[c-nsp] QoS on an Ethernet Sub-interface

[Justin Shore]

I've got a QoS question for the group; I'm not a QoS buff, at least not 
on the nitty gritty details.  I'm trying to set up some basic QoS on a 
3Mbps PtP Ethernet link.  One side uses a full interface for the link on 
a 2821.  My side uses a 1Q sub-interface on a hardwired GigE port in a 
2821.  I can't apply a matching QoS config due to the sub-interface.  I 
found this guide on how to approach QoS on a Ethernet sub-interface.  It 
specifically states that I have to use a hierarchical QoS policy with 
shaping in the parent before I can use CBWFQ on the sub-int.

http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a0080114326.shtml

The far side uses this:

class-map match-any SIGNAL
  match ip dscp af41
  match ip dscp af31
  match ip dscp cs3
class-map match-any VOICE
  match ip dscp ef
  match ip rtp 16384 16383
!
policy-map WAN_QOS
  class VOICE
   priority percent 35
   set dscp ef
  class SIGNAL
   bandwidth percent 5
   set dscp af31
  class class-default
   fair-queue


I'm looking at applying this:


class-map match-any voip-rtp
  match ip dscp ef
  match ip rtp 16384 16383
!
class-map match-any voip-control
  match ip dscp af41
  match ip dscp af31
  match ip dscp cs3

policy-map voip-child
  class voip-rtp
   priority percent 35
   set dscp ef
  class voip-control
   bandwidth percent 5
   set dscp af31
!
policy-map voip-parent
  class class-default
   shape average ABC
  !
  service-policy voip-child


Overall I think that would work though I'm sure it needs some tweaking. 
  My holdup is the shape average value.  I'm trying to understand what 
it is that I'm shaping with that command.  Should the shape value be the 
max I'm allowing for the VoIP classes referenced by the policy map, the 
max for the link, or some other value that I'm not thinking of?  If it 
is the voip classes will that affect my percentage commands in the child 
classes?  ie, if the shaping was set at 1Mbps would the 35% in the child 
come out at 350k?

Thanks
  Justin