[nsp] Stupid QoS Tricks

Christopher J. Wolff chris at bblabs.com
Tue Nov 18 01:03:02 EST 2003

Is the following snippet also an option?  Is it safe to ass-ume that packets
with ipprec 5 can have the entire 4 meg if desired?  Thanks!

class-map match-any ipprec5
 match ip precedence 5

policy-map voice_traffic_w4megabit_data
 class ipprec5
  shape average percent 100
 class 4megabit
  police 4000000 6000000 12000000 conform-action transmit exceed-action drop

interface FastEthernet0/1
 service policy input voice_traffic_w4megabit_data
 service policy output voice_traffic_w4megabit_data

-----Original Message-----
From: Luan Nguyen [mailto:lmnguyen at cox.net] 
Sent: Monday, November 17, 2003 10:11 PM
To: Christopher J. Wolff; cisco-nsp at puck.nether.net
Subject: Re: [nsp] Stupid QoS Tricks

Maybe you should try to use Class Based Weighted Fair Queuing.  I think that
is another method of prioritizing queuing that apply to VoIP over Frame
Relay.  In this method you define classes of traffics and assign them an
absolute bandwidth that they have available during periods of congestion.
The voice queue will act as a priority queue and be serviced first.  

class-map X
  match input-interface LAN
class-map class-default
  match any 
class-map voice
  match access-group 101
policy-map WAN
  class voice
     priority Z - Guarantee bandwidth for voice class Any packet with IP
Precedence = 5 gets assigned to a class that will get a minimum of Z kbps
  class data
     bandwidth 4000
interface WAN
 bandwidth DS3
 no ip directed-broadcast
 service-policy output WAN
access-list 101 permit ip any any precedence critical

A link on how to configure CBWFQ:

Hope that help a little bit.  I am not very good at this.


> From: "Christopher J. Wolff" <chris at bblabs.com>
> Date: 2003/11/17 Mon PM 06:22:46 EST
> To: <cisco-nsp at puck.nether.net>
> Subject: [nsp] Stupid QoS Tricks
> Here's a scenario I could use some guidance on.  I've read quite a bit on
> Cisco's site but didn't find a direct correlation.  So here goes.
> Customer has a DS3, of which 4 meg is provisioned for data.  Now customer
> wants to add VOIP services.  
> Assumptions:
> - The customers' 4 meg is rate-limited by service policies / policing.
> - The 4 meg circuit is generally saturated since it is a wi-fi
> environment.
> - There is no VLAN capability on the customer LAN.
> My initial thought was to apply an ip rtp reserve to the customer
> which I did.  However it seems like there should be a better method to
> guarantee voice traffic while maintaining the customers' data 'partition'.
> Thank you in advance for your advice.
> Regards,
> Christopher J. Wolff, VP, CIO
> Broadband Laboratories
> http://www.bblabs.com
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