Network Router User Manual

Release 11.0 Release Notes and User Guide Supplement
Issue 1, March 2011 Page 28
Table 7: Notes first discussed with Release 10.3.1
Products
Affected
Description
Discussion and Recommendations
PMP 430
used with
Prizm or
BAM
PMP 430 SM
MIR configured
by Prizm to
greater than max
sustained MIR
data rate (12257)
If the Configuration Source on a PMP 430 AP’s Configuration > General
tab is set to Authentication Server or Authentication Server + SM,
SMs will receive their MIR settings from Prizm (or BAM). The resulting SM
MIR may be greater than the keyed throughput of the SM. For context, the
PMP 430 SM is available keyed to have a maximum throughput of 4, 10,
20 or 40 Mbps.
If the SM receives a MIR setting from Prizm that is greater than the keyed
bandwidth, the SM will cap the MIR using this formula:
(desired uplink MIR * SM aggregate capped rate) / desired aggregate rate
(desired downlink MIR * SM aggregate capped rate) / desired aggregate rate
Note: Desired aggregate rate is the sum of the desired uplink rate and desired
downlink rate
For example, if a PMP 430 4 Mbps SM with a max MIR cap of 4000
receives a MIR setting from Prizm that is greater than 4000 kbps, it will
cap the downlink MIR and the uplink MIR to equal a max of 4000 kbps.
Below is an example with Prizm settings of 10000 kbps uplink MIR and
7000 downlink MIR sent to a 4 Mbps SM that is capped at 4000 kbps max
MIR:
Uplink calculation: (10000 * 4000) / (7000 + 10000) = 2352 kbps
Downlink calculation: (7000 *4000) / (7000 + 10000) = 1648 kbps
Thus the Uplink MIR of 2352 + Downlink MIR of 1648 = 4000 kbps
In this example, the PMP 430 AP sessions page will display a SM uplink
and downlink MIR SMCAP as shown below.
For reference, the max SM MIR in kbps for each SM type is:
4 Mbps SM = 4000
10 Mbps SM = 10000
20 Mbps SM = 20000
40 Mbps SM = 65535 (displays Unlimited in the Home > General Status tab)