Cisco Systems 1.4 Manual De Usuario

In a Cisco CallManager setup, each phone extension is assigned to a partition and a calling search space.

A partition is a group of devices with similar reachability characteristics. Devices you can place in 
partitions include IP phones, extensions, and gateways. By default, extensions are assigned to the “none” 
partition. The “none” partition is a default setting in Cisco CallManager that is treated as the null or 
non-existent partition.

A calling search space is an ordered list of partitions. When a user makes a call from an extension, the 
call can only be completed if the dialed number is within a partition identified in the calling search space. 
The calling search space always includes the none partition.

Calling search spaces and partitions make it possible to separate parts of your phone network. This can 
be useful if you are providing phone service to a large building occupied by separate companies or 
organizations (such as an office tower).

You must configure partitions and calling search spaces in Cisco CallManager to enable 
Personal Assistant to intercept calls and support rule-based call routing.

Cisco CallManager allows you to create clusters of Cisco CallManager systems that share a common 
database. Cisco CallManager clusters provide a mechanism for distributing call processing seamlessly 
across a converged IP network infrastructure to support IP telephony, to facilitate redundancy, and to 
provide feature transparency and scalability.

If you are using Cisco CallManager clusters in your IP telephony network, it is important to understand 
how Personal Assistant interacts with them. The number of clusters you have affects the number of 
Personal Assistant servers you need.

The pool of addresses that you create in Cisco CallManager to support Personal Assistant (interceptor 
ports, CTI route points, translation patterns, and media ports) is registered with the primary 
Cisco CallManager server in the cluster. Each Personal Assistant server can register with multiple 
primary Cisco CallManager servers, based on the telephony provider to which these route points and 
ports belong.

When the primary Cisco CallManager system of a media port goes down, the Personal Assistant server 
is notified and attempts to register with the secondary Cisco CallManager systems in the cluster, 
proceeding in a round-robin fashion. Once Personal Assistant establishes a connection with a secondary 
Cisco CallManager server, it registers the media port with it. When the primary Cisco CallManager 
system is online, the Personal Assistant server will re-register with it.

To understand how Cisco CallManager clusters affect rule-based call routing, assume that you have two 
users whose IP phones are configured within the same Cisco CallManager cluster. User A configures a 
Personal Assistant rule that forwards all her calls to the extension of User B. When the call is transferred 
to User B, the call is not intercepted as an incoming call; it is simply transferred. Any Personal Assistant 
rules configured by User B do not take effect.

However, if these two users are in separate Cisco CallManager clusters, calls are not simply transferred. 
Instead, the transferred call from User A (in Cisco CallManager Cluster 1) is treated as an incoming call 
to User B (in Cisco CallManager Cluster 2). Because it is treated as an incoming call, any rules that User 
B has configured go into effect. This might erroneously cause calls for User A to have rules processed 
and applied as if they were calls to User B.