JP2000032090A - System and method for detecting fault of communication opposite party - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the system and method for detecting a fault of a communication opposite party by which a fault of a client is detected at opening of a session without awaiting fault monitoring by non-reply monitoring or non- communication monitoring. SOLUTION: A session identifier storage section 221 stores a client AP identifier of a client AP211. When the client AP221 sets up communication with a server host 1, the client AP221 sends session identification information consisting of the client AP identifier and an IP address of the client AP to the server host 1. A session identification information storage section 121 stores the received session identification information. A server AP111 collates the client AP identifier and the IP address of the received session identification information with the client AP identifier and the IP address of the session identification information storage section 121 and recognizes occurrence of a fault when they are coincident.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication partner failure detection system and method for detecting a failure of a communication partner during communication.

[0002]

2. Description of the Related Art In a conventional communication system based on the TCP / IP protocol, a communication partner failure detection system and method for detecting a failure of a communication partner during communication is performed by communication failure monitoring such as non-response monitoring or non-communication monitoring. It was to detect the obstacle of the other party.

[0003]

However, in the communication partner failure detection system and method shown in the above-mentioned conventional example, the failure of the communication partner cannot be detected without waiting for a predetermined time, and the monitoring time interval is shortened. Then, there is a problem that traffic increases.

Further, in the conventional communication partner failure detection system and method, when the client AP recovers and reconnects after the failure, the server AP cannot distinguish it from the session before the failure of the client AP. There is a problem that the session is recognized as a session with another client AP, and complicated processing is required for the server AP to synchronize with the client AP.

An object of the present invention is to detect a failure of a communication partner during communication in a communication system based on the TCP / IP protocol faster than waiting for a certain period of time by monitoring a communication failure such as non-response monitoring or non-communication monitoring. It is an object of the present invention to provide a communication partner failure detection system and method capable of performing the above.

[0006]

According to an aspect of the present invention, a server host having a single server AP and a plurality of client APs connected to the server host via a network device are provided. Client AP for identifying a plurality of client APs in a communication system having a single client host
First client AP identifier storing means for storing an identifier; and client AP identifier transmitting means for transmitting the client AP identifier stored in the client AP identifier storing means to the server host when the client AP establishes communication with the server host. Has the server host
Second client AP identifier storage means for storing the client AP identifier when the client AP identifier transmitted by the client AP identifier transmission means is received, and client A when the client AP identifier transmitted by the client AP identifier transmission means is received.
Collating means for collating the P identifier with the client AP identifier stored in the second client AP identifier storing means; and the client AP identifier transmitted by the AP identifier transmitting means by the collating means to the second client A
A failure detecting unit that recognizes that a failure has occurred when the client AP identifier matches the client AP identifier stored in the P identifier storage unit.

According to a second aspect of the present invention, a single server AP is provided.
In a communication system having a server host having a plurality of client APs connected to the server host via a network device and having a plurality of client APs, a client AP identifier of the client AP for identifying the plurality of client APs is stored. A client AP identifier storage unit; and a session identification information transmitting unit configured to transmit session identification information including a client AP identifier and an IP address of the client AP to the server host when the client AP establishes communication with the server host. The host receives the session identification information transmitted by the session identification information transmitting unit, and stores the session identification information transmitted by the session identification information transmitting unit. Collating means for collating the client AP identifier and IP address of the session identification information with the client AP identifier and IP address of the session identification information stored in the session identification information storage means; Client AP of the identified session identification information
A failure detecting unit that recognizes that a failure has occurred when the identifier and the IP address match the client AP identifier and the IP address of the session identification information stored in the session identification information storage unit.

