PATENT ABSTRACT
The present invention manages media gateway control (megaco) protocols according to changes of lower layer network protocol by implementing the megaco package in the network adaptor. A method for managing the megaco protocols by using a network adaptor includes steps of: a) requesting an installation of a megaco protocol package to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package; and e) installing the megaco protocol packages and the specific megaco protocols, and managing the megaco protocols.

PATENT DESCRIPTION
FIELD OF THE INVENTION 
   The present invention relates to a media gateway control (megaco) protocol management method using a network adaptor, and more particularly, to a megaco protocol management method for independently managing the megaco protocols according to changes of low level network protocols by implementing the megaco package in the network adaptor and a computer readable recording medium for executing the same method. 
   DESCRIPTION OF THE PRIOR ART 
   A Voice over Internet Protocol (VoIP) is an application technology of the Internet for transferring voice data that is compressed and packetized by end-to-end channel setting base upon Internet Protocol (IP) address. A gateway is necessary so as to provide VoIP through the Internet and terminates Public Switched Telephone Network (PSTN). The gateway is an apparatus for interconnecting signals and media between two networks. 
   The VoIP is connected to a Signaling Gateway (SG) by a media gateway controller for controlling a call process. The media gateway controller controls the media gateway by translating a call number, allocates available Internet Protocol (IP) address by controlling the media gateway and interconnects voice traffics of each terminal by managing compression methods to generate end-to-end IP packet. 
   By separating the media gateway and the signal gateway, independence of an applied protocol is guaranteed, protocol is scalable and service can be easily changed although a new service is added. 
   A gateway is functionally divided into a signal gateway, a media gateway and a media gateway controller. The media gateway transforms data that are used in circuit switching network into data that are used in packet switching network. The media gateway includes a Residential Gateway (RGW), an Access Gateway (AGW) and a Trunk Gateway (TGW). 
   A media gateway control (megaco) protocol is used for communication between the media gateway and the media gateway controller in VoIP service. The megaco protocol defines a communication method between the media gateway and the media gateway controller and is a protocol in master-slave format that the media gateway controller sends instructions for connecting and managing media gateways. Traffic processing of the media gateway is similar to that of node in typical switch. 
   Also, a megaco protocol engine supports communication between the media gateway and the media gateway controller by using the megaco protocol. The megaco protocol engine is interconnected to many low level network protocols, e.g., a Transmission Control Protocol (TCP), a User Datagram Protocol (UDP), Stream Control Transmission Protocol (SCTP), an Asynchronous Transfer Mode (ATM) and Time Division Multiplexer (TDM). 
   New version of the protocol has been developed day by day. As a result, the number of the protocols for being considered by the megaco protocol engine in order to be matched is incredibly increased. Therefore, a source of the megaco protocol engine must be revised whenever the megaco protocol engine is installed according to changes of network protocols or protocol versions. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a megaco protocol management method for independently managing the megaco protocols according to changes of low level network protocols by implementing the megaco package in the network adaptor and a computer readable recording medium for executing the same method. 
   In accordance with an aspect of the present invention, there is provided a method for managing media gateway control (megaco) protocols by using a network adaptor, including steps of: a) requesting an installation of a megaco protocol package of low level network protocols to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table in case that the megaco protocol does not exist in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package in case that the megaco protocol exists in the network protocol table; and e) installing the megaco protocol packages and the specific megaco protocols and managing the megaco protocols. 
   In accordance with another aspect of the present invention, there is provided a computer readable recording medium including a microprocessor in communication systems using a megaco protocol, including the instructions of: a) requesting an installation of a megaco protocol package of low level network protocols to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table in case that the megaco protocol does not exist in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package in case that the megaco protocol exists in the network protocol table; and e) installing the megaco protocol packages and the specific megaco protocols and managing the megaco protocols. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which: 
       FIG. 1  is an exemplary block diagram showing a Voice over Internet Protocol (VoIP) service system in accordance with the present invention; 
       FIG. 2  is an exemplary block diagram illustrating a media gateway in accordance with the present invention; 
       FIG. 3  is an exemplary block diagram depicting a media gateway control (megaco) protocol engine in accordance with the present invention; 
       FIG. 4  shows a network protocol table and a megaco package list in accordance with an embodiment of the present invention; 
       FIG. 5  is a flowchart for explaining management procedures of the megaco protocol by using a network adaptor in accordance with the embodiment of the present invention; and 
       FIG. 6  is a flowchart for explaining procedures for adding a new protocol in the network protocol table by using a network adaptor in accordance with the embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is an exemplary block diagram showing a Voice over Internet Protocol (VoIP) service system in accordance with the present invention. 
