Mailbox
The mailbox subsystem is able to welcome callers with different standard and customized messages that can be set up by the users of the mailbox. Upon reception of new messages, the mailbox sends message waiting indications (MWI) to predefined destinations or to user agents that have subscribed to these notifications. New messages can be forwarded to POP3 email accounts. The recorded messages may be sent to the users via Email. The attachments are compressed via a low-rate speech codec and can be played on email programs like Microsoft Outlook.

Music on Hold
The music on hold server can be used to entertain waiting users. Users may select their music with DTMF. The music can be set up with standard WAV-files.

Conference Server
The conference server can mix multiple conferences with multiple participants. It is possible to set up password protected conference accounts. The conference server is able to mix conferences with mixed codecs. The media server supports ad-hoc conferences with or without password.

Auto Attendant and IVR
The auto attendant welcomes callers with a customized message and redirects calls to predefined destinations or to extensions that can be entered with DTMF. The auto attendant is controlled by a dial plan that lists the available destinations in a table-like fashion. Wildcards make it easy to set up the auto attendant for large installations. IVR trees can be used to guide callers through voice prompts. Callers can navigate using their DTMF keys. This feature makes it easy to set up large corporation- style central numbers without any programming or XML.

The built-in web server makes setup and maintenance of the media server easy from any location around the world.

In-Band and Out-Of- Band

DTMF
The media server detects both in-band and out-of-band DTMF (RFC2833). Callers can use different codecs such as G.711 and GSM (G.729a/b upon request). GSM 6.10 is important if Microsoft Messenger is to be used. The codec preferences can be set up with the built-in webserver. Due to its real-time nature, the media server needs to be run on a responsive server that has no other significant load. Both Windows and Linux operating systems based on Intel 386 compatible CPUs are supported.

Customization
Experienced users can extend the functionality of the media server by recording new WAV audio files and by setting up their own account types in XML files. In this way, functions like wake-up services and calling card can be implemented. Using the media server together with a forking proxy like the Snom Registrar/Proxy, call distribution can be implemented. The media server can be used in a server farm for maximum scalability. It supports DNS NAPTR (ENUM), SRV, loose routing and TCP transport layer for maximum compatibility with other SIP components.

Open API
The Media Server can be scripted like a state machine. Using a simple XML-based language, transitions can be described based on state and events. This allows for very flexible application development. For example, the SI Calling Card Solution is based on scripting the Media Server to provide prepaid Calling Card functionality.