Establishing communication in a packet data network

Description: TECHNICAL FIELD [Detailed description of the invention]

How to set up communication on a packet data network The present invention relates to a method of setting up communication between a source user and a destination user.

[Introduction] Traditionally, communication between remote terminals is a dedicated lease line or public exchange network, originally It is based on the use of an analog speech-based public switched telephone network. Tiger Subsequent digitization of the link network will include the installation of exchange digital communication channels. , Facilitating the adoption of international standards such as Integrated Services Digital Network (ISDN) .. Recently, the use of data services has dramatically increased due to the expansion and availability of the Internet. Increasing, thereby bringing data communications to Internet service providers It is carried out over a long distance by the local calling means of. Data service demand With access to the Internet, in addition to the increase in the number of users, modems Personal computers with data communication equipment such as and similar computers Installed an engine, thereby further across the voice-based transmit channel Enables new advances in increased data rate transmission. The need for data transmission in addition to general voice and facsimile transmission is new It is also recognized and transferred when digital transmission standards are established for mobile communications such as GSM. Dynamic communication is the communication of data that normally contains a large level of interleaving. Provides an enhanced transmission protocol for wireless communication, thereby providing a common burst in wireless communication Reduce data loss caused by errors. Personal computers and workstations are common in business environments Became a target, began to be adopted daily, desks beside phone handset everywhere It is placed as top equipment. In addition, the operation of the personal computer and the telephone Many exclusive programs on a daily basis to strengthen and improve work relationships Is used by executives and office workers to replace calendars, diaries, address books, etc. Used to record information about the information. In addition, personal computers and telephones A modem located between the lines keeps a record of the communication as it takes place. , Modem is point-to-point or phone call by email provider Contact It can be used for data transmission, and also directly provides a fax machine. It is possible to provide. Many of these different types of communications work very well, each individually. Seems to give excellent problem-solving when viewed in. However, this There is also much to be desired in the interaction between these different services. Shi Therefore, set up a phone call, send a fax, send data, inter Access large networks such as the net and pay-per-use networks It is possible to provide software to do this, but it is different to establish a specific connection Care must be taken to switch between the broken connections. Therefore After using the modem for certain functions, such as setting up a phone call, the modem is usually Data services or other services such as facsimiles before they are sent to Requires some restructuring to access. So, for example, par The sonal computer may consist of a facsimile drive, which is another device. Receive a fax by its associated modem before accessing the database And allows transmission, but removing this drive from memory Personal computer required, thereby communicating with the database It is not possible for a fax machine to receive a fax. Therefore, in the technique of the present invention Therefore, personal computers are secondary when high communication capacity is present. The start call is usually made by telephone. Numerous devices like audio phones, mobile phones, video and data transmissions It is very difficult to identify the exact location of a destination when ip communication takes place. Become. Existing exchange technology sets physical links between users, which is the destination It is only efficient if the user stays in a certain position. Similarly, each destination ad When exchanging packets of data with attachments, the source user aims You need to know the destination of the recipient. This will increase usage by email Includes storing and transferring systems such as, for direct real-time communication technology There is little reliability. The current problems with this type of development are these origins. Exhibitions tend to reduce the use of real-time connections, and real-time connections are for certain customers. This reduces the overall efficiency of the communication structure.

[Summary of invention] Communication is established between the source user and the destination user according to the first feature of the present invention. A method is given to determine the data, which is the destination address and communication data. Is transmitted between users in a packet with, identifies the destination name, and sees the packet as the eye. The packet is sent to the service control platform that identifies the place name, and the packet is controlled. Identifying the contactable address of the destination from the platform Said to return to the source and send to said destination with said returned address It has a step of generating a data packet at the source. In a preferred embodiment, the data follows an internet acquisition protocol. Will be sent. Preferably, the destination name is identified from the name display list. Of the name The display list is obtained from a local database, but in a preferred embodiment the name The previous display list is from a database maintained by the service control platform can get. Preferably when the communication session is started, the data of the name is the user It is sent to ensure that the list is updated regularly. The name data may be sent as an HTML page. Operate to set communication to the destination user according to the second feature of the present invention. A source user device arranged to receive instructions from the data is provided, and this device The location is a means of identifying the destination name to the service platform and responds to the identification. As a means of receiving a contactable address from the service platform, Data package to the destination user identified by the received contactable address It is equipped with a means for supplying a device. In a preferred embodiment, the device goes through a local network and a plurality of similar sir. Connected to the service, the network is connected to the service platform Contains the node that is. Preferably the ISDN connection is between the node and the plug. It is provided between the tofoams. Further, between the user device and the service node. Transmission may be in accordance with Internet Protocol. A service platform is provided according to the third feature of the present invention. This service platform is available from user terminals and source users. Includes user addresses that have the means to receive inquiries about the destination address To obtain the means of communicating with the database and the destination address of the destination user The means for accessing the database and the details of the destination address are described in the saw. Equipped with means to return to the user, thereby using the destination address By generating a data packet, the source user becomes the destination user. Provide communication with. In a preferred embodiment, the gateway to the World Wide Web is user-generated. You will receive commands that allow you to remotely control the functional features of the rat form. It is aligned like a sea urchin.

