Cisco MWR 2941 Command Reference Manual page 703

Cisco MWR 2941 Router Command Reference, Release 15.0(1)MR
Calculate the minimum peak, average, and burst values for the number of voice calls as follows:
Peak Value
Peak value = (2 x the maximum number of calls) x 16K = _______________
Average Value
Calculate according to the maximum number of calls that the PVC will carry times the bandwidth per
call. The following formulas give you the average rate in kbps:
•
•
If voice activity detection (VAD) is enabled, bandwidth usage is reduced by as much as 12 percent with
the maximum number of calls in progress. With fewer calls in progress, bandwidth savings are less.
Burst Value
Set the burst size as large as possible, and never less than the minimum burst size. Guidelines are as
follows:
•
•
When you configure data PVCs that will be traffic shaped with voice PVCs, use AAL5snap
encapsulation and calculate the overhead as 1.13 times the voice rate.
Examples
The following example configures the traffic-shaping rate for ATM PVC 20. Peak, average, and burst
rates are calculated based on a maximum of 20 calls on the PVC.
Router# configure terminal
Router(config)# interface atm0/0
Router(config-if)# pvc 20
Router(config-if-atm-vc)# encapsulation aal5mux voice
Router(config-if-atm-vc)# vbr-rt 640 320 80
Related Commands
OL-23890-01
For VoIP:
G.711 with 40- or 80-byte sample size:
–
Average value = max calls x 128K = _______________
– G.726 with 40-byte sample size:
Average value = max calls x 85K = _______________
– G.729a with 10-byte sample size:
Average value = max calls x 85K = _______________
For VoATM adaptation layer 2 (VoAAL2):
G.711 with 40-byte sample size:
–
Average value = max calls x 85K = _______________
G.726 with 40-byte sample size:
–
Average value = max calls x 43K = _______________
– G.729a with 10-byte sample size:
Average value = max calls x 43K = _______________
Minimum burst size = 4 x number of voice calls = _______________
Maximum burst size = maximum allowed by the carrier = _______________
Cisco MWR 2941 Router Command Reference, Release 15.0(1)MR
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