According to a third aspect of the present invention, a plurality of server APs are provided.
In a communication system having a server host having a plurality of client APs connected to the server host via a network device and having a plurality of client APs, a client AP identifier of the client AP for identifying the plurality of client APs is stored. A client AP identifier storage unit; and a session identification information transmitting unit configured to transmit session identification information including a client AP identifier and an IP address of the client AP to the server host when the client AP establishes communication with the server host. A session identification information storage unit that stores the session identification information and the PORT number of the server AP with which the host has communicated when receiving the session identification information transmitted by the session identification information transmission unit; When the session identification information transmitted by the identification information transmitting means is received, the client AP identifier and the IP address of the session identification information, the PORT number of the server AP with which the communication is made, and the session identification information stored in the session identification information storage means. Means for collating the client AP identifier of the client with the IP address and the PORT number of the server AP as the communication partner, and the client AP identifier, IP address and communication of the session identification information transmitted by the collation means by the session identification information transmitting means. The PORT number of the partner server AP is the client AP identifier and the IP address of the session identification information stored in the session identification information storage means, and the PO of the server AP as the communication partner.
A failure detecting means for recognizing that a failure has occurred when the RT number matches the RT number.

According to a fourth aspect of the present invention, a single server AP is provided.
Client A for identifying a plurality of client APs in a communication method having a server host having a plurality of client APs connected to the server host by a network device and having a plurality of client APs
A first client AP identifier storing step of storing a P identifier in a first client AP identifier storage unit, and a client AP identifier for transmitting the client AP identifier of the client AP to the server host when the client AP establishes communication with the server host Sending step;
The second client A stored in the second client AP identifier storage unit when the client AP identifier transmitted in the client AP identifier transmitting step is received.
A P identifier storage step, and a collation step of collating the client AP identifier with the client AP identifier stored in the second client AP identifier storage step when receiving the client AP identifier transmitted in the client AP identifier transmission step, A failure detecting step of recognizing that a failure has occurred when the client AP identifier transmitted by the client AP identifier transmitting step by the collating step matches the client AP identifier stored by the second client AP identifier storing step. It is characterized by.

[0010] The invention according to claim 5 is a single server AP.
A communication method comprising: a server host having a plurality of client hosts connected to the server host via a network device and including a plurality of client APs.
A client AP identifier storing step of storing a client AP identifier of the client AP for identifying a plurality of client APs in a client AP identifier storage unit; and a client AP identifier of the client AP and I when the client AP establishes communication with a server host.
A session identification information transmitting step of transmitting session identification information including a P address to the server host, and a session identification information storage step of storing the session identification information storage unit when the session identification information transmitted in the session identification information transmission step is received. A client AP identifier and an IP address of the session identification information when the session identification information transmitted in the session identification information transmitting step is received, and a client AP identifier and an IP address of the session identification information stored in the session identification information storing step. A client AP identifier and an IP address of the session identification information transmitted by the session identification information transmitting step by the collation step. And having a recognizing fault detecting step that a failure has occurred when a match client AP identifier and IP address of the session identification information stored in step.

[0011] According to a sixth aspect of the present invention, a plurality of server APs are provided.
A communication method comprising: a server host having a plurality of client hosts connected to the server host via a network device and including a plurality of client APs.
A client AP identifier storing step of storing a client AP identifier of the client AP for identifying a plurality of client APs in a client AP identifier storage unit; and a client AP identifier of the client AP and I when the client AP establishes communication with a server host.
A session identification information transmitting step of transmitting session identification information including a P address to the server host; and a PORT of the server AP with which the session identification information and the communication partner have been transmitted when the session identification information transmitted in the session identification information transmission step is received. A session identification information storing step in which the session identification information is stored in the session identification information storage unit; and a client AP identifier, an IP address, and a communication partner of the session identification information when the session identification information transmitted in the session identification information transmitting step is received. A collation step of collating the PORT number of the server AP with the client AP identifier of the session identification information stored in the session identification information storage step, the IP address, and the PORT number of the server AP that is the communication partner; The client ID of the session identification information stored in the session identification information storing step in which the client AP identifier and the IP address of the session identification information transmitted in the session identification information transmitting step in the collation step and the PORT number of the server AP as the communication partner are stored in the session identification information storing step. A failure detecting step of recognizing that a failure has occurred when the identifier, the IP address, and the PORT number of the server AP as the communication partner are matched.

