Dear all,
http://www.cisco.com/en/US/docs/ios/qos/configuration/guide/qos_frhqf_support.html
Nested Policy and Reference Bandwidth for Child-Policy
In HQF when you configure a nested policy with a child queueing policy under a parent shaping class, the reference bandwidth for the child queueing policy is taken from the following: minimum (parent shaper rate, parent class's implicit/explicit bandwidth guarantee). When you do not define bandwidth for the parent class, the interface bandwidth divides equally among all parent classes as the implicit bandwidth guarantee.
The example below shows a nested policy applied on a serial interface of 1536 Kbps. The 1536 Kbps is equally shared, as the implicit bandwidth, among parent classes parent-c1 and class-default. For the parent class, the shaping rate of 1200 Kbps is the maximum, while the implicit guarantee of 768 Kbps is the minimum.
What will the details of the implicit guarantee be?
(Example)
768Kbps = 1536Kbps÷2