On the Extensions page (click the Phones link), the SIP Soft Switch displays the current status of configured extensions, including total number of configured extensions and total number of extension license used.

Number - The extension of the phone. Click the extension link to view additional details:

Expires - The remaining number of second the dynamic registration information stays valid for the phone. The phone should renew the registration before it expires; otherwise, the non-statically configured extension becomes unavailable to receive calls.

Forward - The destination for unconditional forwarding. Typically, forwarding can either be configured from the Forwarding tab of phone's dial plan configuration, or using a third-party call control (CSTA API) client, such as Microsoft Office Communicator for the Microsoft Live Communicator 2005 Server integration.

Edit button - Click to open the corresponded dial plan configuration entry for this phone.

Display Name - The display name as configured for this extension in the SIP Soft Switch.

Registration Status - Indicates whether the phone's registration is active, expired, or never registered. Statically configured extensions typically never register, but an extension license is allocated. For extensions with dynamic registration (concurrent license mode), the never registered status indicates the phone is not available to receive calls and a license is not yet allocated.

Available/Busy - Indicates if the phone is available or busy with a call.

IP - The statically configured IP address of the phone or last address from which the phone was registered.

User Agent - The user agent vendor-specific string. If not displayed, either the phone does not provide such information or no activity has yet occurred from that phone.

Out Of Service - Tracks misconfigured extensions. A value of Yes typically indicates DNS problems which occur when the phone is statically configured using the Host Name (as opposed to the IP address) and the SIP Soft Switch is unable to resolve the Host Name. Calls cannot be placed to Out Of Service extensions. To resolve the problem, make sure the Host Name of the phone can be resolved in DNS (verify by using the nslookup <hostname> command in the terminal window) or provide an IP address in extension's dial plan configuration. If the problem is resolved by fixing the DNS records, then re-load the SIP Soft Switch configuration information by navigating to the phone's dial plan configuration entry (SIP Soft Switch>Phones, then click the extension link) and click the Update button.

Ping button - Click to dynamically query the online status of the phone.