Virtual telephone

Abstract

A telephone communication system utilizing a virtual phone wherein a telephone switch or similar digital switching device, a digital telephone and an external device such as a personal computer (PC) or other processor are generically interfaced. The virtual phone generic interface is configurable and comprises a set of virtual phone data structures, internal and external virtual phone application program interfaces, and an external transfer protocol. Software designated an abstraction layer provides communication between the internal virtual phone application program interface, the telephone switch and the telephone set. The generic interface converts proprietary telephone switch or external interface application protocols into a common format and functions as a protocol interpreter between proprietary switching system protocols and protocols of various applications.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the invention

[0002] The present invention relates generally to a telephone communication system and, in particular, to a device that provides a generic software interface to a digital line on one of many different types of digital phone switches. A telephone with such a generic interface is a “virtual phone” that has the flexibility to represent the majority of features of any digital phone, regardless of the switch type or the number of features in a digital phone.

[0003] The general concept of a virtual telephone has been in existence in various forms across different product lines. In some cases a virtual phone has been used to represent a specific digital phone, such as Rolm Phone 400 or a Meridian 2616. Those phones represent a superset of phones for their respective switches. In other cases a virtual phone has been used to represent only the necessary portions, or a subset, or a digital telephone.

[0004] 2. Prior Art

[0005] One of the important characteristics of a telecommunication system is the ability of different interconnected components of the system to effectively communicate with each other. Many business-oriented telecommunication systems have PBX (Private Branch Exchange) switches that link internal telephones with each other and with external telephone networks.

[0006] Even though today most vendors build the PBXs around common available processors running common operating systems (such as UNIX) and use common programming languages (such as C or C++), unfortunately different vendors' switching devices use proprietary communication protocols. Thus, it is virtually impossible to integrate one vendor's switching device with other vendors' applications.

[0007] Therefore, it becomes highly desirable to provide a telecommunication system with a feature that would convert proprietary PBX or external application protocols into a common format, and thus would function as a “protocol interpreter” between proprietary switching system protocols and the protocols of various applications.

[0008] A number of solutions to that problem have been disclosed in the prior art. For example, U.S. Pat. No. 4,873,718 “Feature Telephone Integration Device” issued to Barnett et al discloses a device and method for integrating one vendor's application (a voice mail system) into a PBX environment of a different vendor. In that patent the interconnection was achieved by equipping the PBX vendor's feature phone with additional circuitry to monitor telephone communication between the PBX, the feature telephone and the external application. An obvious disadvantage of the disclosed system is its inability to provide a generic interface between many possible proprietary protocols of different PBX switching systems and an external application. The disclosed invention provided integration only between a PBX and a voice mail system, it did not provide for the possibility to integrate a PBX with a variety of different external applications. Moreover, any exchange of information about a call or a change of the status of the call occurs “one-way” only: from the PBX to the telephone set.

[0009] U.S. Pat. No. 5,440,616 provides an improvement over the device of U.S. Pat. No. 4,873,718 in the form of apparatus for interconnecting a messaging system (voice, facsimile, etc.) with a PBX which offers entirely digital transmission and provides high bandwidth and redundant transmission of control information between the messaging system and the PBX. The apparatus of U.S. Pat. No. 5,440,616 includes a digital voice terminal adapter which is a combination of hardware and software which emulates a digital feature phone and which interconnects a messaging system and a PBX to provide full integration of the messaging system with the PBX. The disclosed adapter does not, however, convert proprietary/PBX or external application protocols into a common format and thus does not function as a protocol interpreter between proprietary switching system protocols and the protocols of various applications.

[0010] U.S. Pat. No. 5,255,314 “Switch Adjunct Integration Device” issued to Applegate et al discloses a device that uses multiple line appearances of one or more digital telephone lines to gather information on calls designed for an adjunct voice mail system. After receiving the required information the device transfers the calls to analog phone lines leading to the voice mail system. That device, again, provides no more than a communication tool between a PBX switch and a voice mail system. The disclosed device does not integrate any type of the known PBX switches with any type of external device via a generic interface.

SUMMARY OF THE INVENTION

[0011] Advantageously, the present invention overcomes the “protocol conversion” difficulties which existed in the prior art. The virtual phone generic interface of the present invention comprises three distinct modules: a virtual phone data structure, a program interface, and a host interface. All three modules can work independently of a specific type of integration. The data structure and the program interface software of the virtual phone are built into the embedded processor that controls the Private Branch Exchange (PBX) digital phone switching system interface integration. The interface between the switch and the virtual phone data structure is different for each integration, but once the interface is completed, it can be reused for many different types of applications. The interface between the virtual phone structures and the external application is the same regardless of the type of integration.

[0012] The implementation of the virtual phone provides for an external interface through any type of transport medium. A phone application residing on an auxiliary PC can show the current status of the virtual phone, and can also do call control. This illustrates the common external interface and also provides a method for diagnostics. The interface to the auxiliary PC is accomplished in different ways based on the system configuration. It can be done via a serial port, ISA bus, PCI bus, universal serial bus, Ethernet, or any other type of transport configurable. An internally designed protocol is used to communicate between the virtual phone and the auxiliary PC. In essence, the virtual phone acts as a protocol converter between the proprietary switch messages and the external serial interface.

[0013] The virtual phone of the present invention provides a common interface between any of the digital phone switches and any number of end devices. The virtual phone represents the current state of some theoretical phone and has buttons, lights, a hook switch, display, ringer, and anything else typical of a standard digital phone. The main component of the virtual phone is a set of structures that represent the state of the phone at any given time. The virtual phone structures can be accessed via a set of Virtual Phone Application Program Interface (VPAPI) function calls. The virtual phone status and events are transmitted externally via a custom virtual phone host interface.

[0014] When a packet is received from a switch, an abstraction layer parses the data and calls an internal VPAPI function. The internal VPAPI function is responsible for updating the virtual phone structure and passing the information about any state changes to an auxiliary PC through the virtual phone host interface. An internally designed protocol is used to provide communication between the virtual phone and the auxiliary PC through the host interface such as a standard RS232 communications port. A phone application residing on the auxiliary PC can show the current status of the virtual phone and accomplish call control tasks. So, in essence, the virtual phone functions as a “protocol interpreter” between the proprietary switch messages and the external interface.

[0015] When an event is received from the auxiliary PC, an external VPAPI function is called to update the virtual phone. The event is passed to an abstraction layer where it is converted to a command format in accordance with a specific virtual phone integration. The command is then subsequently passed to the switch.

[0016] The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description together with the included drawing wherein:

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0017] FIG. 1 is a block diagram of the telephone communication system of the present invention;

[0018] FIG. 2 is a block diagram illustrating the system of FIG. 1 in different types of phone integration implementations;

[0019] FIG. 3 is a block diagram further illustrating the virtual phone application program interface of the systems of FIGS. 1 and 2;

[0020] FIG. 4 is a block diagram of an illustrative implementation of the abstraction layer in the systems of FIGS. 1 and 2; and

[0021] FIG. 5 is a block diagram illustrating a generalized form of the system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] Telephone Communication System

[0023] A telephone communication system utilizing the virtual phone of the present invention is shown in FIG. 1 wherein a PBX or similar digital switching device 12, a digital telephone 14 and an external device such as a personal computer (PC) or other processor 16 are interfaced by the arrangement 18 of the present invention. The virtual phone generic interface 18 of the present invention comprises a set 20 of virtual phone data structures, internal and external virtual phone application program interfaces 22 and 24, respectively, and a virtual phone host interface 26. Software designated hardware abstraction layer 28 provides communication between the internal virtual phone application program interface 22, PBX 12 and the telephone set 14.

[0024] Switch 12 can be a PBX, KSU, service provided by a central office (such as Centrex or ISDN) and does not even have to digital. Digital telephone 14 is representative of other communication devices like phones using emerging network interface technologies like internet protocol (IP), isoethernet, various forms of wireless, ATM, etc. Various types of additional telephones (ex. switch dependent phones, analog phones, cordless phones, conference phones), modems, fax machines or computers can be connected to the primary communications device 14.

[0025] Virtual Phone Structure

[0026] The actual virtual phone is represented by a set 20 of data structures, for example “C” language data structures that maintain the current status of the theoretical, i.e. virtual, phone. The data in these structures may change when an event occurs on the switch 12 or an adjunct digital phone 14, and the data gets passed up through the abstraction layer 28 and VPAPI 22. Also, the virtual phone structure information can change if an authorized external device 16 sends a VPAPI command 24.

[0027] The virtual phone structure 18 requires several bytes of RAM within the address range of an embedded microcontroller. The current state of the structures 20 matches what the switch 12 believes the digital phone 14 to be. Since it is possible for applications in processor 16 to take control away from the digital set 14, the virtual phone 20 and the digital phone 14 will not always have matching states. For example, if a digital phone and a cordless phone are connected to the same line, and voice is routed to the cordless, the switch thinks voice is active, and the digital phone does not.

[0028] The messages sent form the telephone switch 12 provide a representation of the state of the telephone 14 as it resides internally in the switch. The virtual phone 18 translates this state into a form that is not switch or phone dependent, but one that can represent any desired telephone or communications device. The virtual phone 18 is protocol and transport dependent.

[0029] The virtual phone system of the present invention is designed to fit the needs of different types of phone integration implementations. Of the three major components of the software system (Virtual Phone Structure 20, VPAPI 22, 24 and VPHI 26), not all need to be used in every system implementation. This is illustrated in the overview of FIG. 2.

[0030] In a first typical implementation, there is a case where the host interface is not needed. When an external communications device 34 is integrated into the system, the host protocol is unused. The external device 36 can be controlled directly from the system software within the micro-controller via the VPAPI 24 via an integrated link 38.

[0031] The auxiliary PC 16 from the arrangement of FIG. 1 is shown connected to host interface 26′ via an RS232 link 40.

[0032] In another example, all three major components are used. The external communications device is a computer 44 with an ISA link 46 to the virtual phone system. This host computer 44 runs a TAPI application. As messages are received from the switch 12, the abstraction layer 28 calls VPAPI functions which update the virtual phone structures 20 and convert the commands into a generic protocol that can be easily understood by the host system 44. Optionally, the data does not even need to be maintained in the virtual phone structures. The system can act simply as a protocol converter.

[0033] Also shown in the example of FIG. 2 is a network application 50 linked to the virtual phone system via a TCP/IP protocol link 52.