[0012]

Next, a communication system and a method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a communication partner failure detection system as one embodiment of the present invention. A communication partner failure detection system according to an embodiment of the present invention includes: a server host 1;
It has a client host 2 and a network device 3 connecting them.

The server host 1 has a data processing device 11 that operates under program control of the server host 1 and a plurality of storage devices 12 that store information on the server host 1. The data processing device 11 includes a server AP 111
And a TCP / IP connection control unit 112 and a session identification information control unit 113. Storage device 1
2 has a session identification information storage unit 121.
The session identification information storage unit 121 has a session identification management table 1211.

The client host 2 has a data processing device 21 that operates under program control of the client host 2 and a storage device 22 that stores information on the client host 2. The data processing device 21 has a client AP 211 and a TCP / IP connection control unit 212. The client AP 211 has a client AP session control unit 2111. The storage device 22 has a session identifier storage unit 221. The network device 3 performs communication using a TCP / IP protocol such as a LAN and a WAN.

First, the outline of the present invention will be described. As shown in FIG. 1, when a session is active between the server host 1 and the client host 2 in the network configured by the server host 1 and the client host 2 according to the communication system of the TCP / IP protocol, If the client host 2 goes down in the no-communication state, the server AP 111 performs no-response monitoring or no-communication monitoring, and waits for a certain period of time to detect a failure of the partner client host. After restarting, the same client AP 211 and the same server AP 111 of the server host 1 may make a session opening request as before the down.

Therefore, in the session between the server AP 111 and the client AP 211, if the same session identification information is always managed by the server AP 111, the client host 2 that has gone down within the monitoring time is restarted, and When a session establishment request is made between the same client AP 211 and the same server AP 111 as the server host 1, the server AP 111 receives the same session identification information as the session identification information being managed from the client host 2, and contradicts the session identification information. Has occurred, it can be determined that "a failure has occurred in the partner client host 2 and reconnection has been made after recovery." That is,
The server AP 111 can detect a failure of the partner client host 2 faster than detecting a failure after waiting for a certain period of time in failure monitoring by non-response monitoring or non-communication monitoring. At this time, the server AP 111 holds a new session opening request, holds data transmission / reception information of an active session, releases session information such as other TCP connections, and resolves inconsistency due to a failure. By opening a session with the held new session opening request, the server AP 111 detects the failure of the partner client AP 211 and synchronizes with the data transmission / reception information.

In the communication partner failure detection system based on the TCP / IP protocol, the PORT of the client AP is used.
In general, the number is automatically assigned when a connection is established. Since the server AP may be a different client AP even if the partner PORT number is the same, the server AP can uniquely identify the partner client AP. The fact that the PORT number cannot be used as the session identification information, and that the server AP has P as the session identification information that can uniquely identify the partner client AP
To use the ORT number, it is sufficient to fix the PORT number. However, since the existing TCP / IP protocol is affected, the TCP / IP referred to in the OSI layer is affected.
In a higher-layer application layer than a protocol, a server AP can manage session identification information that can uniquely identify a partner client AP.

Specifically, the client AP 211 includes all the client APs 21 on the client host 2.
Only one client AP identifier capable of uniquely identifying 1 is defined in advance in the client AP identifier storage unit 221, and the client AP 211 notifies the server AP 111 of the client AP identifier at the time of opening a session with the server AP 111. The server AP 111 uses the client AP identifier notified from the client AP 211 at the time of opening the session, and stores all sessions between the server AP 111 on the server host 1 and the client AP 211 on the client host 2 until the session is released. The session identification information is managed in the session identification management table 1211 provided in the storage device 12 as session identification information that can be uniquely identified.

The storage device 22 includes a client AP identifier storage unit 221 that stores a client AP identifier that is defined in advance so as to be unique on the client host 2, one for each client AP 211 on the client host 2. ing.

