Media dependent module interface for computer-based conferencing system

• US 5,493,568 A
• Filed: 03/13/1995
• Issued: 02/20/1996
• Est. Priority Date: 11/24/1993
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Rajamani, Krishnan, Danneels, Gunner, Sampat, Ketan
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US08/403,226
• Time in Patent Office: 344 Days
• Field of Search: 370/62, 370/60, 370/94.1, 370/110.1, 379/202, 379/203, 379/204, 379/205, 379/206, 379/158
• US Class Current: 370/261
• CPC Class Codes: G06T 1/00 General purpose image data processing
• CPC Class Codes: G06T 2200/16 involving adaptation to the client's capabilities
• CPC Class Codes: H04L 12/1813 for computer conferences, e.g. chat rooms instant messaging H04L51/04; protocols for multimedia communication H04L65/1101; arrangements for multi-party communication H04L65/403; telephonic conference arrangements H04M3/56; television conference systems H04N7/15
• CPC Class Codes: H04L 12/1822 Conducting the conference, e.g. admission, detection, selection or grouping of participants, correlating users to one or more conference sessions, prioritising transmission
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
• CPC Class Codes: H04N 21/4143 embedded in a Personal Computer [PC]
• CPC Class Codes: H04N 21/643 Communication protocols network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP], H04L65/65
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/1324 Conference call
• CPC Class Codes: H04Q 2213/13299 Bus
• CPC Class Codes: H04Q 2213/13337 Picturephone, videotelephony
• CPC Class Codes: H04Q 2213/13389 : LAN, internet

Abstract

The media dependent module provides an interface between an upper-level conferencing driver (e.g., a data-link manager) of the conferencing system and a lower-level communications driver of the conferencing system to isolate the conferencing driver from the communications driver, where the media dependent module is dependent upon hardware of the communications driver. The media dependent module is adapted to perform a plurality of functions called by the conferencing driver. The media dependent module has a connection state machine. In a preferred embodiment, the communications driver is a communications stack that conforms to one of the NetBIOS, IPX, POTS Modem, and TAPI transport standards. The conferencing system may have multiple media dependent modules, each of which provides an interface between the data-link manager and a communications stack that conforms to a different transport standard.

Claims

1. A media dependent module for a computer-based conferencing system, wherein:

the media dependent module provides an interface between an upper-level conferencing driver of the conferencing system and a lower-level communications driver of the conferencing system to isolate the conferencing driver from the communications driver;

the media dependent module is dependent upon hardware of the communications driver; and

the media dependent module is adapted to perform a plurality of functions called by the conferencing driver, wherein the plurality of functions comprises;

a first function for preparing the media dependent module for a conferencing session;

a second function for requesting a connection to a remote conferencing node;

a third function for accepting an incoming connection request;

a fourth function for rejecting the incoming connection request;

a fifth function for initiating a listen mode on an established connection;

a sixth function for closing the established connection;

a seventh function for ending the conferencing session;

an eighth function for retrieving information about the media dependent module;

a ninth function for verifying that a link packet of a specified size can be sent on the established connection; and

a tenth function for sending the link packet on the established connection;

wherein;

the first function is an MDM_-- BeginSession function;

the second function is an MDM_-- MakeConnection function;

the third function is an MDM_-- AcceptConnection function;

the fourth function is an MDM_-- RejectConnection function;

the fifth function is an MDM_-- Listen function;

the sixth function is an MDM_-- CloseConnection function;

the seventh function is an MDM_-- EndSession function;

the eighth function is an MDM_-- GetCharacteristics function;

the ninth function is an MDM_-- ClearToSend function; and

the tenth function is an MDM_-- Send function.

2. The media dependent module of claim 1, wherein the media dependent module comprises a connection state machine.

3. The media dependent module of claim 2, wherein the connection state machine comprises:

(a) an initialization state;

(b) an in-session state;

(c) a connection out state;

(d) a connection in state; and

(e) a connected state.

4. The media dependent module of claim 3, wherein:

calling the first function changes the initialization state-to the in-session state;

calling the second function changes the in-session state to the connection out state;

receiving a connection accepted message from the remote conferencing node changes the connection out state to the connected state;

receiving a connection request message from the remote conferencing node changes the in-session state to the connection in state;

calling the third function changes the connection in state to the connected state;

calling the fourth function changes the connection in state to the in-session state;

calling the sixth function changes the connected state to the in-session state; and

calling the seventh function changes the in-session state to the initialization state.

