Cisco Systems 1.4 Manual Do Utilizador

If you defined more than 18 media ports on server A and server B, the servers will not be able to take on 
the full load of the other server if it becomes disabled. For example, if you define 18 ports on server A 
and 24 on server B, and server A fails, Personal Assistant assigns 42 ports to B. If the simultaneous call 
load exceeded 36, calls would be dropped (because each server supports a maximum of 36 media ports) 
and the quality of service experienced by your users would deteriorate.

In general, if you use active Personal Assistant servers as failovers, you should divide the ports per server 
in half, and double the number of Personal Assistant servers in the cluster.

Although you can assign more than one Personal Assistant server to handle failover for any given server 
(for example, server A could use server B and server C as failovers), only one server is actually used if 
a server becomes disabled. The disabled server ports are not distributed among the designated failover 
servers.

When you use a spare Personal Assistant server as a failover server, it sits idle unless an active server 
becomes disabled.

To create a spare server, do not define a CTI route point in Cisco CallManager for that server. When an 
active server becomes disabled, the spare server registers itself with Cisco CallManager as the CTI route 
point, in place of the disabled server.

When adding a spare server to a Personal Assistant server cluster, do not define any media ports or 
interceptor ports (see the 

), thus preventing the server from 

being used for anything except failover.

Because a spare failover server does not have any active ports, it can take over for a fully-loaded 
Personal Assistant server. For example, if you are using MCS-7835-H1-IPC1 systems for your active and 
spare servers, you can configure 36 media ports on the active server. If the active server becomes 
disabled, the spare will be able to take over the 36 media ports.

Because servers should seldom become disabled, you can have fewer failover servers than you have 
active servers. For example, you might define two failover servers for six active servers. The ratio you 
use depends on your network reliability and uptime service level agreements. The key is that a failover 
server must be able to take over all the media ports you define on an active server.

Personal Assistant interacts with Cisco CallManager to intercept incoming calls to user extensions. By 
intercepting these calls, Personal Assistant can redirect them based on user rules. For example, a user 
can configure a rule that instructs Personal Assistant to send all incoming calls to voice mail.

Although Cisco CallManager does not require that you set up partitions, you must create partitions if 
you install Personal Assistant and want to enable the rule-based call routing feature or 
Personal Assistant.

If you are not yet using partitions and calling search spaces in Cisco CallManager, the following 
examples provide tips on setting them up with the minimum amount of effort. If you do not set up and 
configure partitions and calling search spaces, Personal Assistant cannot intercept user calls. You can, 
however, still use the speech features provided by Personal Assistant, such as dial-by-name and 
speech-enabled voice mail access (see the 

).

The following sections provide examples of using partitions and calling search space in your IP 
telephony network before and after adding Personal Assistant: