Mitel MiVOICE BUSINESS, Engineering Manualline

Page: 131 / 381

Performance
117
SYSTEM PERFORMANCE INDEX
In order to calculate the performance limits of a system, different weighting values are assigned
to various types of calls. Typically an ONS-to-ONS call is considered to have a loading factor
of 1.0, and an IP phone-to-IP phone, a loading factor of 3.2. Other call types (ONS to PSTN
trunk, IP phone to IP trunk, etc.) are assigned different values based on actual performance
tests. Based on the expected calls per hour (CPH) of all of the user ports on the system, a
system performance index (PI) can be calculated that indicates the processor loading at those
traffic rates. The system PI is used as an indication of how much traffic the 3300 ICP can handle
at any one time.
Check the actual performance with the System Engineering Tool, available through
Sales/System Engineering
. The larger systems contain multiple processors, so the performance
index (PI) value can be used directly in calculating the load. In smaller systems (AX, CX and
base MXe), the single processor must handle multiple tasks, so the available PI is reduced.
This additional load is taken into account automatically in the System Engineering Tool.
In addition to traffic, many other factors affect system PI. For example, a large number of voice
mail ports can significantly increase the system PI because streaming data to the hard disk is
a CPU-intensive operation. Similarly, call monitors (features, not voice) used for ACD, Hot Desk,
and several external applications, along with SMDR logging, can add processor load. These
are all taken into account automatically in the System Engineering Tool.
PERFORMANCE LIMITATIONS
Figure 11 shows the performance limitations for a 1400 line LX or MXe controller; Figure 12
shows the performance limitations for a 1400 line MXe Server. The maximum calls per hour
are for Poisson distributed traffic. The number of registered sets is the number that is actually
connected to the controller, including those that might be connected because of failover in a
resilient configuration. The limits shown in these figures are determined by performance only;
there may be other limits (for example, licenses) which restrict operation to lower traffic or
numbers. Use these graphs in conjunction with the System Engineering Tool to determine the
appropriate configuration. Note that for larger systems, typically with more than 500 users
attached, the maximum performance may only be obtained by using the ICP as a group
Table 38: Factors affecting Performance Index
SYSTEM FEATURE PI IMPACT
SMDR reporting 10%
MiTAI monitoring 10%
MiTAI call control (MiCollab Client and applications) 40%
Voice Mail up to 80%
Compression (note) up to 50%
Note: Compression impact applies to MXe base, AX, and CX (single processor) systems only.
Note: The use of large numbers of MiCollab Client and MiCollab Client Softphones will
impact system performance because of the use of MiTAI call control and monitoring.
Please refer to “MiCollab Client and MiCollab Client Softphone” on page 73 for details.