The Phone Server authenticator can create a virtual extension when an account is created. These extensions are used to route incoming calls to connected users or a built-in voice mail service if the user is not connected or answering.
If you enable answering Phone Server will pick up the line only if it detects at least one virtual extension has been assigned to an account. Once the decision to answer has been made, if Phone Server detects a single allocated extension it will route the call either to the user if they are connected, or to the single voice mail box as appropriate. If there is more than one virtual extension Phone Server must first query the caller to elicit the desired user they wish to contact by asking for the virtual extension. Once this callee has been successfully identified Phone Server will route the call to the callee if they are detected or present a voice mail option if they are not.
The caller, once they have identified the the callee, can also now enter the particular voice mailbox password. This identifies them as the owner of the mailbox and allows them to retrieve and manage their voice mail. They can also create or manage their own custom greeting message. The owner of the voice mailbox can set their password only from a connection with NetCaller.
Since voice mail is produced as raw audio files generated from the modem, the files can grow quite large as will the storage for the extension. This is why Phone Server offers the option of compressing the stored audio files. Like most audio compression schemes, there is a loss of quality but this will provide a savings of about a factor of 16 in storage requirements. In all cases, when the owner of the voice mail retrieves it via NetCaller the data is compressed in order to best conserve bandwidth.
