JP2004363993A - Communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a connection time by enabling omitting of a negotiation procedure between terminals each equipped with a plurality of communication protocols. <P>SOLUTION: In a channel connection procedure or a PPP (point to point protocol) procedure, information indicating a communication protocol is transmitted and received, or a communication protocol is judged from a port number used in a TCP (transmission control protocol)/UDP (user datagram protocol) connection procedure, thereby previously selecting and deciding a communication protocol to be subsequently used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication terminal for transmitting and receiving packet data via a packet network, and more particularly to a communication terminal for transmitting and receiving multimedia information in real time.
[0002]
[Prior art]
The ITU-T recommendation is a communication protocol for performing multimedia information communication on a packet network such as a PDC (Personal Digital Cellular) system, an IMT-2000 (International Mobile Communication 2000) system, a broadband line (ADSL, etc.), and a wireless LAN. H. H.323 and SIP (Session Initiation Protocol) based on the IETF standard. H. H.323 and SIP are used in video phones, Internet phones using VoIP (Voice Over Internet Protocol), and the like.
[0003]
H. Terminals that perform multimedia information communication based on H.323 and SIP are respectively described below. 323 terminals and SIP terminals. H. The connection of lines based on H.323 and SIP will be described below respectively. 323 connections and SIP connections.
[0004]
A terminal that performs multimedia information communication on a packet network is usually H.264. 323 and SIP. For example, a personal computer is H.264. A terminal that supports both H.323 and SIP and uses the VoIP service is H.323. H.323 and SIP.
[0005]
Referring to FIG. A procedure when terminals supporting both H.323 and SIP perform multimedia information communication will be described. At step 121, a line connection is made, and at step 122, a PPP (Point to Point Protocol) connection is made.
[0006]
When the communication line is thus connected, negotiation is performed. In step 123, the calling terminal first generates a TCP / UDP (Transmission Control Protocol) / (User Datagram Protocol) socket for the SIP terminal. At step 124, call connection is attempted on the assumption that the called terminal is a SIP terminal.
[0007]
If the call connection is successful in step 124, the process proceeds to step 125. At step 125, the capabilities of the SIP terminal are exchanged between the calling terminal and the called terminal. At step 126, the calling terminal determines the image / voice communication mode based on the capabilities of the SIP terminal. In step 127, the calling terminal exchanges images / voices with the called terminal.
[0008]
If the call connection is not successful in step 124, the process proceeds to step 128, and the called terminal sets the H.264 connection. Assuming that the terminal is the H.323 terminal, renegotiation is performed. In step 128, the calling side terminal determines Generate a TCP / UDP socket for the H.323 terminal. In step 129, the calling terminal determines that the H.264 terminal is in the H.264 state. A call connection is established with a called terminal, which is a H.323 terminal.
[0009]
In step 130, the calling terminal communicates with the called terminal in accordance with H.264. Exchange the capabilities of the H.323 terminal. In step 131, the calling terminal determines that Based on the capabilities of the H.323 terminal, a communication mode for video / audio is determined. In step 132, the calling terminal exchanges images / voices with the called terminal.
[0010]
[Problems to be solved by the invention]
As described above, H.A. When the terminal performs multimedia information communication in accordance with both the H.323 and the SIP, after the PPP connection, the terminal first communicates with H.323. Negotiation is performed by one of H.323 and SIP, and if that fails, renegotiation is performed by another protocol. Therefore, it is necessary to send and receive many messages between terminals until the connection succeeds, and there is a disadvantage that the connection time becomes long.
[0011]
An object of the present invention is to provide a technique for reducing the number of negotiations performed with a partner terminal when performing multimedia information communication using a terminal supporting a plurality of communication protocols.
An object of the present invention is to provide a technique for shortening a connection time when performing multimedia information communication using a terminal supporting a plurality of communication protocols.
[0012]
[Means for Solving the Problems]
According to the present invention, a communication terminal transmits and receives packet data, a communication connection processing unit that performs communication connection processing, a multimedia data processing unit that performs encoding and decoding of image data and audio data, Before communicating data with a communication partner via a communication line, a negotiation for detecting a type of a communication protocol that can be used with the communication partner is performed.
[0013]
In the negotiation, information indicating a communication protocol is transmitted and received in a line connection procedure or a PPP connection procedure, or a communication protocol is determined from a port number used in a TCP / UDP connection procedure, so that the negotiation is performed thereafter. Select and determine the communication protocol in advance.
[0014]
According to the present invention, it is not necessary to perform a timeout process performed in a subsequent negotiation after a line connection, and it is possible to reduce the number of negotiations performed during connection between terminals.