   A media gateway control (megaco) protocol is the protocol used in the Internet. It is distinguished from a protocol used in a Public Switched Telephone Network (PSTN). A call processing unit and a media processing unit were built on one device for the PSTN and the mobile network. However, the call processing unit and the media processing unit are separately implemented as an independent device for the Internet network by standardization of the megaco protocol. Such a separation of call processing unit and media processing unit makes it possible to expand media transfer device for expanding the network. 
   Referring to  FIG. 1 , the terminals include an Internet outgoing terminal  21 , a wireless terminal  20  connected to an access point  19  over the air, a terminal  16  connected to a Residential Gateway (RGW)  6 , a terminal  17  connected to an Access Gate (AGW)  7  and a terminal  18  connected to a Private Branch Exchange (PBX)  8 . The terminal connected to the Internet requests an Internet voice telephone service. 
   The request is transferred to a call server  1  through a media gateway controller  2 . Internet telephone call is connected to the PSTN  10  or the mobile network  11  through a Signal Gateway (SG), a Signaling Transfer Point (STP) and a Service Control Point (SCP). 
   Once the Internet telephone call is connected, the Media Gateway Controller (MGC)  2  controls a Trunk Gateway (TGW)  9  by using the megaco protocol to deliver the call to the terminal of the PSTN or the mobile network through a switch  12 , a Mobile Switching Center (MSC)  13  or a Packet Data Serving Node (PDSN)  14 . 
     FIG. 2  is an exemplary block diagram illustrating a media gateway in accordance with the present invention. 
   Referring to  FIG. 2 , a media gateway  9  includes a call processing unit  201  for processing calls from a transmitting channel and a receiving channel, a protocol processing unit  202  for processing protocols, e.g., a megaco protocol, a system controller  206  for controlling a media gateway system, a codec  203  for transforming an analog voice signal to a digital voice signal, a trans-codec for transforming a different format of codec to an adequate format of codec, a dynamic media controller  205  for allocating and controlling voice codec data in Real-time Transport Protocol (RTP) payload and a hardware platform for providing a hardware for operating the media gateway  9 . 
   A media gateway control protocol engine is included in a protocol processing unit  202  of media gateway. The media gateways  6 ,  7  and  9  communicate with a media gateway controller  2  by using a media gateway control (megaco) protocol. 
     FIG. 3  is an exemplary block diagram showing a megaco protocol engine in accordance with the present invention. 
   Referring to  FIG. 3 , a megaco protocol engine  300  includes a connection management unit  303  for managing a connection between a transmitter and a receiver, an instruction processing unit  304  for processing instructions, a package processing unit  305  for processing a megaco protocol package, a transaction management unit  306  for managing a transaction for call processing, a encoder/decoder for encoding and decoding the megaco protocol, a network adaptor  308  for interconnecting network protocols, an administration interface  302  for providing an interface in order to manage the megaco protocol, an Operating System (OS)  309  and a system adaptor  301  for connecting a Digital Signal Processor (DSP)  310 . 
   Particularly, the network adaptor  308  interconnects various low level network protocols including a Transmission Control Protocol (TCP), a User Datagram Protocol (UDP), Stream Control Transmission Protocol (SCTP), an Asynchronous Transfer Mode (ATM) and Time Division Multiplexer (TDM). 
     FIG. 4  shows a network protocol table and a megaco package list in accordance with an embodiment of the present invention. 
   The network adaptor  308  needs a network protocol table  410  and a megaco package list  420  to install the megaco protocol package to the low level network protocols. 
   The protocol information table (Network_Protocol_table)  410  is used for managing the megaco protocol according to characteristics of low level network protocol such as TCP, UDP or SCTP. 
   Referring to  FIG. 4 , the network protocol table  410  includes protocol identification (ID)  411 , protocol version information  412 , company information  413  and specific package ID  414 . 
   The protocol ID  411  is an identification defined for discriminating a target network protocol to be interconnected by the megaco protocol engine. Examples of the protocol IDs are defined as 0001 for UDP, 0002 for TCP, 0003 for SCTP, 0004 for RTP, 0005 for ATM and 0006 for TDM in a preferred embodiment of this present invention. 
   Protocol version information  412  represents a version of the protocol defined by the protocol ID  411 . Examples of the protocol version information  412  are defined as 01 for version  1 , 02 for version  2  and 03 for version  3  in a preferred embodiment of this present invention. 
   Company information  413  is used for requesting specific megaco protocol in case that protocol standard is not defined or a protocol is developed regardless with the protocol standard. Examples of the company information  413  are defined as 0001 for company  1 , 0002 for company  2 , 0003 for company  3  and 0004 for company  4  in a preferred embodiment of this present invention. 
