Bandwidth percentage for nested policy maps

[rtjensen4]

Hey All,

I'm trying wrap my head around bandwidth guarantee for nested maps. I tried adding a new class to two of my policy-maps today, and got this error:

3945E-1(config-pmap-c)#bandwidth 3000

Insufficient bandwidth 3000 kbps for the bandwidth guarantee

I'm not sure how it knows that with the nested maps and how it's computed. I have a 100mb WAN connectin going to 19 branches.

I have a class-map that identifies traffic to the individual branch and within that class, a policy-map is applied to prioritize voice over video etc.

Here's the QoS setup:

class-map Branch1-Policy

match access-group branch-1-acl

*

*

*

class-map Branch-19-Policy

match access-group branch-19-acl

!

!

policy-map Global-branch

class class-default

  shape average 100000000

   service-policy Branches-NLAN

!

!

policy-map Branches-NLAN

class Branch-1 Policy

  shape average 10000000

   service-policy Traffic-10calls

*

*

class Branch-19 Policy

  shape average 3000000

   service-policy Traffic-6calls

!

!

policy-map Traffic-10calls

class VoIP-Control

  bandwidth 16

  set dscp cs3

class VoIP-Voice

  priority 880

  set dscp ef

class Symitar

  bandwidth 64

  set dscp af21

class Video-Conf

  set dscp af41

  bandwidth 1500

class class-default

  fair-queue

  queue-limit 128 packets

policy-map Traffic-6calls

class VoIP-Control

  bandwidth 16

  set dscp cs3

class VoIP-Voice

  priority 512

  set dscp ef

class Symitar

  bandwidth 64

  set dscp af21

class Video-Conf

  set dscp af41

  bandwidth 1500

class class-default

  fair-queue

  queue-limit 128 packets

I was adding the Video-Conf class to both Traffic-6calls and Traffic-10calls when I got the above error.  How would that percentage be calculated? I know by default i can only reserve up to 75% of interface bandwidth.

The platform is 3945E running 15.1(3)

Can someone clarify for me? Thanks!

[Joseph W. Doherty]

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Posting

It's likely your version of IOS will show what it believes each class's bandwidth allocation is.  Of interest is your class-default, where you haven't defined any bandwidth.  (NB: the 75% rule, I think to which you refer, is pre-HQF.)  Don't recall what your IOS version will allocate for class-default, but assume whatever it is, it, along with all your explicitly (non-%) class allocation is exceeding parent shaper's bandwidth allocation.