[0015]
Further, by individually validating / invalidating the procedure in each layer, it is possible to automatically perform an optimal negotiation regardless of the type of terminal and the type of available network.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An example of a communication terminal according to the present invention will be described with reference to FIG. The communication terminal 100 according to the present embodiment includes a communication unit 101 that exchanges multimedia information via a packet network, a communication connection control unit 102 that individually enables / disables a procedure in each layer according to the type of the communication network, A negotiation unit 103 for performing negotiation with the other party before connecting a communication line, a PPP control unit 104 for performing a PPP connection process, a TCP / UDP control unit 105 for performing a TCP / UDP connection process; H.323 that performs call connection processing as a H.323 terminal or a SIP terminal It has a H.323 / SIP control unit 106 and a multimedia data processing unit 107 that encodes and decodes image data and audio data.
[0017]
The negotiation unit 103 performs advance negotiation before making a communication connection with the other party. First, in a line connection processing procedure, information indicating a communication protocol is transmitted and received, and an available communication protocol is detected. Alternatively, in the PPP connection procedure, information indicating a communication protocol is transmitted and received, and an available communication protocol is detected. Alternatively, the communication protocol is determined from the port number used in the TCP / UDP connection procedure.
[0018]
In this way, in the line connection processing, the PPP connection processing, and the TCP / UDP connection processing, the type of the communication protocol that can be understood by the other party is acquired in advance, so that repeated negotiations are avoided.
[0019]
The communication terminal of this example is not only a communication network with a line connection like the IMT-2000 system, but also a communication network without a line connection like a broadband environment, and a line connection and a PPP connection like a wireless LAN. It is also possible to use a communication network without accompanying. That is, the communication terminal of this example may be an IMT-2000 system terminal, a terminal connected to a broadband line, or a terminal connected to a wireless LAN.
[0020]
The communication connection control unit 102, based on the communication method of the present communication terminal, omits the line connection if it is unnecessary, and omits it if the line connection and the PPP connection are unnecessary. Perform connection processing.
[0021]
With reference to FIG. 2, the flow of a connection process between communication terminals according to the present invention will be described. In step 011, normal line connection processing is performed, and connection of the calling side (own side) terminal from the calling side (own side) terminal to the called side (other side) terminal in the call control layer. Send capability (H.323 / SIP). In step 012, it is determined whether or not the terminal on the called side (other side) can understand the connection procedure (H.323 / SIP) of the terminal on the calling side (self side). If the terminal on the called side (other side) can understand the connection procedure of the terminal on the calling side (own side), the process proceeds to step 013, and the terminal on the called side (other side) is connected to the calling side (local side) If the connection procedure of the terminal cannot be understood, the process proceeds to step 016.
[0022]
In step 013, the call control layer determines a communication protocol (H.323 / SIP) to be used for connection. That is, the communication protocol (H.323 / SIP) that can be used by the terminal is exchanged using the call control message, and the communication protocol type (H.323 / SIP) used for the connection is determined. In step 014, normal PPP connection processing is performed. In step 015, normal TCP / UDP connection processing is performed. In step 211, media communication of audio and video is started using the determined communication protocol (H.323 / SIP).
[0023]
At step 016, normal PPP connection processing is performed. The connection capability (H.323 / SIP) of the terminal on the calling side (self side) is transmitted by the PPP layer from the terminal on the calling side (self side) to the terminal on the called side (other side). Here, an NCP (Network Control Protocol) message which is a PPP connection message may be used.
[0024]
In step 017, it is determined whether or not the terminal on the called side (other side) can understand the connection procedure of the terminal on the calling side (self side). If the terminal on the called side (other side) can understand the connection procedure of the terminal on the calling side (own side), the process proceeds to step 018, and the terminal on the called side (other side) is connected to the calling side (local side). If the connection procedure of the terminal cannot be understood, the process proceeds to step 019.
[0025]
At step 018, the PPP layer determines a communication protocol (H.323 / SIP) to be used for connection. That is, the communication protocol (H.323 / SIP) that can be used by the terminal is exchanged, and the communication protocol type (H.323 / SIP) used for the connection is determined. Here, an NCP (Network Control Protocol) message which is a PPP connection message may be used. Next, the process proceeds to step 015.
[0026]
In step 019, normal TCP / UDP connection processing is performed. In step 020, the communication protocol (H.323 / SIP) used for the connection is determined in the TCP / UDP layer. That is, the communication protocol type (H.323 / SIP) to be used for connection is determined according to the port number to be used, and the process proceeds to step 021.
[0027]
In this example, in line connection processing, PPP connection processing, and TCP / UDP connection processing, The use of the H.323 application or the SIP application is negotiated and determined in advance.
[0028]
Therefore, the renegotiation (123, 124, 128, 129) of the communication protocol performed by the conventional communication terminal in the application layer can be omitted, and the connection time can be reduced.
