[c-nsp] Shaping not working as expected

[John Lange]

I'm trying to keep this short so hopefully I don't leave out some
critical detail.

I have a hierarchical policy-map applied to a 100 mb interface which
only has 15mb available from the provider so the parent link needs to
be shaped to 15mb.

The classes need as follows: VOIP needs 1mb priority, OTHER needs a
guarantee of 3mb, and DORMS has to be restricted to 7.5mb.

So we have this:

! child policy
policy-map WAN_Egress
 class VOIP_Outbound
  priority 1024
 class OTHER
  bandwidth 3072
 class DORMS
  shape average 7500000

! parent policy
policy-map WAN_Egress_shaping
 class SHAPE
  shape average 15000000
  service-policy WAN_Egress

interface FastEthernet0/0/0
 description "15Mb LINK TO PROVIDER"
 bandwidth 15000
 service-policy output WAN_Egress_shaping

---

But somehow, "show policy-map interface" shows me that DORMS is
exceeding its limit and shaping is not active even though the packets
are matching. How can that be possible?

Here is the output:

Class-map: DORMS (match-any)
  1652936 packets, 1239925276 bytes
  5 minute offered rate 8455000 bps, drop rate 0 bps
  Match: access-group name DORMS-SRC
    1652936 packets, 1239925276 bytes
    5 minute rate 8455000 bps
  Traffic Shaping
       Target/Average   Byte   Sustain   Excess    Interval  Increment
         Rate           Limit  bits/int  bits/int  (ms)      (bytes)
      7500000/7500000   45000  180000    180000    24        22500

    Adapt  Queue     Packets   Bytes     Packets   Bytes     Shaping
    Active Depth                         Delayed   Delayed   Active
    -      0         0         0         0         0         no

Cisco IOS Software, 2800 Software (C2800NM-ADVENTERPRISEK9-M), Version
12.4(15)T10, RELEASE SOFTWARE (fc3)

--
John Lange
www.johnlange.ca