Installation guide

Extension Monitoring Limitations Planning and System Design
2
ShoreTel 14.2 Planning and Installation Guide 39
Extension Monitoring Limitations
That there is a limit to the number of extensions that can be monitored, whether from a ShoreTel IP
Phone -BB24 device or from a ShoreTel IP Phone multiline phone. This limitation is dependent on two
factors:
 Update rate (every call causes one or more monitoring phones to be updated.
 Whether the monitoring phones are spread across one or more switches.
ShoreTel Voice Switches support an update rate of 1 per second. This limit is independent of whether
the monitored extensions are on the same switch or a different switch. If the monitored extensions are
on a different switch, then IPDS is involved.
ShoreTel Voice Switch Feature Capacity
The ShoreTel voice switch is designed to handle the maximum load for the services it provides. Some
features place a higher real-time load on the ShoreTel voice switch processor than others, and the use
of these features must be carefully planned to take into account the impact on the processing power of
a switch to handle call control signaling messages.
Table 11 offers some general guidelines for the number of extensions and group members for several
commonly used features. Keep in mind that in addition to observing these limitations, you must stay
below the real-time requirements of the switch itself.
IP phones
Ringing a single user's IP phone generates only one set of call control messages. However, as the call
rate increases, the load on the processor also increases. Note that the call rate is the driving factor of
load and not the length of a call. For instance, sixty calls placed over one hour, with each call lasting
one minute, is a much higher load on the processor than a single call lasting one hour.
Table 11: Feature Capacity
Hunt Group
Bridged Call
Appearance
Pickup Group IP Phones
Extension 8 24 16 120
Members/
extensions
16 32 – phones
monitoring the
same extension
24 N/A
Stack size/
extensions
24 24 N/A 24
Total members on
all extensions
16 N/A 80 N/A