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:
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
Delete - delete an entry.
Copy - Allows you to duplicate
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.