The following classes provide telephony services in the Qt Extended server.
| AbstractDialFilter | Interface for dial sequence filters |
| AsteriskManager | Maintains information about the active Asterisk telephony service |
| CellBroadcastControl | Monitors incoming cell broadcast messages |
| CellModemManager | Simplifies the initialization and monitoring of a cellular phone modem |
| DialProxy | Generic dial string processing and enables the routing of dialtone and call audio |
| DialerControl | Convenient interface to the phone call manager |
| DtmfAudio | Simple interface for playing DTMF tones |
| ExternalAccess | Starts the modem emulator on a serial port to allow external access via a serial cable |
| GSMDialFilter | GSM dial filter required for GCF compliance |
| JabberManager | Maintains information about the active Jabber telephony service |
| MessageControl | Message related management services |
| NetworkRegistrationUpdate | Notifications for the user when the network registration of any network (e.g. VoIP or Cell) changes |
| PhoneServer | Represents the central dispatch server for phone requests |
| QAbstractCallPolicyManager | Interface for the management of calls across multiple call types |
| RingControl | Controls the system ring for incoming calls and messages |
| SimCallHistory | Populates the in-memory call history list with entries provided by the call history list stored on a SIM card |
| SimControlEventHandlerTask | Feedback about SIM control events to the user |
| SupplementaryServiceTask | Notification about unstructured notifications within GSM networks |
| VideoRingtone | Interface to the Qt Extended media system to play the video tones for incoming calls |
| VoIPManager | Maintains information about the active VoIP telephony service |