   The specific package ID  414  is an identification of a megaco protocol package in a megaco package list  420 . The specific package ID  414  corresponds to package identification (ID)  421  of the megaco package list  420 . That is, the specific package ID  414  is used as an identification of the megaco protocol package that is installed in the megaco package list  420 . 
   Regardless of adding or updating of a new low level network protocol, the megaco protocol package is independently installed in the megaco protocol engine by using the network protocol table  410  that has the protocol ID  411 , the protocol version information  412  and the company information  413 . 
   The megaco package list  420  includes package ID  421 , package version information  422 , property information  423 , event information  424 , signal parameter  425 , statistic information  426  and specific protocol ID  427  for defining other characteristics of megaco protocol package. 
   The package ID  421  is an identification of the megaco protocol package. The package version information  422  defines changes of the property information  423 , the event information  424 , the signal parameter  425 , the statistic information  426  and the special protocol ID  427 . 
   The property information  423  defines data type. Examples of the property information  423  are string, UTF-8 string, integer, 4 byte signed integer, double, 4 byte signed integer, character, enumeration, sub-list and Boolean. 
   The event information  424  is used for the media gateway controller  2 . The signal parameter  425  is an identification of information between the media gateway controller  2  and the media gateway. 
   The statistic information  426  represents a unit, e.g., a second or a packet. 
   The specific protocol ID  427  is an identification of a specific protocol. 
   Management procedures of the megaco protocol in accordance with the present invention are explained by using the network protocol table and the megaco package list. 
     FIG. 5  is a flowchart showing management procedures of the megaco protocol by using a network adaptor in accordance with the embodiment of the present invention. 
   At step  501 , the media gateway  9  receives a list of requests for installing package from the media gateway controller  2  and requests an installation of the megaco protocol package to the network adaptor  308 . 
   At step  502 , the network adaptor  308  receives the request for installing the megaco protocol package and searches a protocol of the list in the network protocol table  410  that has fields of the protocol ID  411 , the protocol version information  412  and the company information  413 . At step  503 , it is determined whether the protocol exists in the network protocol table  410 . 
   If the protocol does not exist in the network protocol table  410  at step  503 , at step  504 , a new protocol is added in the network protocol table  410  and the management procedure is finished. 
   If the protocol exists in the network protocol table  410  at step  503 , at step  505 , the specific package ID  414  is extracted from the network protocol table  410  and the network adaptor  308  searches the megaco protocol package in the megaco protocol package list  420  by using the specific package ID  414 . At step  506 , it is determined whether the searched megaco protocol package is the specific megaco protocol package by using the specific protocol ID  427  of the megaco protocol package list  420 . 
   If the searched megaco protocol package is not the specific megaco protocol package at step  506 , the process proceeds to step  508 . 
   If the searched megaco protocol package is the specific megaco protocol package at step  506 , at step  507 , the specific megaco protocol package is connected. 
   At step  508 , it is determined whether every protocol of the list is processed completely. If every protocol in the list is not processed yet, a procedure continues to step  502 . 
   At step  509 , megaco protocol packages and specific megaco protocol packages are installed. 
     FIG. 6  is a flowchart showing procedures for adding a new protocol in the network protocol table by using a network adaptor in accordance with the embodiment of the present invention. 
   At step  601 , a request for adding a new protocol in the network protocol table  410  is received. At step  602 , it is determined whether the new protocol exists in the network protocol table  410 . 
   If the new protocol exists in the network protocol table  410 , the process is finished. 
   If the new protocol does not exist in the network protocol table  410 , at step  603 , fields of the protocol ID  411 , the protocol version information  412  and the company information  413  is stored in the network protocol table  410 . 
   At step  604 , it is determined whether the new protocol needs a new megaco protocol package. 
   If the protocol does not need a new megaco protocol package, at step  605 , the specific package ID is stored in the existing field of the specific package ID  414 . If the protocol needs a new megaco protocol package, at step  606 , a new megaco protocol package is generated, a new package ID  421  of the new megaco protocol package is allowed and the new package ID  421  is stored. 
   At step  607 , the new megaco protocol package is added in the megaco package list  420  and each field of the megaco package list  420  is stored. 
   At step  608 , the new package ID  421  is stored in the new specific package ID  414  of the network protocol table  410 . 
   As mentioned above, although the number of network protocols and protocol versions has been increased, the megaco protocol can be operated by independently managing the megaco protocol according to changes of lower layer network protocol by implementing the megaco package in the network adaptor without revising the source of the megaco protocol engine. 
   The method of the present invention can be implemented as a program and stored in a computer readable medium, e.g., a CD-ROM, a RAM, a ROM, a Floppy Disk, a Hard Disk, and an Optical magnetic Disk. 
   While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.