Information Technology Reference
In-Depth Information
Class of Control is configured using Partitions and Calling Search Spaces (discussed in the
following sections).
Partition
A Partition is a grouping of things with similar reachability characteristics. In general, you
can think of a Partition as being assigned to things you can dial, such as the following:
DNs
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Route Patterns
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Translation Patterns
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Voicemail Ports
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Meet-Me Conference Numbers
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By default, one Partition exists; it is called the Null Partition, although it is listed in the
CUCM web pages as <none>. Up to 75 additional Partitions can be created at once.
Calling Search Space
A Calling Search Space is a top-down ordered list of Partitions. A Calling Search Space
can be applied to a device (such as an IP phone or gateway), or to a line on the IP phone.
One CSS exists by default, and by default, it contains only the Null Partition. You can
think of a CSS as being assigned to things that can place calls.
Interaction of Partitions and Calling Search Spaces
The essential thing to understand is this: If the target that is being dialed does not exist in
one of the Partitions in the CSS of the caller, the call will fail. This behavior allows us to
design specific calling-privilege schemes and apply them to different calling devices or
lines. Consider the following example: A company wants to implement call restriction
such that the lobby phones cannot place long-distance calls. A new Partition is created
called “PSTN_Local_PTN.” The Route Patterns that match 7-digit and 10-digit (toll free)
PSTN calls are assigned to the PSTN_Local_PTN Partition.
A new CSS is created called Lobby_CSS. The PSTN_Local_PTN Partition is added to the
Lobby_CSS.
The Lobby CSS is applied to the lobby phones configuration. As soon as that change is
made, the lobby phones will get the reorder tone when they try to dial any number that
does not match the 7- or 10-digit patterns in the Lobby_CSS. Thus, no one can abuse the
lobby phones and cost the company toll fees by making long-distance calls.
A few related points:
If a user tries to call 911 from the lobby phone, that call will fail too, unless the emer-
gency call patterns are also added to the PSTN_Local_PTN Partition or to another
Partition that is in turn added to the Lobby_CSS. It is generally a good idea to ensure
that every phone can place emergency calls.
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