Data processing device 2 of client host 2
1 includes a client AP 211 and a TCP / IP connection control unit 212. Client AP
211 is a client AP session control unit 2111
It has. Client AP session control unit 21
11 performs the following session control to communicate with the server AP111. TCP / IP connection control unit 2
12 is notified of a TCP connection establishment request. TCP
Upon receiving a notification of completion of the establishment of the TCP connection from the / IP connection control unit 212, the client AP identifier storage unit 221
Using the TCP / IP connection control unit 212, the client AP identifier 211
Notify. If the received data notified from the TCP / IP connection control unit 212 is a notification of a response to the notification of the client AP identifier from the partner server AP 111, it is considered that the session establishment with the partner server AP 111 has been completed.

TCP / IP connection control unit 212
Performs overall control of the TCP connection according to the TCP / IP protocol. When the TCP connection establishment is completed, the client AP session control unit 2111
Notification of completion of P connection establishment is performed. When the release of the TCP connection is completed, the client AP session control unit 2111 is notified of the completion of the release of the TCP connection.

The storage device 12 includes a session identification information storage unit 121 and a server session identification management table 12.
11 (hereinafter referred to as SSMT). The session identification information storage unit 121 stores the POR of the server AP111.
The T number, the client AP identifier received from the client AP 211, and the partner client host 2
Is stored in the server session identification management table 1211 as one piece of session identification information.

The data processing device 11 includes a server AP 111
, A TCP / IP connection control unit 112, and a session identification information control unit 113. Server AP
111 includes a server AP session control unit 1111. The server AP session control unit 1111 performs the following session control to communicate with the client AP 211.

In the session opening process, after the TCP connection is opened, the TCP / IP connection control unit 112 sends the client A
When a notification of data reception of the P identifier is received, TCP /
For the IP connection control unit 112, the IP address of the partner client host 2 of the TCP connection that has received this data and the PO address of the partner client AP 211
An RT number is requested, and the PORT number of the server AP 111, the client AP identifier received from the client AP 211, the IP address of the partner client host 2 received from the TCP / IP connection control unit 112, and the RT number received from the TCP / IP connection control unit 112 The registration request is notified to the session identification information control unit 113 using the PORT number of the partner client AP 211 as one session identification information. When receiving the notification of the completion of the registration of the session identification information from the session identification information control unit 113, it notifies the partner client AP 211 of a response to the client AP identifier notification, and regards the completion of the session establishment with the partner client AP 211.

In the session release processing, if a session release request is sent from the session identification information control unit 113, the data transmission / reception information is held.
If the request is a session release request from a device other than 13, the data transmission / reception information is deleted. Thereafter, a TCP connection release request is notified to the TCP / IP connection control unit 112,
Upon receiving the notification of the completion of the release of the TCP connection from the TCP / IP connection control unit 112, the control unit 113 notifies the session identification information control unit 113 of a session identification information deletion request. Upon receiving the notification of the completion of the deletion of the session identification information from the session identification information control unit 113, it is regarded that the session release with the partner client AP 211 is completed.

When a registration request is received from the server AP session control unit 1111, the session identification information control unit 113 sets the PO of the server AP 111 of the session identification information.
RT number, client AP identifier, IP address of partner client host 2, partner client AP
A session identification management table 1211 is created using the PORT number 211 and the session identification information storage unit 121.
And notifies the server AP session control unit 1111 of the completion of the registration of the session identification information. When a deletion request is issued from the server AP session control unit 1111, the PORT number of the server AP 111 of the session identification information,
The session identification management table 1211 is searched from the session identification information storage unit 121 using the IP address of the partner client host 2 and the PORT number of the partner client AP 211 as keys. If the session identification management table 1211 can be detected, it is deleted from the session identification information storage unit 121 and the server AP session control unit 111
1 is notified that the session identification information has been deleted. If the PORT number of the server AP 111, the client AP identifier, and the IP address of the partner client host 2 of the SSMT-1 created with the session identification information requested to be registered by the server AP session control unit 1111 are the same. If “−2” has already been stored in the session identification information storage unit 121, the server AP session control unit 1111 is notified of a request to release the stored SSMT-2 session. The server AP session control unit 1111 sends the SSM
When the session identification information deletion request of T-2 is received, the session identification information is deleted from the session identification information storage unit 121, and when the completion of the deletion of the session identification information is notified, the SSMT-1 created by the new session establishment request is replaced with the session identification information. Stored in the storage unit 121, the server AP session control unit 1
111 is notified that the session identification information registration has been completed.

