This topic describes how to manage the Cisco Unity Express application ports.
- The number of application ports cannot exceed the available Cisco Unity Express module ports.
- Configure maximum sessions so that each application will have at least one port available for an incoming call.
- Example: Module maximum 8 ports, 3 applications each with a maximum of 4, 3, and 3 ports. Worst-case scenario comes if any two applications reach maximum sessions (4 + 3 = 7 ports used).
One of the parameters that administrators can configure for the voicemail and auto-attendant applications is the maximum number of callers who can concurrently access the application at any specific time. This parameter, called maxsessions, is limited by the number of ports on the Cisco Unity Express module.
Consider the expected call traffic when you assign the number of ports to an application. One application might need more ports than another, but each application must have at least one port that is available for incoming calls.
For example, the Cisco Unity Express module has four ports and the administrator assigns four ports to the voicemail application and four ports to the auto-attendant. If four callers access voicemail simultaneously, no ports will be available for auto-attendant callers.
Suppose, instead, that the administrator assigns three ports to the voicemail application and three to the auto-attendant. At no time will one application use all four ports. If voicemail has three active calls, one caller can still access the auto-attendant. A second call to the auto-attendant will not go through at that moment.
Similarly, the administrator must assign the maxsessions parameter to each application trigger, which activates the script of the application. The value of the maxsessions parameter for the trigger cannot exceed the maxsessions value of the system.
As shown in the figure, the Cisco Unity Express module has a maximum of eight available ports. Three applications (called Auto-Attendant, Voicemail, and Prompt Management) are each configured with 4, 3, and 3 ports maximum, respectively. In the worst-case scenario, if any two applications reach their maximum sessions, there will always be at least one port available for the remaining application. That is, if the application called Auto-Attendant and another application are out of their free capacity, the total ports in use is 7 (4+3), therefore leaving one port free for the remaining application.