The following are the details of the rates and frame sizes applied to the subscriber host queues, the subscriber aggregate rate, and the Vport root scheduler for the scheduling model and when the encap-offset option is enabled in the subscriber profile.
Subscriber Host Queue:
Size = LastMileFrameOverWireEncap + Data
Rate = (48/53)* x (LastMileFrameOverWireEncap + Data)
*Applicable to ATM last-mile only.
Subscriber Aggregate Rate:
Size = LastMileFrameOverWireEncap + Data
Rate = (48/53)* x (LastMileFrameOverWireEncap + Data)
*Applicable to ATM last-mile only.
Vport/Port Scheduler and Weighted Scheduler Group
Size = FrameOverWireEncap + Data
Rate = FrameOverWireEncap + Data
When a frame arrives at the queue, the size is ImmediateEgressEncap+Data. This size is stored as the OfferedFrameSize so that the queue offered stats used in HQoS calculations are correct. See the HQoS-offered statistics as Offered.
This size is then adjusted by removing the ImmediateEgressEncap and adding the LastMileFrameOverWireEncap. This new adjusted frame size, referred as LastMileOfferedFrameSize, is then used for checking compliance of the frame against the queue PIR and CIR bucket sizes and for updating the queue forwarded and dropped stats.
The LastMileOfferedFrameSize value is computed dynamically for each packet serviced by the queue.
A new HQoS stat counter OfferedLastMileAdjusted is maintained for the purpose of calculating the running average frame expansion ratio, which is the ratio of the accumulated OfferedLastMileAdjusted and Offered of each queue:
RunningAverageFrameExpansionRatio = OfferedLastMileAdjusted / Offered
The vport/port port-scheduler hands out its FoW bandwidth in terms of Fair Information Rate (FIR) bandwidth to each subscriber queue. This queue FIR must be converted into LM-FoW format to cap it by the queue PIR (adminPIR) and to make sure the sum of FIRs of all queues of the same subscriber does not exceed the subscriber agg-rate-limit which is also expressed in LM-FoW format. The conversion between these two rates makes use of the cumulative RunningAverageFrameExpansionRatio value.
A queue LM-FoW AdminPIR value is always capped to the value of the local port FoW rate even if the conversion based on the current RunningAverageFrameExpansionRatio value indicates that a higher AdminPIR may be able to fill in the full line rate of the local port.