QoS Config on WAN Router

[MICHAEL BURNS]

I am working on implementing QoS on our WAN router and want to run this by the community to see if I am doing what I think I am doing. Here are the facts.

1. Traffic is being classified and marked by Riverbed Steelhead
2. WAN link is a 622 Mb OC-12
3. I want to guarantee 10% of link for EF traffic
4. I have changed maximum-reserved-bandwidth to 100%
5. I have divided up the other 4 classes as follows:
   NORMAL (Includes all RFC 1918 as source and destination) 50%
   INTERACTIVE 10%
   BUSINESS CRITIAL 20%
   LOW_PRIORITY 10%

Here's my proposed config:

class-map match-any REALTIME
  match dscp ef
class-map match-any INTERACTIVE
  match dscp af41
class-map match-any BUSINESS_CRITICAL
  match dscp af31
class-map match-any NORMAL
  match dscp af21
class-map match-any LOW_PRIORITY
  match dscp af11
!
policy-map EGRESS
 class NORMAL
   bandwidth percent 50
 class INTERACTIVE
   bandwidth percent 10
 class BUSINESS_CRITICAL
   bandwidth percent 20
 class LOW_PRIORITY
   bandwidth percent 10
!
policy-map qos-voice
  class REALTIME
    priority 62200
class class-default
  fair-queue
    random-detect dscp-based
 service-policy EGRESS
! 

Any suggestions? Any possible issues?

[Philip D'Ath]

Why not just create the one policy?

policy-map EGRESS
 class REALTIME
    priority 62200
 class NORMAL
   bandwidth percent 50
 class INTERACTIVE
   bandwidth percent 10
 class BUSINESS_CRITICAL
   bandwidth percent 20
 class LOW_PRIORITY
   bandwidth percent 10

[MICHAEL BURNS]

My company has a strict policy against efficient use of CLI : )

Thanks, Phil.  That was a good catch!

[Philip D'Ath]

Oh, you work for a Microsoft shop.  :-)

[Joseph W. Doherty]

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Posting

Philip already noted you don't need a child policy.

With a combined single policy, your normal class could use the default class.

I recommend you avoid using RED, as it's actually much more complicated to "get right" than the manual or most QoS texts explain.

If you platform supports it, you might want to enable FQ on all your non-LLQ classes.

BTW, when using FQ, often you don't need to break out different non-LLQ classes, except when you have a critical need to guarantee bandwidth or you're trying to prioritize traffic.  For example you might give your Interactive class 50%, not that you expect it will use that bandwidth, but to insure it gets more attention from the scheduler for packet forwarding.  (NB: with higher speed links, like your OC-12, scheduling priority isn't as important.)

Your platform might also support a percentage for LLQ.