[0034] The virtual phone data structures 20 of the virtual phone system 18 of FIGS. 1 and 2 first will be described in detail, followed by description of the virtual phone application program interfaces 22, 24 and the abstraction layer 28. Accordingly, the following represents a description of all of the structures and defined variables that make up the structures 20 of the virtual phone system 18.

[0035] Main Control Structure

[0036] The following “C” language code illustrates the main virtual phone structure. One instance of this data structure is used to represent a single digital port.

typedef struc		/* Main Virtual Phone
		Structure */
VP_VOICE	voice;	/* voice status */
VP_RINGER	ringer;	/* ringer status */
VP_DISPLAY	display;	/*LCD display status */
BYTE	num_buttons;	/* number of buttons
		actually in use */
VP_BUTTON	button	/* button/lamp status */
	[VP_MAXBUTS];
BYTE	StandAlone;	/* operate without
		digital set */
BYTE	SwitchType;	/* type of switch
		connected */
BYTE	DigSetType	/* Type of configured
		digital SET, if */
BYTE	Connections;	/* Which Phone Units
		are physically connected
		*/
BYTE	ActivePhone;	/* Which Physical Phone
		Unit is active */
BYTE	TouchedPhone;	/* Which Physical Phone
		Unit was last touched */
BYTE	Carrier[2];	/* 0=switch 1=digital
		set */
BYTE	PassThroughFlags;	/* event block flags */
BYTE	Voicemux;	/* Bearer channel
		direction */
VIRTUAL—
PHONE;
VP_VOICE	voice	References the voice
		control element of the
		virtual phone. This
		is described in
		greater detail in the
		section titled “Voice
		control structure”.
VP_RINGER	ringer;	References the ringer
		control element of the
		virtual phone. This
		is described in
		greater detail in the
		section titled “Ringer
		control structure”.
VP_DISPLAY	display	References the display
		control element of the
		virtual phone. This
		is described in
		greater detail in the
		section titled
		“Display control
		structure”.
BYTE	num_buttons;	The number of the
		virtual buttons
		actually in use by the
		virtual phone.
		Although the virtual
		phone can support many
		buttons, some
		applications may limit
		the number of buttons
		in use.
VP_BUTTON	button	References the button
	[VP_MAXBUTS];	control element of the
		virtual phone. This
		is described in
		greater detail in the
		section titled
		“Button/Lamp control
		structure”.
BYTE	StandAlone;	When TRUE, the system
		is operating without
		an adjunct digital
		phone. When FALSE, an
		adjunct digital phone
		is connected and
		operating.
BYTE	SwitchType;	The brand of PBX (or
		KSU) connected to the
		system. The valid
		phone types are
		represented by the
		following defines:
#define	PBX_NONE	0	/* No PBX connected */
#define	PBX-ATT	1	/* AT&T switch
			connected */
#define	PBX_M1	2	/* Meridian switch
			connected */
#define	PBX_NORSTAR	3	/* Norstar switch
			connected */
#define	PBX_ROLM	4	/* Rolm switch
			connected */
#define	PBX_ISON	5	/*ISON switch connected
			*/
BYTE	DigSetType;		The type of digital
			phone connected to the
			system. The valid
			phone types are
			represented by the
			following defines:
#define	SET_NONE	0	/* Only when no PBX */
#define	SET_UNKNOWN	1	/* Connection, Unknown
			type */
#define	SET_ROLM_400	10	/* Rolm Phone 400 */
#define	SET_ROLM_240	11	/* Rolm Phone 240 */
#define	SET_ROLM_120	12	/* Rolm Phone 120 */
#define	SET_ROLM_600	13	/* Rolm Phone 600 */
#define	SET_ROLM_300	14	/* Rolm Phone 300 */
#define	SET_M1_2616	30	/* M1 2616 */
#define	SET_NOR_7310	50	/* Norstar 7310 */
#define	SET_NOR_7208	51	/* Norstar 7208 */
#define	SET_NOR_7100	52	/* Norstar 7100 */
#define	SET_NOR_7310LF	53	/* Norstar 7310 BLF */
#define	SET_NOR_7324	54	/* Norstar 7324 */
#define	SET_ATT_7405	70	/* AT&T 7405 */
#define	SET_ATT_7406	71	/* AT&T 7406 */
#define	SET_ATT_7407	72	/* AT&T 7407 */
#define	SET_ATT_7434	73	/* AT&T 7434 */
#define	SET_ISON_1	90	/*ISON 1 */
BYTE	Connections;		A mask of all of the
			physical phone
			connections made to
			the system. Multiple
			phones may be
			connected at any time.
			If the bit represented
			by the following
			defines is set in this
			field, the associated
			unit considered
			connected.
#define	PHONE_NONE	0X00	/* No phones connected
			*/
#define	PHONE_ADJUNCT	0x01	/* the Standard digital
			set */
#define	PHONE_AUX	0x02	/* phone app via debug
			port */
#define	PHONE_CONF	0.04	/* conference speaker
			phone */
BYTE	ActivePhone;	Identifies which
		physical phone unit is
		currently active. A
		phone is defined to be
		active if it has
		control of the voice
		channel. The valid
		values for this field
		are the same as those
		defined for the
		“Connections” field
		above.
BYTE	Touched Phone;	Identifies which
		physical phone unit
		was last used by the
		operator. This is
		used to determine the
		unit to receive
		“active” status. The
		valid values for this
		field are the same as
		those defined for the
		“Connections” field
		above.
BYTE	Carrier [2]	Identifies the carrier
		status of the switch
		and the phone. The
		first set of defines
		indexes the unit, the
		second set represents
		the status.
#define	CARRIER_DEVICE—	0/* switch device */
	SWITCH
#define	CARRIER_DEVICE—	1/* phone carrier device
	ADJUNCT	*/
#define	CARRIER_LEVEL—	0/* No carrier */
	LOSS
#define	CARRIER_LEVEL—	1/* Carrier */
	GAIN
#define	CARRIER_LEVEL—	2/* Unknown carrier
	UNKNOWN	state */
BYTE	PassThroughFlags	A bit mask used to
		inform the abstraction
		layer which types of
		events should be
		passed between the
		switch and the phone,
		and which should be
		blocked.
#define	PASS_HOOK	0x01	/* hook switch
			from set */
#define	PASS_BUTTON	0x02	/*buttons from set
			*/
#define	PASS_LAMP	0x04	/*lamp updates
			from switch */
#define	PASS_DISPLAY	0x08	/* display update
			switch */
#define	PASS_RINGER	0x10	/* ring updates
			switch */
BYTE	VoiceMux;	Identifies the
		direction of each of
		the available bearer
		channels. This is a
		bit mask with each bit
		representing each of
		the channels.
		There is typically one
		bit for the voice
		channel, and at least
		one bit for available
		data channels. When
		the bit is low, the
		channel is directed to
		the adjunct digital
		telephone. When the
		bit is high, the
		channel is directed to
		the alternate device.
#define	VMUX_ADJUNCT	0	/* channel to
			digital set */
#define	VMUX_AUX	1	/* channel to
			alternate */
#define	VMUX_VOICE	0x01	/* bit 0: voice
			channel */
#define	VMUX_DATA	0x02	/* bit 1: 1st
			data channel */
#define	VMUX_DATA1	0x02	/* bit 1: 1st data
			channel */
#define	VMUX_DATA2	0x04	/* bit 2: 2nd
			data channel */

[0037] Voice control structure

[0038] The following “C” language code defines the structure used to represent the state of the voice channel. A single instance of this structure is built into the main virtual phone structure.

	typedefstruct		/* Virtual Phone Voice
			Structure */
	BYTE	active;	/* 1=active 0=not active
			*/
	BYTE	unit;	/* mask active unit
			VOICE_???? */
	BYTE	volume;	/* voice mute, low, high,
			etc. */
	VP_VOICE
	BYTE	active;	When TRUE, the voice
			path is currently
			active. When FALSE, the
			voice path is not
			active.
	BYTE	unit;	Which unit (within the
			confines of the digital
			set) is currently used
			as the communications
			source.
	#define	VOICE_HANDSET	0x10	/* Phone Handset
				Unit */
	#define	VOICE_SPEAKER	0x20	/* Phone Speaker
				Unit */
	#define	VOICE_HEADSET	0x30	/* Phone Headset
				Unit */
	BYTE	volume;	The current sound level at
			which the system is
			operating.
	#define	VOICE_MUTE	0x01	/* Volume is muted
				*/
	#define	VOICE_NORMAL	0x02	/* Volume is normal
				*/
	#define	VOICE_LOW	0x03	/* Volume is low */
	#define	VOICE_LOW	0.04	/* Volume is high
				*/

[0039] Ringer control structure

[0040] The following “C” language code defines the structure used to represent the ring state of the virtual phone. A single instance of this structure is built into the main virtual phone structure.

	typedefstruct		/* Virtual Phone
			Ringer Structure
			*/
	BYTE	active;	/* 1:active 0=not
			active */
	BYTE	cadence;	/* list of
			current cadence
			type */
	BYTE	tone;	/* list of
			current tone type
			*/
	VP_RINGER;
BYTE	active;	When TRUE, the ring state
		of the virtual phone is on.
		Typically, an audible ring
		indication can be heard.
		When FALSE, the ring state
		is off.
BYTE	cadence;	One of the many difference
		types of ring cadence
		patterns a phone may
		select. This is valid when
		the ring state is active.
#define	RINGER_CAD_OFF	1	/* ring off */
#define	RINGER_CAD_ON	2	/* ringer on steady */
#define	RINGER_CAD_2	3	/* ringer some on/off
			comb. */
	BYTE	tone;	Once of the many different ring tones
			a phone may select. This is valid
			when the ring is active.
#define	RINGER_TONE_OFF	1	/* tone off */
#define	RINGER_TONE_A	2	/* tone A */
#define	RINGER_TONE_B	3	/* tone B */
#define	RINGER_TONE_C	4	/* tone C */
#define	RINGER_TONE_D	5	/* tone D */
#define	RINGER_TONE_E	6	/* tone E */
#define	RINGER_TONE_F	7	/* tone F */
#define	RINGER_TONE_G	8	/* tone G */
#define	RINGER_TONE_H	9	/* tone H */

[0041] Display control structure

[0042] The following “C” language code defines the structure used to represent the LDC display of the virtual phone. A single instance of this structure is built into the main virtual phone structure.

typedefstruct		/* Virtual Phone
		Display Structure */
BYTE	grid [VP_MAXROWS]	/* The display text
	[VPD_MAXCOLS];	*/
VP_CURSOR	cursor	/* current cursors*/
	[VPD_MAXCURSORS];
BYTE	NumRows;	/* Number of Rows on
		this page */
BYTE	NumColumns;	/* Number of Columns
		on this page */
BYTE	NumCursors;	/* Number of
		available cursors */
BYTE	IsStable;	/* True if the
		display has
		stabilized */
BYTE	IsClear;	/* True if the
VP—		display is clear */
DISPLAY;
BYTE	grid [VPD_MAXROWS]	The 2 dimensional
	[VPD_MAXCOLS];	array containing the
		characters on the
		display of the
		virtual phone. Each
		cell of the grid
		contains the
		character value in
		ASCII format.
		VPD_MAXROWS and
		VPD_MAXCOLS can be
		defined to support
		virtual displays of
		various sizes.
VP_CURSOR	cursor	[VPD_MAXCURSORS];
		A list of cursors that
		are used by the
		display. Some
		displays have a
		single cursor, some
		have multiple
		cursors. This
		structure gives the
		abstraction layer
		control of all used
		cursor positions.
BYTE	NumColumns;	Number of columns on
		the display for the
		current virtual phone
		implementation.
BYTE	IsStable;	This is true if the
		display has been
		stable for a period
		of time determined by
		the abstraction
		layer. Only when the
		display goes stable
		does the information
		get transferred to
		the host.
BYTE	IsClear;	True if the display
		is clear.