[A brief description of the drawing] Figure 1 shows a typical circuit switching network for voice telephones. Figure 2 shows a typical packet switching network such as the internationally recognized Internet. Is shown. Figure 3 shows the service platform sending multiple transmissions, including the local network. A network in which the present invention is implemented for mutual communication in an environment is shown. Figure 4 details the type of local network shown in Figure 3. Figure 5 shows the details of the service platform shown in Figure 3. Figure 6 shows the user display on which the data page is displayed. FIG. 7 shows the operation of the network shown in FIG.

[Explanation of preferred embodiments] The present invention will be described by way of example only with reference to the accompanying drawings described above. A typical circuit replacement environment is shown in Figure 1, where the handset 101 etc. The telephone handset is connected to an exchange node such as exchange node 102. Start call Therefore, the signal transmission information is generated by the telephone handset 101, and this information is exchanged. It is relayed to the replacement node 102. Intelligent control for exchanging signals Distributed or a high percentage of control is centralized and signaled over the network Communication information is transmitted over a common signal transmission transmission path. Therefore exchange node 10 2 and several other exchange nodes 103, 104, 105 under service control point (SCP) 106 It may be controlled by. With such a controlled network, an intelligent network It can include additional services known as Therefore, usually For customers using the telephone handset 107, the control processor 106 has Meaning that this user has been at Phone Handset 108 over time It is possible to convey information. Under these circumstances, the first customer is switching Provides signal transmission from the telephone handset 101 interpreted by node 102. This Information is relayed to SCP106, which instead recognizes this signaling information. Programmed to direct the call to the telephone handset 107 It is guided to the telephone handset 108 with priority over being done. The problem with such configurations is that the network reorients this type of call. Must include a large amount of processing capacity to do this. Network provider Be in one position to justify the cost of setting up such a network But such network providers are facing competition from alternative structures It must be recognized that making such an investment in the future Not so attractive. An alternative structure is shown in Figure 2, where source user 201 is destination user 2 Has data to be sent to 02. Information is sent as a data packet, net The central part of the work is considered to be the packet switch 203. The entire typical packet is indicated by 204, which communicates with address section 205. It consists of a data part 206. User terminal 202 can be limited by source terminal such as terminal 201 It may be identified by a capable address. Terminal 201 has communication data of terminal 202 When the data is grouped into multiple packets, the packets are packets. The appropriate address is added to each packet before it is fed to the switch 203. Usually double Each packet is resolved within a packet switch consisting of a number of programmable processors. It is analyzed and as a result of this analysis the passage is identified through the network, thereby As a result, the packet is received by the user terminal 202. Packet switch 203 No permanent circuit is configured through it, and each packet must be individually considered and routed. Must be. Packet loss is actually possible and information in such an environment Is lost and therefore information is sent to the sending terminal when the lost packet is retransmitted. Protocols are usually given to ensure that they are relayed back. available. Similar protocols also serve as a mechanism for giving levels such as error correction. Exists. The Internet represents a robust example of the environment shown in Figure 2. I Internet is a transfer control protocol / Internet protocol (TCP / IP) ) And its unique transmission protocol, including Hypertext Transfer Protocol (HTTP) It is set in Kol, and the use of the latter (hypertext transfer protocol) is "wa" A unique subsection of the Internet under the name "World Wide Web (WWW)" Recognized by The Internet uses a decentralized processing engine, which is for individual user terminals Effectively network as if they were user terminals connected to the network Become a part of Therefore, in order to perform data communication via the Internet, A program called a "browser" needs to be run on the user terminal, which Overall network integrity by the processing equipment given by the user himself Is highly dependent. Many problems occur on the Internet, but most of these are for most users Due to the limited bandwidth available to. To make a high bandwidth connection Therefore, many problems are overcome, and real-time voice communication and real-time video communication are connected to the Internet. Experiments have shown that this is possible using the T protocol. the Internet It has a number of limitations in itself and is very important when it comes to directing messages to destinations. A type of "intelligent ne" that is durable but can be used in a circuit switching environment. It is not possible to provide any "work" service. , A directive to the effect that a user residing in terminal 202 generally resides in terminal 206 on a particular day Is not possible to give to the Internet. Ordinary allen on the internet Diment buffers messages in the form of emails, periodically sending emails To access. The user identifies the username from different terminals and