Local Directory

The Centrex Proxy Server® has integrated registrar capability built into the application. Registrar support allows call endpoints (SIP soft phones, hard IP phones and other SIP devices) to register with the proxy. When a "SIP device" registers with the proxy, it can then initiate and receive phone calls. The registry capabilities of the Centrex Proxy Server® are database oriented and dynamic. The number of registered uses can change at any time when users enter and leave (log in and log out) of your VOIP domain. This configuration dialog allows you to configure static registrar entries that are always loaded into the registrar database when the Centrex Proxy Server® starts.

Static registrar entries are useful if your SIP clients have the ability to SUBSCRIBE to registrar events that are offered by the Centrex Proxy Server®. A full detailed discussion of available registrar event types will be presented in the Registrar configuration dialog section of this document. For now, all you need to know is that any SIP client can be notified when users enter or leave the VOIP domain. With this information, intelligent SIP clients can present a list of users (or extensions) so that a person knows who is available to receive a call.


Here is a brief description of why static registrar entries are useful:

The Centrex Proxy Server® has the ability to send SIP clients user information via SIP NOTIFY events. This "user information" can be thought of as directory information. The information that the Centrex Proxy Server® sends to SIP clients represents all statically configured users as defined in the Local Directory configuration page and all dynamic users that enter and leave the VOIP domain using SIP REGISTER requests. When a SIP client registers with the proxy, it can also SUBSCRIBE to specific registrar events. If the SIP client doe this correctly, the SIP client will receive NOTIFY SIP messages whenever users enter or leave the VOIP domain. This type of capability is known as "presence". It gives SIP clients the ability to know who is available in the system.


 

The following dialog is used to set up static local directory information:

The configuration page consists of a single list control. To modify entries in the local directory list, use your mouse and right click anywhere in the list control. When you right click in the list control, you will see a pop up menu like the one shown in the dialog below:







The operations you can perform are:

Add - Adds a new local directory entry.
Edit - Edit an existing local directory entry.
Delete - delete an entry.
Copy - Allows you to duplicate an entry.
Save - Saves the current changes to the local directory database.

The information that is maintained for each local directory entry has two parts, the user name (or phone extension) and the user definable directory description of the entry. For example, when you add a new local directory entry to the list, the following dialog will be displayed:






Enter the user name (or phone extension) and the directory information for the user. Press the OK button when you are done.



In summary: If an intelligent SIP client subscribes to registrar NOTIFY events using SIP SUBSCRIBE messages, the SIP client can display active directory information to the user.