[0029]
Referring to FIG. 3, using the connection procedure of the present invention, A process flow until the H.323 application or the SIP application is connected to each other will be described. Steps 041 to 050 correspond to steps 011 to 020 in FIG. First, in step 041, the terminal on the calling side (self side) communicates with the bearer capability (BC), the lower layer compatibility (LLC), and the higher layer compatibility (HLC) by a protocol (H. H.323 / SIP), and transmits it to the called (terminal) terminal using a call control message. Similarly, the calling terminal can also receive a bearer capability (BC) in which a protocol (H.323 / SIP) capable of communication is set, a lower layer consistency (LLC), and a higher Receive a call control message including a layer consistency (HLC).
[0030]
Next, in step 042, the terminal on the calling side (own side) transmits the bearer capability (BC), the low layer compatibility (LLC), and the high layer compatibility (BC) in the call control message from the called terminal. It is determined whether or not the HLC) has the same settings as those of the calling side.
[0031]
If the bearer capability (BC), lower layer compatibility (LLC), and higher layer compatibility (HLC) in the call control message from the called terminal include the same settings as those of the calling side, the step is performed. The process proceeds to 043, and if there is no similar setting, the process proceeds to step 046.
[0032]
In step 043, the calling terminal determines according to the identifiers included in the bearer capability (BC), the lower layer compatibility (LLC), and the higher layer compatibility (HLC) in the call control message from the called terminal. And the communication protocol (H.323 / SIP). In step 044, normal PPP connection processing is performed.
[0033]
In step 045, a socket is generated with the port number used in the selected communication protocol, TCP / UDP connection is performed, and the process proceeds to step 051.
In step 046, the terminal on the calling side performs a normal PPP connection process, performs a setting indicating a protocol (H.323 / SIP) with which communication is possible, and uses the NCP message in the PPP message. Then, the call is transmitted to the terminal on the called side (the other side). The calling terminal similarly receives, from the called terminal, the NCP message in the PPP message indicating the protocol (H.323 / SIP) with which communication is possible.
[0034]
In step 047, the terminal on the calling side (self side) determines whether or not the NCP message in the PPP message from the terminal on the called side includes the same setting as the setting on the calling side. If there is a setting similar to that of the calling side in the NCP message from the called terminal, the process proceeds to step 048; otherwise, the process proceeds to step 049.
[0035]
In step 048, the calling terminal selects a communication protocol (H.323 / SIP) according to the identifier included in the NCP message from the called terminal, and proceeds to step 045.
[0036]
In step 049, H. A socket is generated with a port number used by both H.323 and SIP, and TCP / UDP connection processing is performed. When using TCP, a connection is established. When using UDP, the following H.264 is used. A part of a call control message used in H.323 / SIP (RAS message in H.323, INVITE message in SIP, etc.) is transmitted. Next, in step 050, a communication protocol type (H.323 / SIP) is selected based on the port number received from the called terminal, and the process proceeds to step 051.
[0037]
In step 051, the calling terminal determines that the communication protocol type is H.264. It is determined whether it is H.323 or SIP, and an application to be used thereafter is selected based on the result of the determination. If the communication protocol type is H. If it is H.323, H.323 of steps 052 to 055 is executed. If the communication protocol type is SIP, negotiation of SIP in steps 056 to 059 is performed to complete the connection.
[0038]
H. of steps 052 to 055. The H.323 negotiation will be described. At step 052, The H.323 terminal performs call connection processing. At step 053, 323 terminals are exchanged. In step 054, the communication mode of the image and sound is determined. In step 055, image and voice communication is performed. Similarly, the negotiation of SIP in steps 056 to 059 will be described. In step 056, a call connection process of the SIP terminal is performed. In step 057, the capabilities of the SIP terminal are exchanged. In step 058, the communication mode of the image and sound is determined. In step 059, image and voice communication is performed.
[0039]
With reference to FIG. 4, the line connection processing 061 of step 011 and step 041 will be described in detail. FIG. 4 shows a call connection message exchanged between terminals during line connection. First, a Setup message is transmitted from a calling terminal to a called terminal. Upon receiving the Setup message, the called terminal transmits a CallProceeding message, an Alert message, and a Connect message to the calling terminal. When the calling terminal receives the Connect message from the called terminal, a line connection is established.
[0040]
In this example, the information of the communication protocol type to be used hereinafter is transmitted by using the bearer capability, the lower layer compatibility, and the higher layer compatibility included in the Setup message, CallProceeding message, and Alert message of the call control message. Perform processing.
[0041]
Next, the PPP connection processing of steps 016 and 046 will be described in detail with reference to FIG. FIG. 5 shows a PPP message exchanged between terminals during PPP connection. First, an LCP (Link Control Protocol) message is exchanged between a calling terminal and a called terminal, then an Authentication message is exchanged, and then an NCP (Network Control Protocol) message is exchanged similarly. The connection 062 of the PPP is established.