emails Allows access, but source you that the destination user has moved If the is not informed, the source user will know where the destination user actually resides. It is impossible to know, and therefore the source user can take the information to an alternative location. Is not possible. The network in which the present invention is implemented is shown in FIG. Internet Most of the network uses Rotocol and its own servers and browsers , Looks similar to the configured internet. However, you The level of bandwidth given to The is enhanced and communication is an intelligent service. Managed by ratform and called by associated intelligent protocol Networks are very different in that they are designed to give a certain level of redirection. It has become. Thailand shown in Figure 2 according to the configured internet protocol Information is transmitted in the packet switching environment. In the environment, the source user is the destination It is possible to identify the address of the user, thereby over the network And send the packet. However, in addition to this basic level of service The call is redirected in response to the information received from the service platform It is also possible. However, service platforms are common circuit crossovers. The type that does not include a converter and is therefore used in the circuit exchange environment shown in Figure 1. This redirection cannot be done using the technology of. In addition, the inter When there is competition from networks such as the Internet, a large amount of processing power is serviced. It is not possible to occur within the rat form, the distribution available on the user terminal Must depend on the processing power. Therefore, the present invention has a net processing capacity. Intelligent node type in the environment distributed between the work element and the user terminal Address issues regarding how to make a transmission. As mentioned above, the source user generates a packet with a destination address. It is possible to make the internet protocol technology set by it Therefore, the packet is distributed over the network and addressed to the destination. Received by. This mechanism is from the source user to the network element and address. Developed in the present invention to set up a connection to a customer. When performing the processing of the present invention, the source user can effectively use the service platform. Identify the destination name to the room. The service platform is the destination Yu at this stage Not involved in setting up a connection to the user. As mentioned earlier, this type of connection Settings are overlaid with the configured Internet Protocol Intelliger Must be initiated by the source user according to the protocol. The service platform therefore parses this information and references the database. In response to this analysis, the service platform of the previously identified destination Returns the information that identifies the contactable address to the source user. Therefore, first Need to know the actual address of the destination user that the source user wants to contact There is no. However, identifying the destination user to the service platform , The address information is returned to the source user, thereby making the source user true. Allowed to aggregate new packets with identified destination user addresses , Send communication data packets to the network at the appropriate address attached It is possible to be done. Therefore, the network behavior shown in Figure 3 is shown in Figures 1 and 2. It is very different from the environment. In the environment shown in Figure 1, the data for setting up the call Transmission is effectively a one-way process. In a packet switching environment such as the Internet The packet is generated by the address and directed to the user. In a circuit exchange environment, Calling information is supplied to the network, resulting in physical channels as the source. And set between destinations. In an embodiment of the invention, the destination address is first known. Not done. The source user is a service platform by automatically generating messages. Inquire effectively. The service platform is in that database Queries and generates the returned message of the source user. The source user is that Later, a new par with the destination address identified by the service platform Automatically reassemble the kets. The source user knows the destination address, but identifies the characteristics of the communication being made. There is an additional level of complexity that no information is given. Source user it It is possible to effectively send a message to the late identified destination and set up communication. If it is possible, ask the destination. If the identified destination is operational, then the emotion The information returns to the source, this information first states that communication is possible, and secondly communication. Identifies the protocol to configure. So, for example, these protocols State that the destination can perform video transmission. Instead, the destination is Returns information to the effect that only audio communication is possible. When this information is passed to the source user, the source user is directed to the identified destination. On the other hand, we are in a position to generate packets of meaningful communication data. Therefore, this Transmission of these packets is started, and the communication channel is the source user and the destination you. Generated between the. Information is received by the destination user and this information includes address information The destination user alternately returns the information to the source user. In this way, start Provide complete bidirectional two-way communication between the source user