Avaya BCM 2.0 IP Telephony Manual de usuario descargar pdf (Pagina 29)

Engineering guidelines 29

P0911590 Issue 02 Enterprise Edge 2.0 IP Telephony Configuration Guide

Table 6 Computed load of voice traffic per link

Adjusting ping measurements

The Ping statistics are based on round trip measurements, while the QoS metrics in

the Transmission Rating model are one-way. To make the comparison compatible,

the delay and packet error Ping statistics are halved.

Adjustment for processing

The Ping measurements are taken from Ping host to Ping host. The Transmission

Rating QoS metrics are from end user to end user, and include components outside

the intranet. The Ping statistics for delay needs additional adjustments by adding

140 ms to explain the processing and jitter buffer delay of the gateways.

No adjustment are required for error rates.

If the intranet measurement barely meets the round trip QoS objectives, the one-

way QoS is not met in one of the directions of flow. This state can be true when the

flow is on a symmetric route caused by the asymmetric behavior of the data

processing services.

Late packets

Packets that arrive outside of the window allowed by the jitter buffer are discarded.

To determine which Ping samples to ignore, calculate the average one-way delay

based on all the samples. Add 300 ms to that amount. This amount is the maximum

delay. All samples that exceed this one-way delay maximum are considered late and

are removed from the sample. Calculate the percentage of late packets, and add that

percentage to the packet loss statistic.

Measurement procedure

The following procedure is an example of how to get delay and error statistics for a

specific site pair during peak hours.

Links Traffic from

R1-R4 Santa Clara/Richardson

R4-R5 Santa Clara/Richardson

Santa Clara/Tokyo

R5-R6 Santa Clara/Richardson

Richardson/Ottawa

R1-R2 Santa Clara/Ottawa

R1-R4 Santa Clara/Tokyo

R5-R7 Santa Clara/Tokyo

R2-R3 Richardson/Ottawa

R3-R5 Richardson/Ottawa

1 2 ... 24 25 26 27 28 29 30 31 32 33 34 ... 75 76

Sin comentarios

Avaya BCM 2.0 IP Telephony Manual de usuario Pagina 29