[0042]
In this example, a connection process is performed by using the NCP message of the PPP message to transmit information of a communication protocol type to be used later. Subsequent negotiations may be performed using the H.264 method described above. H.323 or SIP can be transmitted by preceding negotiation, and the number of subsequent negotiations can be reduced.
[0043]
The communication terminal according to the present invention has a 323 and SIP have been described. However, H. et al. H.323 and SIP are examples, and can support other protocols, and are not limited thereto.
[0044]
In the above-described example, the case where a communication network with a line connection is used as in the IMT-2000 system has been described. The present invention can be applied to a communication network that does not involve line connection, such as a broadband environment. In this case, the procedure of line connection may be omitted from the above procedure.
[0045]
Further, the present invention is applicable to a communication network that does not involve a line connection and a PPP connection, such as a wireless LAN. In this case, the line connection procedure and the PPP connection procedure may be omitted from the above procedure.
[0046]
According to the present invention, not only a communication network with a line connection such as the IMT-2000 system but also a communication network without a line connection such as a broadband environment further includes a line connection and a PPP connection like a wireless LAN. Even in a communication network that does not have the above, the number of subsequent negotiations can be reduced by the same procedure as described above.
Although the embodiments of the present invention have been described above, those skilled in the art will understand that the present invention is not limited to the above-described embodiments, and that various modifications can be made within the scope of the claims.
[0047]
【The invention's effect】
By using the above connection procedure, the negotiation time of a terminal equipped with a plurality of communication protocols can be reduced.
Also, by enabling / disabling the procedure in each layer individually according to the type of network, it is possible to flexibly cope with any type of network and to shorten the above-described negotiation time. it can.
[0048]
Further, by enabling / disabling the procedure in each layer individually according to the type of terminal configuration, it is possible to flexibly cope with any terminal configuration, and to shorten the negotiation time described above. be able to.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a communication terminal according to the present invention.
FIG. 2 is a diagram showing a processing flow of a connection procedure of a communication terminal according to the present invention.
FIG. 3 shows a communication terminal according to the present invention. FIG. 9 is a diagram illustrating a flow of processing until the H.323 application or the SIP applications are connected to each other.
FIG. 4 is a diagram showing an example of a call connection message exchanged between terminals when a line is connected.
FIG. 5 is a diagram illustrating an example of a PPP message exchanged between terminals during PPP connection.
FIG. FIG. 8 is a diagram showing a procedure when the H.323 / SIP terminal connects using a communication line.
[Explanation of symbols]
101 communication unit, 102 communication connection control unit, 103 negotiation unit, 104 PPP control unit, 105 TCP / UDP control unit, 106 H. H.323 / SIP control unit, 107 ... Multimedia data processing unit

Claims (10)

A communication unit that transmits and receives packet data, a communication connection processing unit that performs communication connection processing, and a multimedia data processing unit that performs encoding and decoding of image data and audio data. A communication terminal for performing negotiation for detecting a type of a usable communication protocol with a communication partner before exchanging data with the communication terminal. The communication terminal according to claim 1, wherein in the negotiation, a communication protocol usable using an information element including a bearer capability, a lower layer compatibility, and a higher layer compatibility, which are call control messages of a mobile communication network. A communication terminal for detecting a type. 3. The communication terminal according to claim 1, wherein the negotiation uses NCP (Network Control Protocol) information that is a PPP connection message. 4. The communication terminal according to claim 1, wherein the negotiation uses TCP / UDP connection message information. 5. The communication terminal according to claim 1, wherein the communication connection processing unit switches between valid and invalid communication connection procedures based on a capability of a communication partner, and sequentially falls back to an appropriate procedure. 6. A communication terminal, characterized in that: 5. The communication terminal according to claim 1, wherein the communication connection processing unit switches between valid and invalid communication connection procedures based on a type of a network to be used, and sequentially falls back to an appropriate procedure. A communication terminal. 5. The communication terminal according to claim 1, wherein the communication connection processing unit switches between valid and invalid communication connection procedures based on the configuration of the communication terminal, and sequentially falls back to an appropriate procedure. A communication terminal. 2. The communication terminal according to claim 1, wherein the communication connection processing unit includes a PPP connection process, a TCP / UDP connection process, and an H.264 connection process. 323 / SIP A communication terminal that sequentially performs necessary processing among SIP connection processing. Detecting a usable communication protocol by exchanging connection capability between the communication partner and the terminal in the call control layer, and detecting an available communication protocol by exchanging connection capability between the communication partner and the terminal in the PPP layer A program for causing a computer to execute the steps and a step of detecting a usable communication protocol from a port number used in a TCP / UDP layer. A recording medium on which the program according to claim 9 is recorded.

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