[0043] The following “C” language code defines the structure used to represent a cursor device of the virtual phone. The display functions may use several cursors which must be maintained in order to generate the correct display. This structure is part of the main display structure.

	typedef struct			/* Virtual Phone
	{			Cursor Structure */
		BYTE	row;	/* Current row for
				this cursor */
		BYTE	col;	/* Current column for
				this cursor */
	}VP_BUTTON;
	BYTE	row;		Current row for this
				cursor within the
				current display.
	BYTE	col;		Current column for
				this cursor within
				the current display.

[0044] Button/Lamp control structure

[0045] The following “C” language code defines the structure used to represent a button/lamp device of the virtual phone. The main virtual phone structure uses a list of these items to represent all of the possible buttons/lamps on the phone.

typedefstruct		/* Virtual Phone
		Button/Lamp Structure
		*/
BYTE	deviceMask;	/* mask showing which
		of next 4 are valid
		*/
BYTE	press ID;	/* ID of button press
		info */
BYTE	release ID;	/* ID of button
		release info */
BYTE	lamp1ID;	/* ID of first lamp
		*/
BYTE	lamp2ID;	/* ID of second lamp
		*/
BYTE	buttonState;	/* state of button:
		1=down 0=up */
BYTE	lamp1State;	/* state of first
		lamp */
BYTE	lamp2State;	/* state of second
VP_BUTTON;		lamp */
BYTE	deviceMask;	A mask which
		identifies the
		available components
		of the button/lamp.
		In some cases, button
		may exist without a
		lamp, in others, 2
		lamps may relate to a
		single button. Also,
		some buttons have
		press and release
		codes, while others
		only have a press
		code. This mask
		validates the fields
		“pressID”
		“releaseID”,
		“lamp1ID”, and
		“lamp2ID” by setting
		the associated
		defined bit.
#define	VDP_MASKPRESS	0x01 /* “pressID” is
		valid */
#define	VDP_MASKRELEASE	0x02 /* “releaseID”
		is valid */
#define	VDP_MASKLAMP1	0x04 /* “lamp1ID” is
		valid */
#define	VD_MASKLAMP2	0x08 /* “lamp2ID” is
		valid */
BYTE	pressID;	The raw integration
		dependent ID sent to
		the switch when the
		button is pressed.
		This field is only
		valid when the
		VDB_MASKPRESS bit
		is set in the
		“deviceMask” field.
		Typically, all keys
		have this field
		active.
BYTE	releaseID;	The raw integration
		dependent ID sent to
		the switch when the
		button is released.
		This field is only
		valid when the
		VDB_MASKRELEASE
		bit is set in the
		“deviceMask” field.
		Typically, keypad
		buttons do not use a
		release ID.
BYTE	lamp1ID;	The raw integration
		dependent ID sent by
		the switch during a
		lamp update. This
		field is only valid
		when the
		VDB_MASKLAMP1 bit
		is set in the
		“deviceMask” field.
		Buttons that do not
		have associated
		lights (such as
		keypad buttons) will
		not use this field.
BYTE	lamp2ID;	The raw integration
		dependent ID sent by
		the switch during a
		lamp update. This
		field is only valid
		when the
		VDB_MASKLAMP2 bit
		is set in the
		“deviceMask” field.
		AT&T is the only
		integration known to
		use a second lamp for
		a button/lamp device.
BYTE	buttonState;	Current state of the
		button. All buttons
		can be pressed or
		released. The hook
		switch is considered
		pressed when off
		hook, and released
		when on hook.
#define	BUTTON_PRESS	1 /* button press */
#define	BUTTON_RELEASE	2 /* button release
		*/
BYTE	lamp1State;	Current state of the
		first (primary) lamp.
		The lamp can be in
		any of the following
		states.
#define	LAMP_STATE_OFF	1 /* lamp off */
#define	LAMP_STATE_ON	2 /* lamp on */
#define	LAMP_STATE_FLASH	3 /* lamp flashing
		*/
#define	LAMP_STATE_FLUTTER	4 /* lamp fluttering
		*/
#define	LAMP_STATE_WINK	5 /* lamp winking */
#define	LAMP_STATE_FLICKER	6 /* lamp flickering
		*/
#define	LAMP_STATE_MISC1	7 /* lamp misc */
BYTE	lamp2State;	Current state of the
		second lamp (AT&T is
		the only switch that
		uses this). The lamp
		can be in any of the
		states as in the
		“lamp1State” field.

[0046] Button/Lamp index descriptions

[0047] In the main virtual phone structure, the field “VP_BUTTON button [VP-MAXBUTS]” is used to store the button/lamp information for the virtual phone. The define VP_MAXBUTS determines the maximum number of buttons/lamps the virtual phone can contain. There are standard buttons in all configurations of the virtual phone. There are also additional buttons that may vary from phone to phone. The values shown below define the indices into the array of button/lamp control structures within the main virtual phone.

#define	KEY_HOOK	0 /* Hook switch key
		*/
#define	KEY_HOLD	1 /* Hold key */
#define	KEY_XFER	2 /* Transfer key */
#define	KEY_RELEASE	3 /* Release key */
#define	KEY_PAD	4 /* Key Pad 0-9, *,
		# */
#define	KEY_NONFIXED	16 /* -start of non-
		fixed buttons - */
#define	KEY_PRIME	16 /* Prime Line */
#define	KEY_OTHER	17 /*  */
KEY_HOOK	The hook switch. When pressed, it is
	considered off hook. When released, on
	hook. All integrations have this key.
KEY_HOLD	The standard hold key. All integrations
	have this key.
KEY_XFER	The transfer key. All integrations have
	this key.
KEY_RELEASE	The release key. All integrations have
	this key.
KEY_PAD	The start of the key pad keys. The
	sequence of keys are in the following
	order. 0 through 9, *, and #. All
	integrations have these keys.
KEY_NONFIXED	The starting ID of the non-fixed keys.
	Keys at this index for higher can be
	custom configured.
KEY_PRIME	The key associated with a prime line.
	When the switch has a prime line
	configured for a phone, this index should
	reference that key.
KEY_OTHER	Additional keys. Configuration is
	flexible.
VPAPI	(Virtual Phone Application Program
	Interface)

[0048] Access to the virtual phone structures is available through a set of symmetric functions known as the VPAPI 22 and 24. The VPAPI 22, 24 provides a mechanism to transfer data between the virtual phone data structures 20, and all devices (such as the switch 12, phones 14, and the external device 16). The data structures 20 are changed only via this interface, never directly by an external function 16. All elements of the data structures 20 can be modified, and read through the VPAPI 22, 24. Whenever the abstraction layer software 28 receives a change from the switch 12, digital phone 14, or external device 16, a call is made to a VPAPI function with parameters specifying the update request. The VPAPI function first validates the command request, and then makes the appropriate modification to the virtual phone structure.

[0049] As shown in FIG. 3, for different switches 12a, 12b, 12c and 12d and phones 14a, 14b, 14c, 14d from various vendors different abstraction layers 28a, 28b, 28c and 28d are provided. The VAPI 22, 24 also provide data transfer between the virtual phone data structures 20 and various devices such as serial devices 60, DSP 62, conference phones 64 and other devices 66.

[0050] Whenever a valid state change is made to the virtual phone structure 20, the VPAPI 24 calls a second function which is responsible for converting the information into a generic protocol (Host Interface 26), and transmitting it via the host interface 16 to the host system.

[0051] The abstraction layer 28 (and external device queries) often need information on the current state of the virtual phone. Symmetric VPAPI 22, 24 functions are used for this purpose and for all aspects of data access. In order to retrieve current status information and pass that information to the abstraction layer 28 and an external device 16, a function beginning with “vp_Get” is used. To modify data, “vp_Set” is used, which in turn automatically calls a function beginning with “vp_Send” for external transfer. Or, for example, to set a light state in the virtual phone structure, a call is made to “vp_SetLampState” with the lamp ID and state as parameters. For the abstraction layer 28 or external device 16 to get the light state, a call to the symmetric function “vp_GetLampState” is made.

[0052] The abstraction layer 28 (and external device queries) often need information regarding the current state of the virtual phone. Symmetric VPAPI functions are available for this purpose. Thus, during the processing of switch and phone packets, the abstraction layer 28 often calls the VPAPI functions 22, 24 to maintain current status of the digital phone 14 in the virtual phone data structures 20. Primarily, the “vp_Set” type functions are used. When a simulated event occurs, such as a generic cordless unit going off hook, the application code may also make a call to the “vp_Set” function, causing the system to be in the off hook state. Also note that in order for the simulated event to affect the switch, it must pass through the abstraction layer through an API function of the form “vprolm_DoButton” for example.

[0053] The hardware abstraction layer 28 is not part of the virtual phone, but is a system component used to interface between the switch 12 (and phone 14) and the virtual phone 18. The specifications for building this block vary for each switch type. In the example of FIG. 4, building of an ISDN integration is shown for use with an ISDN switch 72 and ISDN phone 74.

[0054] The first layer 80 (Physical layer) of the hardware abstraction can be built based on the international standards ITU I-series and ITU G-series documents. The second layer 82 (Data Link layer) is defined in the ITU Q.920 through Q.923 documents. The third layer 84 (Network layer) is defined in the ITU Q.930 through Q.939 documents. These specifications taken together define how to build the hardward abstraction block 28 for virtual phone support built on top of an ISDN switch.