and the destination user to receive. And is possible. In addition to allowing communication to be configured this way, the service plug The form 301 can also perform additional functions. Customers of a particular service There are relatively high bandwidth digital communication links, eg each user location 305 , 306, 307 are provided with ISDN channels 302, 303, 304, etc. Each you The location takes the form of a local area network, with multiple individual users Allows you to gain access to The Port. In this way, position 305 User requests a connection to a user who normally resides at location 306. But However, the user at position 306 will be serviced to the effect that he / she will live at position 307 on a specific day. I'm instructing Toform. In these situations, the username does not change, but The address of the user is changed in the database, and as a result the message is directly new. You will be guided to the target position. Under some circumstances, it is not available to the user and therefore the service platform Data messages and voice messages stored within the platform for later retrieval Make selections such as sage, fax messages, and email. Further message The service may be searched using the configured service connection (302, 303, 304, etc.) I. Instead, it was set as described in UK Pat. No. 9527326. Different access means such as the World Wide Web may be provided. Especially this Connections such as setting up a call redistribution method and searching for stored messages Do. In the embodiment shown in FIG. 3, yet another function is a unique and different proto. Given by accessing a configured communication system that operates on the col .. In this way, the service platform is the Public Switched Telephone Network (PSTN) 30 8, general ISDN network 309, cellular network such as GSM310, Gain access to other packet-switched networks such as the Field Wide Web 311 Make it possible to obtain. In addition, PSTN, ISDN, GSM, or WWW Access service users at any available location 305, 306 or 307 Access is also done in the opposite direction. A typical user position, such as user position 305, is shown in FIG. Multiple ends The ends 401, 402, 403 are private communication networks such as Ethernet or ATM networks 4 It is connected to 04. The network is also connected to network server 405 This alternates over ISDN2 interface 406 and connection 302 Access service platform 301. Private communication network 404 can send packets according to the Internet protocol It is configured to enable, which allows terminal 401 to local network 4 Generate a TCP / IP address for another terminal connected to 05. Similarly, ad Les are identified by other user positions 306, 307 and addresses are generated in other environments 308-311 May be done. System so that the actual destination location is virtually transparent to the operator The service is configured and the simple user behavior is a service whirl as shown in Figure 3. Allows connections to be made anywhere in the box. At this stage, the manual operation performed by an actual human being, hereinafter referred to as the "operator", , The distinction from the automatic processing operation performed by the operator terminal, which is hereafter referred to as the "terminal", is recognized. It is important to know. Similarly, multiple terminals are connected together via the premises communication network, and Thus, in combination with the server, these are specific units such as location 305, 306 or 307. User perceived by service platform 301 as a user residing in the location It is expressed as a user. The service platform 301 is shown in Figure 5, which is the interconnect circuit 501. , Service control node 502, database 503, message storage device 504 , PSTN gateway 505, ISDN gateway 506, and GSM gateway It consists of 507 and WWW gateway 508. Circuits 501 to 508 are service control nodes A operated under the control of 502 and implemented as a Unix processing environment Communicate with TM premises communication network 509. The interconnect circuit 501 is a physical intermediary for ISDN transmission through communication paths 302, 303, 304. Give a face. The interconnect circuit receives ISDN transmissions and modifies such transmissions. And thereby suitable for supplying these transmissions to the service control processor 502 Make it a painful form. Similarly, the interconnect circuit 501 is sent from the service control processor 502. Modify these to receive messages and send them over ISDN connections 502-504 To. The interconnect circuit 501 interconnects the service user and thus the user Allows communication with the configured TCP / IP protocol. Therefore, you The processing equipment available at the location is the utilization given by the service platform It is used without imposing a processing burden on possible processing resources. In this way , The processing utilization level of the service platform has been substantially reduced, and the communication environment Increase competitiveness. Three different nodes may be identified to allow configuration of the connection. No. First, the device probably references a locally stored directory to add another device. Generate a reply, thereby sending a local network like a network 404 It was simply included in the package, or instead received, for example, on an ISDN connection 302. Later, the communication is used within the user position 307 by the interconnection circuit 501, so it is a substitute for 304 etc. Redirected to the alternative ISDN channel. Under these circumstances, the service No rat form is used, and the transmission address is exclusively controlled by the user device. Be controlled. Under the second mode of operation, the operator identifies the destination name and as a result the operator Each terminal of the