements. like client A wants 256mb, client B wants 512mb......
I wanted an alternative to the rate limit command to limit bandwidth to my clients to the exact amount they are paying for.
I wasnt sure whether this will work!

I dont believe the shape peak is going to be doing much since policing and shaping are assigned to the same class.

What is the physical line rate of the port you want to attach to the service policy?

Your config on the policer has a Bc commit interval that is much bigger than the CIR. Not sure thats what you want, typically the Bc inteval accounts for .4% to 12.5% of CIR. The CIR in given in bps and the Bc is given in bytes. The shape peak command is also Bc + Bc at every time constant and I do not believe the shaper would be used in the current config.

A heirarichal approach may be a better option. Shape all the classes in a parent class and perform policing in each child class.

This is my new config. I have 4 ingress interfaces for clients and 1 egress to the ISP which has a 2Mbps link.

policy-map RATE_LIMIT
class BAND256
bandwidth 256
random-detect
police cir 2048000 bc 25600 conform-action transmit exceed-action drop
shape average 2048000

class BAND512
bandwidth 512
random-detect
police cir 4096000 bc 64000 conform-action transmit exceed-action drop
shape average 4096000

class RTP
priority 256
class BAND128
bandwidth 128
random-detect
police cir 1024000 bc 16000 conform-action transmit exceed-action drop
shape average 1024000

class class-default
fair-queue

Losh,


Does this configuration for work you ? I have found many issues with QoS, especially when you try to perform egress rate limiting on ATM WAN interfaces e.g ADSL.