[0055] Initialization Functions

[0056] The following functions are used for initialization and are typically only called system on startup.

vp_init ( )  Performs general virtual phone
             initialization such as allocating data
             and variable initialization. This
             function is called by the main
             application once during startup.
vp_init_pbx— Performs initialization specific to a
type ( )     particular switch. This function is
             called automatically by the virtual phone
             system when the VPAPI function
             “vp_SetPbxType” is called. Normally,
             this happens only once at startup.
vp_init_set— Performs initialization specific to a
type ( )     specific digital telephone. This
             function is called automatically by the
             virtual phone system when the VPAPI
             function “vp_SetSetType” is called.
             Normally, this happens only once at
             startup.

[0057] Configuration Control Functions

[0058] These functions are used to manage system configuration information between the main application and the virtual phone.

[0059] vp_SendPbxType (BYTE resp)

[0060] vp_GetPbxType (BYTE *type)

[0061] vp_SetPBXType (BYTE type)

[0062] The foregoing three functions configure the virtual phone 20 with the current physically connected type of switch 12. After the main application determines which switch is connected, it calls the Set function. The Set function automatically call vp_init_pbx_type ().

[0063] type One of the following defined variables representing the switch type.

PBX_NONE    No switch connected (default)
PBX_ATT     AT&T switch connected
PBX_M1      Meridian switch connected
PBX_NORSTAR Norstar switch connected
PBX_ROLM    Rolm switch connected

[0064] resp The type of data to be transmitted to the serial port.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0065] vp_SendSetType (BYTE resp)

[0066] vp_GetSetType (BYTE *type)

[0067] vp_SetSetType (BYTE type)

[0068] The foregoing three functions configure the virtual phone 20 with the current physically connected type of digital telephone. After the main application 16 determines which digital phone is connected, it calls the set function. The Set function automatically calls vp_init_set_type ().

[0069] type One of the following defined variables representing the switch type.

SET_NONE        No digital phone connected
                (default)
SET_UNKNOWN     Digital set of unknown type
                connected
SET_ROLM_400    Rolm RP400 set connected
SET_ROLM_240    Rolm RP240 set connected
SET_ROLM_120    Rolm RP120 set connected
SET_ROLM_600    Rolm 600 series set connected
SET_ROLM_300    Rolm 300 series set connected
SET_M1_2616     Meridian 2616 set connected
SET_NOR_7310    Norstar 7310 set connected
SET_NOR_7208    Norstar 7208 set connected
SET_NOR_7100    Norstar 7100 set connected
SET_NOR_7310BLF Norstar 7310 BLF set
                connected
SET_NOR_7324    Norstar 7324 set connected

[0070] resp The type of data to be transmitted to the serial port 26.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0071] vp_SendConnections (BYTE resp)

[0072] vp_GetConnections (BYTE *mask)

[0073] vp_SetConnections (BYTE mask)

[0074] The foregoing three functions configure the virtual phone 20 with a list of physically connected phones. The main application 16 will determine the types of phone units that will have access to the system. Once determined, it calls this functions with a mask representing current connections.

[0075] mask A bit mask used to correspond to up to 8 phone units. If the bit for given phone type is on in the mask, that phone is connected in the system.

PHONE_NONE    No phones connected (default)
PHONE_ADJUNCT The compatible digital phone
              is connected
PHONE_AUX     The serial link based phone
              is connected
PHONE_CS1000  The analog conference phone
              is connected

[0076] resp The type of data to be transmitted to the serial port 26.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0077] Voice MUX Control Functions

[0078] When multiple phones are connected to the system at one time, it is necessary to maintain which of the phones is physically in use. The virtual phone 20 needs this information so that it can direct voice data to the proper phone. Once a phone has “control” of the voice, the virtual phone 20 is responsible for blocking other units from taking dangerous actions (such as terminating the call).

[0079] The key elements the virtual phone 20 is concerned with are the current control, and the last touched unit. These values enable the virtual phone to manage call control seamlessly between connected phone units.

[0080] vp_SendActivePhone (BYTE) resp)

[0081] vp_GetActivePhone (BYTE *type)

[0082] vp_SetActivePhone (BYTE type)

[0083] The foregoing three functions configure the virtual phone 20 with the current active phone 14. A phone is considered active if the voice path is active, and is directed toward that phone. The active phone is also known to be the phone with “control”.

[0084] type The phone type ID of the connected phones that currently has control. The phone type must be in the connections mask list.

PHONE_NONE    Idle, no phones have control
              (default)
PHONE_ADJUNCT The compatible digital phone
              has control
PHONE_AUX     The serial link based phone
              has control
PHONE_CS1000  The analog conference phone
              has control

[0085] resp The type of data to be transmitted to the serial port.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0086] vp_SendTouchedPhone (BYTE resp)

[0087] vp_GetTouchedPhone (BYTE *type)

[0088] vp_SetTouchedPhone (BYTE type)

[0089] The foregoing three functions configure the virtual phone 20 with the last touched phone. When the user presses a button, or goes off hook on a particular phone, it is considered touched. When a call is terminated, no phones are considered touched. The phone to go active will always be the phone with the current touched status.

[0090] type The phone type ID if the connected phones that was last used by the operator. The phone type must be in the connections mask list.

PHONE_NONE    Idle, no phones have control
              (default)
PHONE_ADJUNCT The compatible digital phone
              has control
PHONE_AUX     The serial link based phone
              has control
PHONE_CS1000  The analog conference phone
              has control

[0091] resp The type of data to be transmitted to the serial port.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0092] Voice Control Functions

[0093] The functions are used to manage all voice related information within the virtual phone 20. Voice active status, volume, and physical unit on a phone are all maintained.

[0094] vp_SendVoiceState (BYTE resp)

[0095] vp_GetVoiceLevel (BYTE *level)

[0096] vp_GetVoiceUnit (BYTE *unit)

[0097] vp_GetVoiceVolume (BYTE *volume)

[0098] vp_SetVoiceLevel (BYTE level)

[0099] vp_SetVoiceUnit (BYTE unit)

[0100] vp_SetVoiceVolume(BYTE volume)

[0101] The foregoing seven functions configure the virtual phone 20 with the current voice status. Whenever the switch 12 activates or deactivates the voice path, these functions are called. Some switches and phones have the ability to activate the voice path at different volumes, and on different units (such as headset or speakerphone).

[0102] level When TRUE, the system voce path is active. When FALSE, it's inactive. See vp_GetActivePhone to determine which phone has control of the voice path.

[0103] unit The unit on the phone which is in use by the operator.

VOICE_HANDSET The standard handset found on
              most phones
VOICE_SPEAKER The speaker/microphone (found
              on some phones)
VOICE_HEADSET An auxiliary headset unit
              (usually a separate plug in
              device)

[0104] volume The volume at which voice can be heard through the phone.

VOICE_MUTE   Voice active, but volume
             muted
VOICE_NORMAL Normal voice volume
VOICE_LOW    Volume audible, but lower
             than normal
VOICE_HIGH   Volume higher than normal

[0105] resp The type of data to be transmitted to the serial port.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0106] Ringer Control Functions

[0107] These functions are used to manage all ringer related information within the virtual phone 20. Ringer active status, cadence, and tone during ring are all maintained.

[0108] vp_SendRingerState (BYTE resp)

[0109] vp_GetRingerLevel (BYTE *level)

[0110] vp_SetRingerCadence (BYTE *cadence)

[0111] vp_GetRingerTone (BYTE *tone)

[0112] vp_SetRingerLevel (BYTE level)

[0113] vp_SetRingerCadence (BYTE cadence)

[0114] vp_SetRingerTone (BYTE tone)

[0115] The foregoing seven functions configure the virtual phone 20 with the current ringer status. Whenever the switch 12 turns the audible ringer on or off, these functions are called. Different switches use different ring cadences and ring tones. The virtual phone 20 maintains this information.

[0116] level When TRUE, the ringer is considered active. On some switches, the ringer may be active for the full duration of a ring cycle. In others, it may be active only when the audible ringing sound is heard. When FALSE, the ringer is not active.

[0117] cadence The cadence at which the switch is sending the ring signal.

RINGER_CAD_OFF No ring cadence
RINGER_CAD_ON  Standard ring cadence active
RINGER_CAD_2   Alternate ring cadence active

[0118] Tone The tone at which the ring is heard.

RINGER_TONE_OFF No audible tone
RINGER_TONE_A   Tone A
RINGER_TONE_B   Tone B
RINGER_TONE_C   Tone C
RINGER_TONE_D   Tone D
RINGER_TONE_E   Tone E
RINGER_TONE_F   Tone F
RINGER_TONE_G   Tone G
RINGER_TONE_H   Tone H

[0119] resp The type of data to be transmitted to the serial port.

QUERY_RESPONSE No charge, serial packet is
               due to query
DELAT_RESPONSE The state of the virtual
               phone has changed

[0120] Lamp Control Functions

[0121] These functions are used to manage all lamp (LED or light) related information within the virtual phone 20. Many lamps typically exist on a given system. The virtual phone has the facility to store the state of any of these lamps. It is also possible to pass the lamp update information directly to the host system. In this case, the virtual phone just passes the information through without maintaining it.

[0122] In the case where the lamp is stored in the virtual phone, any of the functions can be used to read or write data. The functions with the “V” in the name require the virtual phone index of the lamp. The remaining functions work directly with the raw ID. The “Ex” of extended functions allow for multiple bytes of raw ID information.

[0123] When the lamp status is not maintained within the virtual phone structures, only the functions working with the raw IDs can be used. These functions will simply pass the update information directly to the host without storing any information within the virtual phone structures.

[0124] vp_SendVLampState (BYTE resp, BYTE vid)

[0125] vp_SendLampState (BYTE resp, BYTE len, BYTE*rawidlist, BYTE state)

[0126] vp_GetVLampState (BYTE vid, BYTE *state)

[0127] vp_SetVLampState (BYTE vid, BYTE state)

[0128] vp_SetLampState (BYTE rawid, BYTE state)

[0129] vp_SetLampState (BYTE len, BYTE *rawidlist, BYTE state)

[0130] rawid The raw ID sent from the switch. The virtual phone checks to see if this lamp is configured as part of the defined phone. If so, a look up is done to get the virtual index (vid) of the correct button/lamp index.

[0131] rawidlist A list of raw IDs sent from the switch. This is used when more than one byte of information is needed to reference the lamp. The “len” parameter is used to define the number of bytes in this list.