service control the data packet via the interconnection circuit 501 Generate the address to be supplied to the 502. Service control node 502 requires The user is identified and database 503 is accessed. Received from database 503 In response to the information provided, the actual user whose service control node 502 is being called It is possible to identify the destination address and the called user is in location 307 A resident user. This information is returned to the communication path 302, where the operation of the terminal 401 etc. is performed. Processed by the lator terminal. Human operators are effectively aware of this communication No, the terminal 401 is an address supplied to it from the service control node 502. Automatically generate a new information packet containing the packet. In this way, terminal 401 is true It is possible to generate a new packet with the destination address attached .. Therefore, after receiving this information, the second type of communication is said to be the first type. It can be practically done according to the communication of. Especially information packets Supplied to interconnect circuit 501 without resources to service control processor 502 It will soon be redirected to user position 307. Under the third mode of operation, the operator again identifies a particular destination name, resulting in Each terminal generates an information packet intended for service control node 502. .. Under the control of service control processor 502, information is retrieved from database 503. , Which causes the service control processor 502 to be retransmitted back to terminal 401. Allows information packets to be aggregated and effectively identifies the true address of the destination To do. However, in this case, the destination is not the actual customer of the service, ie Instead, the customer services to the effect that the call should be redirected to another sending environment. Direct the platform. Under these circumstances, address data is an additional data. Identifies the address of a particular gateway 505-508 to which dress information is attached, The attached address information is acted upon by the gateway, which makes the call Allows you to connect via PSTN, ISDN, GSM or WWW etc. To. Therefore, in these situations, terminal 401 issues information packets in the usual way. Birth and this is redirected to the appropriate gateway through interconnect circuit 501 .. This imposes additional communication on the ATM network 509, but with a service control processor. Does not depend on sasa 502. At the selected gateway, the address information is identified and This allows the call to be set up in the proper environment and the protocol Conversion occurs and therefore is generated, for example by the user position, and sent in the form of packets The trusted speech data is aggregated in a continuous stream so that it is transmitted via the PSTN. Converted to PCM style or analog speech. Similarly, ISDN309, GSM3 This type of conversion is done to be sent via 10 or WWW311 etc. W311 requires virtually less conversion if similar protocols are used .. Service platform 301 is not part of the configured "Internet" However, using the protocol set for the Internet, terminal 401 is TCP / Run an IP-based HTML browser. With service control processor 502 Communication between individual terminals such as terminal 401 is HTT for service presentation Made using P, the service control processor 502 is an HTTP daemon (HTT) Associated with PD). When connected to the service platform, the operator goes through the service terminal It is in a position to perform all communication. As a result, the service platform Internal private dating if it is possible to achieve a connection to PSTN308 via 301 Operate the converter and finally the separate phones connected to the configured PSTN No need to give to data. In addition, individual operators enable a special type of communication No special preparation is required to do so. Especially for operators A lectry is given and the operator can operate remotely with other local operators. And finally through the appropriate gateway to service platform 301 Quickly set up communication with anyone connected to any type of network you access Allows you to. Therefore, it is suitable for the operator terminal to communicate. The idea is to start the operation in mode. Operator email message Check your page or other memorized messages regularly before starting any other work If so, this is especially attractive. These other jobs are probably backgrow Communication applications that exist as a process, especially Unix or Wi Many irrelevant applications due to multitasking environments such as Windows 95 Made using. Therefore, in other tasks that use other applications Is active, but the local browser is operational and thereby comes in Warns the operator of the call and allows the operator to take appropriate action To. Therefore, the terminal tells the operator local communication, regional communication and finally the world. It provides the only way to access both world-wide communications. The operator usually urges the terminal, which is remembered to connect to the communication service. Automatically execute the program or script that has been created. In this way, with a terminal The message is sent to the service processor 502 and to the processor. Notify that the operating terminal is active. HTTPD associated with service control processor 502 is HTML customized Return the page to the operator terminal, and the visible display of the device 601 etc. shown in Fig. 6 Screen so that the graphic image is displayed to the operator on the spray device Execute Puto. Pages generated by HTTPD are obtained from database 503 Information that identifies the existence of individual stored calls 603, including