5. The media dependent module of claim 4, wherein calling any of the fifth, eighth, ninth, and tenth functions leaves the connection state machine unchanged.

6. The media dependent module of claim 1, wherein:

the first function returns synchronously;

in response to the second function, the media dependent module sends one of a connection-established callback and a connection-rejected callback to the conferencing driver and the media dependent module sends a connection-requested callback to the remote conferencing node;

in response to the third function, the media dependent module sends the connection-established callback to the conferencing driver and the media dependent module sends the connection-established callback to the remote conferencing node;

in response to the fourth function, the media dependent module sends the connection-rejected callback to the remote conferencing node;

in response to the fifth function, the media dependent module sends the connection-requested callback to the conferencing driver;

in response to the sixth function, the media dependent module sends a connection-close-complete callback to the conferencing driver and a connection-close-notify callback to the remote conferencing node;

in response to the seventh function, the media dependent module sends a session-closed callback to the conferencing driver; and

in response to the tenth function, the media dependent module sends a send-complete callback to the conferencing driver and the media dependent module sends a data-receive callback to remote conferencing node.

7. A media dependent module for a computer-based conferencing system, wherein:

the media dependent module provides an interface between an upper-level conferencing driver of the conferencing system and a lower-level communications driver of the conferencing system to isolate the conferencing driver from the communications driver;

the media dependent module is dependent upon hardware of the communications driver; and

the media dependent module comprises a connection state machine, wherein the connection state machine comprises;

an initialization state;

(b) an in-session state;

(c) a connection Out state;

(d) a connection in state; and

(e) a connected state, wherein the media dependent module is adapted to perform a plurality of functions called by the conferencing driver, wherein the plurality of functions comprises;

an MDM_-- BeginSession function for preparing the media dependent module for a conferencing session;

an MDM_-- MakeConnection function for requesting a connection to a remote conferencing node;

an MDM _-- AcceptConnection function for accepting an incoming connection request;

an MDM_-- RejectConnection function for rejecting the incoming connection request;

an MDM_-- Listen function for initiating a listen mode on an established connection;

an MDM_-- CloseConnection function for closing the established connection;

an MDM_-- EndSession function for ending the conferencing session

an MDM_-- GetCharacteristics function for retrieving information about the media dependent module;

an MDM_-- ClearToSend function for verifying that a link packet of a specified size can be sent on the established connection; and

an MDM_-- Send function for sending the link packet on the established connection.

8. The media dependent module of claim 7, wherein:

calling the MDM_-- BeginSession function changes the initialization state to the in-session state;

calling the MDM_-- MakeConnection function changes the in-session state to the connection out state;

receiving a connection accepted message from the remote conferencing node changes the connection out state to the connected state;

receiving a connection request message from the remote conferencing node changes the in-session state to the connection in state;

calling the MDM_-- AcceptConnection function changes the connection in state to the connected state;

calling the MDM_-- RejectConnection function changes the connection in state to the in-session state;

calling the MDM_-- CloseConnection function changes the connected state to the in-session state; and

calling the MDM_-- EndSession function changes the in-session state to the initialization state.

9. The media dependent module of claim 8, wherein calling any of the MDM_-- Listen, MDM_-- GetCharacteristics, MDM_-- ClearToSend, and MDM_-- Send functions leaves the connection state machine unchanged.

10. The media dependent module of claim 7, wherein:

the MDM_-- BeginSession function returns synchronously;

in response to the MDM_-- MakeConnection function, the media dependent module sends one of a connection-established callback and a connection-rejected callback to the conferencing driver and the media dependent module sends a connection-requested callback to the remote conferencing node;

in response to the MDM_-- AcceptConnection function, the media dependent module sends the connection-established callback to the conferencing driver and the media dependent module sends the connection-established callback to the remote conferencing node;

in response to the MDM_-- RejectConnection function, the media dependent module sends the connection-rejected callback to the remote conferencing node;

in response to the MDM_-- Listen function, the media dependent module sends the connection-requested callback to the conferencing driver;

in response to the MDM_-- CloseConnection function, the media dependent module sends a connection-close-complete callback to the conferencing driver and a connection-close-notify callback to the remote conferencing node;

in response to the MDM_-- EndSession function, the media dependent module sends a session-closed callback to the conferencing driver; and

in response to the MDM_-- Send function, the media dependent module sends a send-complete callback to the conferencing driver and the media dependent module sends a data-receive callback to remote conferencing node.