[0132] len The number of bytes in the “rawidlist”.

[0133] state The state of the lamp.

LAMP_STATE_OFF     Lamp is dark
LAMP_STATE_ON      Lamp light is on steady
LAMP_STATE_FLASH   Lap is on in a flashing
                   pattern
LAMP_STATE_FLUTTER Lamp is on in a fluttering
                   pattern
LAMP_STATE_WINK    Lamp is on in a winking
                   pattern
LAMP_STATE-FLICKER Lamp is on in a flickering
                   pattern
LAMP_STATE_MISC1   Lamp is on in an unknown
                   pattern

[0134] vid The ID within the virtual phone 20 for the lamp. Each Button/Lamp control structure has fields for lamp information. Only certain buttons/lamps are defined to be as part of the virtual phone 20. This field is an index into the virtual phone's button/lamp structure. (See section Button/Lamp index descriptions)

[0135] resp The type of data to be transmitted to the serial port 26.

QUERY_RESPONSE No change, serial packet is
               due to a query
DELTA_RESPONSE The state of the virtual
               phone has changed

[0136] Button Control Function

[0137] These functions are used to manage all button and hook switch related information within the virtual phone. A hook switch and many buttons typically exist on a given system. The virtual phone has the facility to store the state of any of these buttons. It is also possible to pass the button press/release information directly to the host system. In this case, the virtual phone just passes the information through without maintaining it.

[0138] The hook switch is considered a button and is always defined as button number zero in the virtual phone.

[0139] In the case where the button is stored in the virtual phone, any of the functions can be used to read or write data. The functions with the “V” in the name require the virtual phone index of the button. The remaining functions work directly with the raw ID. The “Ex” of extended functions allow for multiple bytes of raw ID information.

[0140] When the button status is not maintained within the virtual phone structures, only the functions working with the raw IDs can be used. These functions will simply pass the update information directly to the host without storing any information within the virtual phone structures.

[0141] vp_SendVButtonState (BYTE resp, BYTE vid)

[0142] vp_SendButtonState (BYTE resp, BYTE len, BYTE*rawidlist, BYTE state)

[0143] vp_GetVButtonState (BYTE vid, BYTE *state)

[0144] vp_SetVButtonState (BYTE vid, BYTE state)

[0145] vp_SetButtonState (BYTE rawid, BYTE state)

[0146] vp_SetButtonState (BYTE len, BYTE *rawidlist, BYTE state)

[0147] rawid The raw ID sent from the switch. The virtual phone 20 checks to see of this button is configured as part of the defined phone. If so, it is used to reference the correct button/lamp index.

[0148] rawidlist A list of raw IDs sent from the switch. This is used when more than one byte of information is needed to reference the button. The “len” parameter is used to define the number of bytes in this list.

[0149] len The number of bytes in the “rawidlist”.

[0150] state The State of the button or hook switch. Buttons can be either pressed or released. The hook switch is considered pressed when off hook, and released when on hook.

[0151] BUTTON_PRESS Button has been pressed

[0152] BUTTON_RELEASE Button has been released

[0153] vid The ID within the virtual phone 20 for the button or hook switch. Each Button/Lamp control structure has fields for button information. Only certain buttons/lamps are defined to be as part of the virtual phone. This field is an index into the virtual phone's button/lamp structure. (See section Button/Lamp index descriptions).

[0154] resp The type of data to be transmitted to the serial port.

[0155] QUERY_RESPONSE No change, serial packet is due to a query

[0156] DELTA_RESPONSE The state of the virtual phone has changed

[0157] Hook Switch Control Functions

[0158] The hook switch is just a button. Button index zero is always fixed to the hook switch. Because of this, the button API calls can be used for hook switch control. However, for simplication sake, a set of API function are provided for direct hook switch control.

[0159] vp_SendHookState (Byte resp)

[0160] vp_SetHook_State (BYTE state)

[0161] vp_GetHookState (BYTE *state)

[0162] state The state of the book switch.

[0163] HOOK_OFF Off hook (Same as button press)

[0164] Hook_ON On hook (Same as button release)

[0165] resp The type of data to be transmitted to the serial port.

[0166] QUERY_RESPONSE No change, serial packet is due to a query

[0167] DELTA_RESPONSE The state of the virtual phone has changed

[0168] Display Control Functions

[0169] The virtual phone supports the ability to maintain a flexible display. These functions provide the abstraction layer the ability to build the display in a way similar to how the switch puts information on the display.

[0170] The abstraction layer calls the “update” functions to send text changes to the display as they are received from the switch. Addressing is either direct (by row and column number), or based on a cursor position. The switch often clears single rows or even the entire display with one command. An API function exists for each of these tasks.

[0171] Often, more than one cursor exists for a given display. The abstraction layer passes the cursor index whenever a display update at cursor type command is given. An API command exists to maintain each current cursor position.

[0172] When the display has been stable (has not changed) for a given period of time, or the switch sends a “display stable” command, the abstraction layer calls the “vp_dDisplayIsStable” function. This triggers the virtual phone to send the display contents to the host.

[0173] vp_SendDisplay (BYTE resp)

[0174] vp_dDisplayIsStable()

[0175] vp_dClearDisplay()

[0176] vp_dClearRow (BYTE row)

[0177] vp_dSetCursor Position (BYTE cindex, BYTE row, BYTE col)

[0178] vp_dUpdateCharAtCursor (BYTE cindex, BYTE ch)

[0179] vp_dUpdateCharAtCursor (BYTE cindex, BYTE *txt, BYTE len)

[0180] vp_dUpdateCharAbsolute (BYTE row, BYTE col, BYTE ch)

[0181] vp_dUpdateTextAbsolute (BYTE row, BYTE col, BYTE *txt, BYTE len)

cindex The index of the cursor to be used to
       execute the function. This index is
       maintained separately and contains a row and
       column of where the text will be displayed.
row    The row number on which the text will be
       displayed.
col    The column number on which the text will be
       displayed.
resp   The type of data to be transmitted to the
       serial port.
       QUERY_RESPONSE No change, serial packet is
       due to a query
       DELTA_RESPONSE the state of the virtual
       phone has changed
ch     The ASCII character to be displayed.
txt    The ASCII text string to be displayed.
len    The number of characters in the ASCII text
       string to be displayed.

[0182] Carrier Control Functions

[0183] The virtual phone maintains the carrier state of the switch, and the adjunct digital phone. This information is available via the following functions.

[0184] vp_SendCarrier (BYTE resp, BYTE device)

[0185] vp_SetCarrier (BYTE device, BYTE level)

[0186] vp_GetCarrier (BYTE device, BYTE *level)

[0187] device The physical device.

[0188] CARRIER_DEVICE_SWITCH The switch

[0189] CARRIER_DEVICE_ADJUNCT The adjunct digital phone

[0190] level The carrier level

[0191] CARRIER_LEVEL_LOSS No carrier for the device

[0192] CARRIER_LEVEL_GAIN The device has carrier

[0193] cARRIER_LEVEL_UNKNOWN Carrier state unknown

[0194] resp The type of data to be transmitted to the serial port.

[0195] QUERY_RESPONSE No change, serial packet is due to a query

[0196] DELTA_RESPONSE The state of the virtual phone has changed

[0197] Pass Through Control Functions

[0198] It is possible to block certain types of messages between the switch and the digital phone. The pass through flags set which messages are allowed to pass through, and which are blocked. The following APIs provide this functionality.

[0199] vp_SendPAssThroughFlags (BYTE resp)

[0200] vp_SetPassThroughFlags (BYTE flags)

[0201] vp_GetPassThroughFlags (BYTE *flags)

[0202] flags A bit mask with each bit representing a different pass through mode. If the bit is set, the message is allowed to pass. If cleared, the message is blocked.

PASS_HOOK    hook switch from digital set
PASS_BUTTON  button presses/releases from
             digital set
PASS_LAMP    lamp updates from switch
PASS_DISPLAY display updates from switch
PASS_RINGER  ringer updates from switch

[0203] resp The type of data to be transmitted to the serial port.

[0204] QUERY_RESPONSE No change, serial packet is due to a query

[0205] DELTA_RESPONSE The state of the virtual phone has changed

[0206] Bearer Channel Control Functions

[0207] The voice and data channels can be routed normally to the adjunct digital phone, or to another device. These functions control the routing of these bearer channels. The system may want to instruct the virtual phone to send voice or data information to a unit other than the adjunct phone such as a conference phone or a DSP for processing.

[0208] Since the digital data link between the switch and the phone typically provides a voice channel and at least one data channel, these functions use a bit mask to identify which of the channels to control.

[0209] vp_SendVoiceMux (BYTE resp)

[0210] vp_SetVoiceMux (BYTE devicemask, BYTE unit)

[0211] vp_GetVoiceMux (BYTE devicemask, BYTE*unit)

[0212] devicemask A bit mask with each bit representing one of the bearer channels to direct with the command

VMUX_VOICE voice channel
VMUX_DATA  data channel
VMUX_DATA1 primary data channel
VMUX_DATA2 secondary data channel

[0213] unit The device where the channel is to be directed.

[0214] VMUX_ADJUNCT Adjust digital telephone

[0215] VMUX_AUX The other connected unit (DSP, conference phone, etc.)

[0216] resp The type of data to be transmitted to the serial port.

[0217] QUERY_RESPONSE No change, serial packet is due to a query

[0218] DELTA_RESPONSE The State of the virtual phone has changed

[0219] Virtual Phone Host Interface Protocol

[0220] Communications between the virtual phone 20 and the external device, i.e. host system, is accomplished via an internally designed custom protocol called the Virtual Phone Host Interface Protocol (VPHIP) 26. Any time the virtual phone changes, a VPHIP packet is sent out to the host reflecting the update to the virtual phone structure. This keeps the auxiliary PC 16 up to date at all times with the current status of the virtual phone.

[0221] The auxiliary PC 16 also has the ability to manipulate the virtual phone by sending VPHIP packets across the link. The virtual phone parses the VPHIP packet and calls the apropriate VPAPI function, which in turn may update the virtual phone structure.

[0222] The functionality and structure of VPHIP is described follows:

[0223] Packet Format

[0224] All packets adhere to the following format:

	Length	Description	Value
	1 Byte	Header	see note
	1 Byte	Packet Length	variable
	1 Byte	Packet Description	see below sections
	Variable	Packet Data	see below sections

[0225] The header byte follows specific rules. Any message originating from the switch 12 has a header of 0×01. Messages from the adjunct phone 14 have header 0×02. Messages from the auxiliary PC 16 have header 0×04. Informational messages (such as PBX type) have header 0×00. Queries, and responses to queries turn on the upper most bit of the header which result in header codes of 0×08, 0×81 and 0×82.