special user information Contains the window 602 shown. These are calls directed to the operator , The operator's terminal is not active. These calls are voice calls, emails , Or other types of transmittable data, such as fax transmissions. I. The window is a scroll bar 60, as is well known in the window environment. Contains 4. Similar windows 605 with similar scrollbars 606 are featured by the operator Identifies a directory with a fixed name and quickly connects to regularly called destinations Do. This type of private directory is colloquially known as a "buddy list" And often called destinations, that is, people with whom the operator usually has an intimate relationship Identify the destination involved. Therefore each entry 607 is a table in the directory All of these entries are shown by manual action performed by the operator. May be expanded. The page displayed by the display device 601 also contains a soft button. This button consists of a search button 608, a contact button 609, and an expand button 610. These buttons were displayed by the control device, often by the manual operation of the mouse. It is accessed by adjusting the position of arrow 611 of the cursor. Mouse and its associated mosquitoes -Sol's device searches for memorized calls and contacts directory entries. Is made possible. This type of action is a call en that stores the cursor 611. It consists of moving to a position that identifies one of the birds 603. Left mouse button Is then urged and the entry selection is identified by changing the color. further The manual movement of the mouse points the cursor 611 to the search button 608. Mosquitoes -While the sol is located on the search button 608, press the appropriate mouse button to select The call made is retrieved from storage. This is the audio given to the right device It is a form of signal. Facsimile information is displayed instead or other types of notes Data is made accessible. The memory of this type of facsimile information is real Quality is similar to that described in the previously filed specification. A similar mechanism directs by moving cursor 601 to the appropriate entry 605 Used to select tri-entries and urge contact button 609. this When urged as such, the packets are aggregated by the terminal and the service control processor 50 Sent to 2. The third soft button 610 allows other characteristics to be accessed by the deploy function Make it possible. In this way, you can add entries to the directory, business, residence Machine to access the central directory such as the phone book or classified directories of Changes in capabilities and selections may be accessed. The expand button also ends a particular function However, as mentioned above, the process is active as a background process. The system is designed to be buoyant, which allows the operator to do other work. Communication can be set while engaging in. The process of making calls between users using the service control processor 502 is detailed in Figure 7. It is shown in. In step 701, the destination is identified by the name from the directory And here the "contact button" 609 is urged in step 702. This process is Manually performed by the operator as described above, probably in the form of voice communication No further operation is required on the operator side, except for the generation of source information. I. At step 703, the operator's terminal sends a message to the platform 301 sir. Sends to the screw control processor 502, and the service control processor 502 steps instead. Return the destination address to the terminal at 704. Using the address returned by service control processor 502 in step 705 , The terminal generates a new message to the destination requesting communication settings. Messages are sent directly through circuit 501 interconnects or at the appropriate gateway. Is sent to the destination, and the resulting message is analyzed in step 706 at the destination edge. It is done by the end. At step 707, a question is asked as to whether communication is possible, and the answer is negative. If so, whether or not the source operator requests recording of the message in step 708. Question is asked. Under these circumstances, a new HTML page will be service-controlled. It is generated by the Rossessa 502 and supplied to the operator terminal. This is "yes" And replace the "no" form of soft buttons, yet another by the operator Requires manual operation. Another message when the operator gives a positive answer Ask the terminal if the page exists and the message is discrete Keeping in mind that it will be considered as a cage, the question in step 709 is the operation When recognized by the user, the message is different to send the entire completed message. Effectively ask if you need to send a packet. When you answer affirmatively The next packet is sent in step 710 and control is returned to step 709. But For packets in the form of messages, the question in step 709 gets a negative answer. Continues to be sent in, resulting in the call being cleared in step 714. If the answer to the question that communication is possible in step 707 is affirmative , Control is led to step 711. Does another message exist at step 711? If a question is asked and the answer is affirmative, the message is sent in step 712. To. When all packets have been sent, the question in step 711 is answered negatively. Control is guided to step 713. In step 713, whether the call is cleared or not Question is asked, which is answered affirmatively if no further communication is required .. However, the called party tends to need to send a message. As a result, the question in step 713 is answered negatively. Finally, bidirectional communication Is completed, the question in step 713 is answered affirmatively, and the call is clicked in step 714. Be done.