[0226] System Information messages

[0227] System information packets are used to communicate phone status information between the internal virtual phone 20 and the auxiliary PC 16. All system information packets have a header value of 0×00.

[0228] Carrier State

[0229] These packet types are used to identify the carrier condition of the switch or the digital telephone.

	Byte	Description	Value
	0	Header	0x00
	1	Packet Length	4
	2	Carrier (Switch)	0xB0
	3	Carrier Level
		No Carrier	0
		Carrier	1
		Unknown	2
		Condition
	0	Header	0x00
	1	Packet Length	4
	2	Carrier (Digital	0xB1
		Set)
	3	Carrier Level
		No Carrier	0
		Carrier	1
		Unknown	2
		Condition

[0230] Adjunct Phone Type

[0231] The adjunct phone type packet is used to identify the type of digital phone (if any) that is physically connected to the interface board.

	Byte	Description	Value
	0	Header	0x00
	1	Packet Length	4
	2	Adjunct Phone Type	0xF1
	3	Phone Index
		None	0
		Unknown	1
		Rolm RP400	10
		Rolm RP240	11
		Rolm RP120	12
		Rolm RP300	13
		Rolm RP300	14
		M1 2616	30
		Norstar 7310	50
		Norstar 7208	51
		Norstar 7100	52
		Norstar 7310 BLF	53
		Norstar 7324	54
		AT&T 7405	70
		AT&T 7406	71
		AT&T 7407	72
		AT&T 7434	73

[0232] Current Active Phone

[0233] When more than one phone is connected to the interface board at the same time, it is often necessary to know which unit is actively communicating with the switch 12. This is necessary to establish such things as voice routing, and button filtering. This packet returns the physical phone description that is currently active.

	Byte	Description	Value
	0	Header	0x00
	1	Packet Length	4
	2	Active Phone Type	0xF2
	3	Unit Index
		None	0x00
		Adjunct Digital Set	0x01
		Auxiliary	0x02
		Conference Phone	0x04
		future use	0x08 . . .

[0234] Last Touched Phone

[0235] When more than one phone is connected to the interface board at the same time, the user may operate either unit to make and receive calls. Knowing which physical unit was last touched enables the virtual phone 20 to route voice and control to the appropriate unit.

	Byte	Description	Value
	0	Header	0x00
	1	Packet Length	4
	2	Touched Phone Type	0xF3
	3	Unit Index
		None	0x00
		Adjunct Digital Set	0x01
		Auxiliary	0x02
		Conference Phone	0x04
		future use	0x08 . . .

[0236] Physical Connections

[0237] The virtual phone 20 may support several controlling and/or monitoring devices simultaneously. This command is used to transfer the current configuration information. The connection information is stored as a bit mask providing space for up to 8 physical devices.

	Byte	Description	Value
	0	Header	0x00
	1	Packet Length	4
	2	Physical Cncts Type	0xF4
	3	Connection Mask
		None	0x00
		Adjunct Digital Set	0x01
		Auxiliary	0x02
		Conference Phone	0x04
		future use	0x08 . . .

[0238] Messages from the switch

[0239] All messages originating from the switch 12 have a of 0×01.

[0240] Voice Status

[0241] The Voice Status packets are used to supply the current voice status to the auxiliary PC 16. The physical unit being used, and the volume are also supplied.

	Byte	Description	Value
	0	Header	0x01
	1	Packet Length	5
	2	Voice Enable	0x10
	3	Unit
		Handset	0x01
		Speaker	0x02
		Headset	0x04
	4	Volume
		Mute	0
		Normal	1
		Low	2
		High	3

[0242]

	Byte	Description	Value
	0	Header	0x01
	1	Packet Length	3
	2	Voice Disable	0x11

[0243] The Voice Enable command (0×10) explicitly activates the voice channel regardless of unit state. Voice Disable (0×11) explicitly de-activates voice. The Voice Status command (0×12) is a combination of the two where the presence of a bit in the unit mask is used to determine whether or not voice is active.

	Byte	Description	Value
	0	Header	0x01
	1	Packet Length	5
	2	Voice Status	0x12
	3	Unit
		Handset	0x01
		Speaker	0x02
		Headset	0x04
	4	Volume
		Mute	0
		Normal	1
		Low	2
		High	3

[0244] Ringer Status

[0245] The ringer status packets are used to supply ringer status to the auxiliary PC 16. In addition to ringer status, the cadence and ring tone are also supplied. In some switches, the ringer turns on and off with the audible sound while the calling party is attempting to connect. It may be beneficial to leave the ringer in the “on” state and have the virtual phone use the “cadence off” condition between audible rings. This will give feedback similar to that of using the LED for incoming call status.

	Byte	Description	Value
	0	Header	0x01
	1	Packet Length	5
	2	Ringer Active	0x20
	3	Cadence
		Off	0
		On	1
		#2	2
	4	Tone
		Off	1
		A	2
		B	3
		C	4
		D	5
		E	6
		F	7
		G	3
		H	9

[0246]

	Byte	Description	Value
	0	Header	0x01
	1	Packet Length	3
	2	Ringer Inactive	0x21

[0247] Lamp Status (Generic)

[0248] The Lamp status packet is used to supply lamp (LED) information to the Auxiliary PC 16. The internal virtual phone lamp ID (not the switch's raw ID), and the flash rate are passed in the packet.

Byte	Description	Value
0	Header	0 × 01
1	Packet Length	5
2	Lamp Update	0 × 30
3	Flash Rate
	Off	1
	On	2
	Flash	3
	Flutter	4
	Wink	5
	Flicker	6
	Misc1	7
4	Lamp ID
	Prime Line	16
	Others	17

[0249] Lamp Status (Raw)

[0250] The Raw lamp status packet is used to supply lamp (LED) information to the auxiliary PC. The raw ID received from the switch (not the internal virtual phone ID), and the flash rate are passed in this packet.

[0251] In the case where lamps have multiple bytes for the ID, the additional bytes are placed at the end of the packet and the length is changed accordingly.

Byte	Description	Value
0	Header	0 × 01
1	Packet Length	4 + number of
		raw ID bytes
2	Lamp Update (Raw)	0 × 31
3	Flash Rate
	Off	1
	On	2
	Flash	3
	Flutter	4
	Wink	5
	Flicker	6
	Misc1	7
4	Lamp raw ID byte #1
5	[Lamp raw ID byte #2]

[0252] Display Status

[0253] The Display status packets are used to supply display information to the auxiliary PC. These packets allow for portions of the display to be updated as they are received from the switch. The basis display packet supplies text and position information (the length can be extracted from the packet length byte). There are other special packets that can be used for scrolling of flashing characters on the auxiliary PC.

	Byte	Description	Value
	0	Header	0 × 01
	1	Packet Length	5 + (length of text)
	2	Display Update	0 × 40
	3	Row	variable
	4	Column	variable
	5 . . .	Text	“variable string”

[0254] The Clear Display packet can also be used to clear the entire display, or a single row of the display.

Byte	Description	Value
0	Header	0 × 01
1	Packet Length	4
2	Clear Display	0 × 41
3	Row
	All rows	0
	Single row	row number

[0255] Messages from the Phone

[0256] All messages originating from the PBX 12 have a header value of 0×02.

[0257] Button Status (Generic)

[0258] The virtual phone 20 is configured with a set of generic buttons used across all switches. These buttons (and associated lamps, if any), have fixed identifiers. Only the buttons with identifiers assigned to the virtual phone function with this command.

[0259] The Button status packets are used to supply button press/release information originating from the adjunct phone to the auxiliary PC.

Byte	Description	Value
0	Header	0 × 02
1	Packet Length	4
2	Button Press	0 × 50
	(Generic)
3	ID
	Hook Switch	0 (OFF hook)
	Hold	1
	Transfer	2
	Release	3
	Key Pad (0-9, *, #)	4-15
	Prime Line	16
	Others	17

[0260]

Byte	Description	Value
0	Header	0 × 02
1	Packet Length	4
2	Button Press	0 × 51
	(Generic)
3	ID
	Hook Switch	0 (ON hook)
	Hold	1
	Transfer	2
	Release	3
	Key Pad (0-9, *, #)	4-15
	Prime Line	16
	Others	17 . . .

[0261] Button Status (Raw)

[0262] All buttons on all phones have a defined raw id. This command is used to transmit this raw id across the interface. Either this command, or the Generic button status command can be used to transmit button state changes.

[0263] In the case where buttons have multiple bytes for the ID, the additional bytes are placed at the end of the packet and the length is changed accordingly.

[0264] The Button status packets are used to supply button press/release information originating from the adjunct phone to the auxiliary PC.

Byte	Description	Value
0	Header	0 × 02
1	Packet Length	3 + # of bytes in raw ID
2	Button Press (Raw)	0 × 52
3	Raw ID byte #1
4	[Raw ID byte #2]

[0265]

Byte	Description	Value
0	Header	0 × 02
1	Packet Length	3 + # of bytes in raw ID
2	Button Release	0 × 53
	(Raw)
3	Raw ID byte #1
4	[Raw ID byte #2]

[0266] Hook Switch Status

[0267] The virtual phone contains a single hook switch which represents the state of the physical hook switch on the phone. A packet is sent when the state of the hook switch changes.

Byte	Description	Value
0	Header	0 × 02
1	Packet Length	3
2	Hook Switch Up	0 × 54
0	Header	0 × 02
1	Packet Length	3
2	Hook Switch Down	0 × 55

[0268] Messages from the Auxiliary PC (Host)

[0269] All messages originating from the auxiliary PC 16 have a header value of 0×04. In many cases, the host 16 may emulate commands from the switch or the digital telephone. Any of the previously defined packets may be sent from the host. The header signs the virtual phone as to the source of the command so the appropriate action may be taken.

[0270] Button Control and Status

[0271] The virtual phone 20 is configured with a set of generic buttons used across all switches. These buttons (and associated lamps, if any), have fixed identifiers. Only the buttons with identifiers assigned to the virtual phone function with this command.

[0272] The auxiliary PC 16 uses the button control and status packets to transmit button change requests to the virtual phone. The effect of these packets on the virtual phone 20 is the same as if buttons were pressed on the adjunct phone directly. This protocol allows for auxiliary button press/release emulation.

[0273] Regardless if button changes originate on the adjunct phone or the auxiliary PC 16, the virtual phone 20 maintains the current button state. Whenever a button state changes, these same packets are used to transmit the new status to the auxiliary PC 16.

[0274] System State

[0275] When the host system is ready to receive messages from the virtual phone, it sends the enable command. This causes the virtual phone to send all virtual phone changes and system messages to the host via the host interface protocol. When the host is disabled, the virtual phone still maintains the state phone state, it just blocks the information from being transmitted to the host.

Byte	Description	Value
0	Header	0 × 04
1	Packet Length	4
2	System State	0 × 90
3	Level
	Disabled	0
	Enabled	1

[0276] Pass Through Flags

[0277] The host system has the ability to request certain types of messages to be passed or blocked between the switch and the digital telephone. It is the responsibility of the virtual phone to maintain these flags and send only the specified packets between the units.

[0278] If the bit in the mask is set, the packet types are passed through. If cleared, they are blocked.

	Byte	Description	Value
	0	Header	0 × 04
	1	Packet Length	4
	2	Hook Switch Up	0 × 91
	3	Flags
		Hook Switch	0 × 01
		from Set
		Buttons from	0 × 02
		Set
		Lamp updates	0 × 04
		from switch
		Display from	0 × 08
		Switch
		Ringer from	0 × 10
		Switch

[0279] Dial Command

[0280] The host can request the virtual phone to dial a given string of digits. The virtual phone implements the button presses/releases and the necessary delays based on the parameters to the dial command. The dial string can contain any of the keypad buttons and the comma. The keypad buttons represent themselves and the commas represents a specified delay.

[0281] The digital duration (byte 3) of the command represents the length in milliseconds that the key is to be held down. The inter-digit duration is the length between key presses. The pause duration is the length of the pause (comma) character.

[0282] When the virtual phone completes the dialing, it sends a 3 byte version of this packet back to the host with only the header, length, and commands bytes.

	Byte	Description	Value
	0	Header	0 × 04
	1	Packet Length	6 + # of digits
			in dial string
	2	Dial Command	0 × 93
	3	Digit Duration
	4	Inter-Digit
		duration
	5	Pause Duration
	6	Dial string

[0283] Bearer Channel Direction

[0284] Either the abstraction layer or the host system has the ability to direct the voice mux to their desired device. This device is typically either the adjunct digital phone, or an auxiliary unit. The virtual phone maintains the direction of the voice mux. In addition to voice, a number of additional channels can be controlled. This command is used to transfer mux direction status of all the bearer channels.

[0285] If the bit in the mask is set, the mux is directed to the auxiliary unit. If cleared, the channel is directed to the adjunct digital telephone.

	Byte	Description	Value
	0	Header	0 × 04
	1	Packet Length	4
	2	Voice Mux	0 × 93
	3	Device Mask
		Voice	0 × 01
		Data	0 × 02
		Data1	0 × 02
		Data2	0 × 04

[0286] Queries

[0287] The auxiliary PC 16 can query the virtual phone 20 for current status at any time. This is done by sending a command symmetric to the receive command for each status type. These commands are the same as the receive commands with the exception of the upper most bit of the header byte. When this bit is high, the virtual phone interprets this as a query and automatically responds with the current status.

[0288] For example, if the auxiliary PC 16 is requesting the ringer status, it sends the packet [81 04 20##] (where ## is irrelevant data). The virtual phone 20 will respond by transmitting [01 04 20##] or [01 04 21] (where ## is valid data) back to the auxiliary PC.

[0289] The valid query command IDs are:

[0290] 0×54 Query Hook Switch Status

[0291] 0×91 Query Pass Through Flags Status

[0292] 0×B0 Query Switch Carrier Status

[0293] 0×B1 Query Digital Phone Carrier Status

[0294] 0×10 Query Voice Status

[0295] 0×20 Query Ringer Status

[0296]

[0297] 0 ×30 Query Lamp Status

[0298] 0×40 Query Display Status

[0299] 0×50 Query Button Status

[0300] 0×F0 Query Switch Type

[0301] 0×F1 Query Adjunct Phone Type

[0302] 0×F2 Query Current Active Phone

[0303] 0×F3 Query Last Touched Phone

[0304] In connection with the foregoing description, Table I lists the data structures of virtual phone 20 and Table II lists various serial commands.

TABLE I
Virtual Phone Structures
typedef struct /*Virtual Phone Voice
{              Structure*/
               BYTE active;           /*1 = active 0 = not active*/
               BYTE unit;             /*mask active unit UPV_???? */
               BYTE volume;           /*voice mute, low, high, etc
                                      */
{VP_VOICE;
typedef struct /*Virtual Phone Ringer
               Structure*/
               BYTE active;           /*1-active0-not active*/
               BYTE cadence;          /*list of current cadence
                                      type*/
               BYTE tone;             /*list of current tone type*/
{VP_RINGER;
typedef struct /*virtual phone display
               structure*/
               BYTE row;              /*Current row for this
                                      cursor*/
               BYTE col;              /*Current column for this
               cursor*/
}VP_CURSOR:
typedef struct /*Virtual Phone Display
               Structure*/
{VP_CURSOR;
typedef struct /*Virtual Phone Display
               Structure*/
               BYTE grid [VPD_MAX     /*The display text*/
               ROWS] [VPD_MAXCOLS];
               BYTE cursor            /*current cursors*/
               {VPD_MAXROWS};
               BYTE NumRows;          /*Number of Rows on this
                                      page*/
               BYTE NumColumns        /*Number of Columns on this
                                      page*/
               BYTE NumCursors;       /*Number of available
                                      cursors*/
               BYTE IsStable;         /*True if the display has
                                      stablized*/
               BYTE IsClear;          /*True if the display is
                                      currently clear*/
{VP_DISPLAY;
typedef struct /*Virtual Phone Button/Lamp
               Structure*/
               BYTE deviceMask;       /*mask showing which of next 4
                                      are valid*/
               BYTE pressID;          /*ID of button press info*/
               BYTE releaseID;        /*ID of button release info*/
               BYTE lamp1ID;          /*ID of first lamp info*/
               BYTE lamp2ID;          /*ID of second lamp info*/
               BYTE buttonState;      /*state of button; 1 = down 0-
                                      up*/
               BYTE lamp1State;       /*state of first lamp*/
               BYTE lamp2State;       /*state of second lamp*/
{VP_BUTTON;
typedef struct /*Main Virtual Phone
               Structure*/
{
               VP_VOICE voice;        /*voice status*/
               VP_RINGER ringer;      /*ringer status*/
               VP_DISPLAY display;    /*LCD display status*/
               BYTE Hook Switch       /*Hook switch status*/
               BYTE num_buttons;      /*number of buttons actually
                                      in use*/
               VP_BUTTON button       /*button/lamp status*/
               [VP_MAXBUTS];
               BYTE StandAlone;       /*Operate without Digital
                                      set*/
               BYTE SwitchType;       /*Type of switch connected*/
               BYTE DigSetType;       /*Type of configured digital
                                      SET, if any
               BYTE Connections;      /*Which Phone Units are
                                      physically connected*/
               BYTE ActivePhone;      /*Which Physical Phone Unit is
                                      active
               BYTE TouchedPhone;     /*Which Physical Phone Unit
                                      was touched
               BYTE Carrier(2);       /*0 = switch 1 = digital set*/
               BYTE PassThroughFlags; /*event block flags*/
               BYTE VoiceMux;         /*Bearer channel direction*/
{VIRTUAL_PHONE;

[0305]

TABLE II
Brief Host Command List
De-
scrip-			Com-
tion	Header	Length	mand	Data1	Data2	Data3
Voice	P	05	10	Unit
Enable
Voice	P	03	11			Volume
Disable
Voice	P	05	12	Unit		Volume
State
Ringer	P	05	20	Cadence	Tone
Enable
Ringer	P	03	21
Disable
Lamp	P	05	30	status
(Gen-
eric)
Lamp	P	04 + cou	31	status	41 ID	[raw
(Raw)		nt			#1	ID#2]
Display	P	05 + txt	40	row	col	text . . .
		len
Display	P	03	41
Clear
Button	SHX	04	50
Press
(Gen)
Button	SHX	SHX	04	51ID
Release
(Gen)
Button	SHX	03 + cou	52	raw ID	[raw
Press		nt		#1	ID
(Raw)					#2 . . . ]
Button		SHX	03 +	53 raw	[raw
Release			count	ID #1	ID #2]
(Raw)
Hook	SHX	03	54
Switch
Up
Hook	SHX	03	55
Switch
Down
System	HX	04	90	Level
State
Pass	HX	04	91	Flags
Through
Flags
Dial	HX	09 = dig	92	see
Command		its		note 1
Bearer	HX	04	93	Device
Channel				mask
Ct1
Carrier	X	04	B0	Level
state -
PBX
Carrier	X	04	B1	Level
State -
SET
PBX	X	04	F0	type
type
SET	X	04	F1	type
type
Active	X	04	F2	unit
Phone
Touched	X	04	F3	unit
Phone
Physical	X	04	F4	mask
Cncts
P-PPBX generated message
S-SET generated message
H-Host generated message
X-Firmware system generated message
note 1: parameters for dial command
data1: digit duration (high byte)
data2: digit duration (low byte)
data3: inter-digit duration (high byte)
data4: inter-digit curation (low byte)
data5: pause duration (high byte)
data6: pause duration (low byte)
data7: ? dial string

[0306] The system of the present invention can be generalized in the form of the system of FIG. 5 including media control proxy 100, communication switch 102 and communication device or terminal 104. Switch 102 is analogous to PBX 12 in FIG. 1, terminal 104 is analogous to phone 14 in FIG. 1 and media control proxy 100 is a generalized form of the virtual phone 18 of FIG. 1. The Media Control Proxy (MCP) 100 is used as a gateway between some communications switching system, i.e. switch 102, and some terminal, i.e. terminal 104. The main purpose of the MCP is to bridge any gap in the communication protocols between the server device (the switch) 102 and the client (the terminal 104).

[0307] Communication device 104 is any device which originates and/or receives a media including audio and visual, and device 104 can be a physical terminal or an emulation of a physical terminal in computer hardware including an application residing in a system.

[0308] In the minimum configuration of FIG. 5, the MCP 100 resides between the switch 102 and the terminal 104. Bearer channel data (voice, video, etc) is passed through by the MCP 100 on channels 110 and 112. The information on the control channels 114 and 116 is processed and converted to a protocol understood by the terminal 104. Depending on the type of terminal connected, this could be a proprietary protocol specific to the terminal, or it could be the MCP's standard protocol designed to communicate with a wide range of devices. Control channel 116 also may be viewed as an application program interface (API).

[0309] The MCP 100 interprets the information it receives from the control channel 114 of the switch 102 and maintains the state of the terminal 104 as defined by the switch 102. As far as the switch 102 is concerned, the MCP 100 is the terminal 104. The MCP 100 also transmits data on the control channel 114 to the switch 102. It does this in the protocols native to the switch 102. The switch 102 interprets any messages coming from the MCP 100 as those coming from the terminal 104.

[0310] The MCP 100 can be configured to function in many different ways. The main point is that it has the ability to communicate with not only the native terminal for the switch, but that it can communicate with an unlimited selection of terminals or communications devices. The fixed (and sometimes proprietary) control protocol used in the original connection between the switch and native terminal is converted to whatever communications method is necessary to support any given terminal.

[0311] The type of terminal that may be connected to the MCP 100 is so flexible that the type of medium in which the date and control channels reside is also limitless. A direct proprietary connection is possible, as is a connection over a computer bus. It is also possible to route data and control channel information across new or existing networks. Means of wireless communications is supported. In fact, this system is set up to be configurable to operate with any terminal in whichever transport is desired. The MCP 100 handles the data preparation for any such configuration.

[0312] It is therefore apparent that the present invention accomplishes its intended objects. A telephone communication system is provided which converts proprietary PBX or external application protocols into a common format and thus functions as a protocol interpreter between proprietary switching system protocols and the protocols of various applications. The virtual phone generic interface of the present invention is configurable and works independently of a specific type of integration and provides a common interface between any of the digital phone switches and any number of end devices. Changes in the virtual phone interface are communicated to an external processor which, in turn, can command changes in the virtual phone interface.

[0313] While an embodiment of the present invention has been described in detail, that is done for purposes of illustration, not limitation.

Claims

1. In a communication system comprising at least one telephone switch and at least one communication device: means for providing a virtual phone generic configurable interface serving as a protocol interpreter of the protocol of said telephone switch thereby enabling communication between said switch and said communication device.

2. A system according to claim 1, wherein said means for providing a virtual phone generic configurable interface comprises means for providing a set of virtual phone data structures for representing the state of a phone as known to the telephone switch at any given time.

3. A system according to claim 1, wherein said means for providing a virtual phone generic configurable interface comprises means for providing a virtual phone application program interface for providing data communication between said telephone switch and said communication device.

4. A system according to claim 1, wherein said means for providing a virtual phone generic configurable interface comprises means for providing a communications protocol for the transfer of phone control information between said telephone switch and said communication device.

5. A system according to claim 1, wherein said means for providing a virtual phone generic configurable interface comprises: a) means for providing a set of virtual phone data structures for representing the state of a phone as known to the telephone switch at any given time; and b) means for providing a program interface for accessing said data structures.

6. A system according to claim 5, wherein said means for providing a program interface for accessing said data structures comprises a virtual phone application program interface for providing data communication between said set of virtual phone data structures and said switch and said communication device.

7. In a telephone communication system comprising at least one telephone switch, at least one telephone and a computer for processing applications related to the operation of said telephone switch and said telephone: means for providing a virtual phone generic configurable interface serving as a protocol interpreter between protocols of said telephone switch and protocols of said applications.

8. A system according to claim 7, wherein said means for providing a virtual phone generic interface comprises: a) an internal virtual phone application program interface for providing data communication between said set of virtual phone data structures and said telephone switch and said telephone; and b) means for providing a program interface for accessing said data structures; and c) means for providing a protocol for accessing said data structures; and

9. A system according to claim 8, wherein said means for providing a program interface for accessing said data structures comprises: a) an internal virtual phone application program interface for providing data communication between said set of virtual phone data structures and said telephone switch and said telephone; and b) an external virtual phone application program interface for providing data communication between said external virtual phone application program interface and said computer.

10. A system according to claim 9, further including a communications protocol for providing communication between said external virtual phone application program interface and said computer.

11. In a telephone communication system comprising at least one telephone switch, at least one telephone and an external application device, a virtual phone interface comprising: a) means for providing a set of virtual phone data structures for representing the state of a phone as known to the telephone switch at any given time; b) means for providing a set of symmetric functions for transferring data between said virtual phone data structures and said telephone switch and said telephone and between said virtual phone data structures and communications medium associated with said external application device, said set of functions being the sole means by which said virtual phone data structures are changed: c) means for providing communication between said set of symmetric functions and said telephone switch and said telephone; and d) means for providing communication between said set of functions and said communications medium associated with said external application device.

12. A virtual phone interface according to claim 11, wherein said external application device comprises a computer.

13. A virtual phone interface according to claim 7, wherein said means for providing a set of symmetric functions comprises: a) an internal virtual phone application program interface for providing data communication between said set of virtual phone data structures and said telephone switch and said telephone; and b) an external virtual phone application program interface for providing data communication between said set of virtual phone data structures and said external application device.

14. A virtual phone interface according to claim 13, further including a communications medium for providing communication between said external virtual phone application program interface and said external application device.

15. A method for providing communication in a system comprising at least one telephone switch and at least one communication device, said method comprising the steps of: a) providing a virtual phone generic configurable interface to serve as a protocol interpreter of the protocol of said telephone switch; and b) utilizing said virtual phone generic configurable interface to enable communication between said telephone switch and said communication switch; and

16. A method according to claim 15, wherein said step of providing a virtual phone generic configurable interface comprises providing a set of virtual phone data structures for representing the state of a phone as known to the telephone switch at any given time.

17. A method according to claim 15, wherein said step of providing a virtual telephone generic configurable interface comprises providing a virtual phone application program interface for providing data communication between said telephone switch and said communication device.

18. A method according to claim 15, wherein said step of providing a virtual phone generic configurable interface comprises: a) providing a set of virtual phone data structures for representing the state of a phone as known to the telephone switch at any given time; and b) providing a program interface for accessing said structures.

19. A method according to claim 18, wherein said step of providing a program interface for accessing said data structures comprises providing a virtual phone application program interface for providing data communication between said set of virtual phone data structures and said switch and said communication device.

20. A method for representing features of any type of one or more digital telephones independent of the type of telephone switch operatively associated with said one or more telephones and independent of the number of features in said one or more telephones comprising the steps of: a) providing a set of virtual phone data structures representing the state of said one or more telephones at any given time; b) providing an external device generating applications related to operation of said telephone switch and said one or more telephones; and c) changing said data structures in response to commands issued by said external device.

21. A method according to claim 20, further including changing said data structures in response to events in said telephone switch and in said one or more telephones.

22. A method according to claim 21, further including providing a set of symmetric functions with issue function calls for accessing said data structures from said external device and from said telephone switch and said one or more telephones.

23. A method according to claim 20, wherein said step of changing said data structures in response to commands issued by said external device comprises: a) receiving a command from said external device; b) calling a symmetric function in response to said command to provide a function call; c) converting the function call to a command format in accordance with a specific virtual phone integration to change one or more of said data structures; and d) passing said command format to said telephone switch.

24. A method according to claim 21, wherein said step of changing said data structures in response to events in said telephone switch comprises: a) receiving a packet from said telephone switch; b) utilizing data in said packet to call a symmetric function; c) updating one or more of said data structures by means of a function call issued by said symmetric function; and d) passing information on said updating to said external device.

25. A method for representing features of any type of one or more digital telephones independent of the type of telephone switch operatively associated with said one or more telephones and independent of the number of features in said one or more telephones comprising the steps of: a) providing a set of virtual phone data structures representing the state of the digital telephone as known to the telephone switch at any given time; b) providing an external processor for generating applications related to operations of said telephone switch and said one or more telephones; c) changing said data structures in response to events in said telephone switch and in said one or more telephones; and d) changing said data structures in response to commands issued by said processor related to said applications.

26. A method according to claim 25, further comprising: a) transferring information to said external processor relating to changes in said data structures in response to events in said telephone switch and in said one or more telephones; and b) transferring information to said telephone switch relating to changes in said data structures in response to commands issued by said processes.

27. A method according to claim 25, further including providing a set of symmetric functions which issue function calls for accessing said data structures from said external processor and from said telephone switch and said one or more telephones.

28. A method according to claim 27, wherein said data structures can be changed only via said set of symmetric functions.

29. In a communication system comprising at least one communication switch and at least one communication device: a media control proxy serving as a gateway between said communication switch and said communication device to bridge any gap in communication protocols between said communication switch and said communication device thereby enabling communication between said communication switch and said communication device.

30. A system according to claim 29, wherein said media control proxy includes means for converting a fixed control protocol of an original connection between said communication switch and said communication device to a communications method for supporting any given communication device.

31. A system according to claim 29, wherein a first data bearer channel and a first control channel each are connected to said communication switch and to said media control proxy and a second data bearer channel and a second control channel are connected to said media control proxy and to said communication device.

32. A system according to claim 31, wherein said media control proxy includes means for passing through data on said first and second data bearer channels.

33. A system according to claim 31, wherein said media control proxy includes means for processing information on said first and second control channels for conversion to a protocol understood by said communications device.

34. A method for providing communication in a system comprising at least one communication switch and at least one communication device, said method comprising the steps of: a) providing a media control proxy to serve as a gateway between said communication switch and said communication device to bridge any gap in communication protocols between said communication switch and said communication device; and b) utilizing said media control proxy to enable communication between said communication switch and said communication device.

35. A method according to claim 34, wherein said step of providing a media control proxy comprises connecting a fixed control protocol of an original connection between said communication switch and said communication device to a communications method for supporting any given communication device.

36. A method according to claim 34, wherein said step of providing a media control proxy comprises passing through bearer channel data between said communication switch and said communication device.

37. A method according to claim 34, wherein said step of providing a media control proxy comprises processing control information from said communication switch for conversion to a protocol understood by said communication device.

38. A method according to claim 34, wherein said step of providing a media control proxy comprises interpreting control information received from said communication switch and maintaining the state of the communication device as defined by the communication switch.

39. A method according to claim 34, wherein said step of providing a media control proxy comprises transmitting data to said communication switch on a control channel between said media control proxy and said communication switch in a protocol native to said communication switch so that said communication switch interprets a message from said media control proxy as a message from said communication device.

40. A computer readable memory device encoded with a data structure for providing a virtual phone generic configurable interface serving as a protocol interpreter of the protocol of a telephone switch thereby enabling communication between said switch and a communication device, the data structure having entries wherein each entry contains a representation of the state of the communication device as known to the telephone switch at any given time.