TCP / IP connection control unit 112
Performs overall control of the TCP connection according to the TCP / IP protocol. When the establishment of the TCP connection is completed, the server AP session control unit 1111 is notified of the completion of the establishment of the TCP connection. When the release of the TCP connection is completed, the server AP session control unit
A P connection release completion notification is performed. Next, with reference to FIGS. 1, 2, 3, 4, 5, 6, 7, and 8, a communication system having a communication partner fault detection system as one embodiment of the present invention will be described. The overall operation will be described in detail.

Client AP session control section 211
When recognizing the establishment of the TCP connection (steps A1, D1 and D2), the client AP2 uses the TCP / IP connection control unit 212 to define the client AP2 previously defined in the client AP identifier storage unit 221.
11 of the client AP identifier to the partner server AP (steps A2, D3, D4 and D5). The client AP session control unit 2111 uses TCP / IP
If the received data notified from the connection control unit 212 is a notification of a response to the notification of the client AP identifier from the partner server AP (step D12), it is considered that the session establishment with the partner server AP is completed (step A3).

[0029] The server AP session control unit 1111 includes:
When a notification of data reception of the client AP identifier from the partner client AP 211 is received from the TCP / IP connection control unit 112 (step D5), the TCP
/ IP connection control unit 112 transmits the data of the client AP identifier to the TCP connection,
A request is made for the IP address of the partner client host 2 and the PORT number of the partner client AP 211 (steps D6 and D7), and the PORT number of the server AP 111, the client AP identifier received from the client AP 211, and the TCP / IP connection control unit 11
The IP address of the partner client host 2 received from the client ID 2, the PORT number of the partner client AP 211 received from the TCP / IP connection control unit 112, and the session identification information registration request are notified to the session identification information control unit 113 (step D8). ).

When the session identification information control section 113 receives the session identification information registration request notification from the server AP session control section 1111 (step D8), the client identification information received from the server AP session control section 1111 and the partner client host 2 An SSMT is created using the IP address of the client and the PORT number of the partner client AP 211 (step B1).

The session identification information control unit 113
When the MT is created, the SSMT registered in the session identification information storage unit 121 is searched using the PORT number of the SSMT server AP 111, the client AP identifier, and the IP address of the partner client host 2 as keys (step B2). ). If the SSMT cannot be detected, the created SSMT is stored in the session identification information storage unit 12.
1 and notifies the server AP session control unit 1111 of the completion of the registration of the session identification information (step B4).
And D9). Server AP session control unit 1111
When receiving the notification of the completion of registration of the session identification information from the session identification information control unit 113 (step D9),
Using the CP / IP connection control unit 112, a response to the client AP identifier notification from the partner client AP 211 is notified (steps D10, D11 and D12), and it is regarded that the session establishment with the partner client AP 211 has been completed (step B5).

The server AP session control unit 1111 includes:
When releasing a session with the client AP 211,
In the case of a session release request from the session identification information control unit 113, data transmission / reception information is held, and in the case of a session release request from a source other than the session identification information control unit 113, the data transmission / reception information is deleted (steps C1 and C2). After that, the server AP session control unit 1111
Sends to the TCP / IP connection control unit 112 the I / O of the partner client host 2 of the TCP connection to be released.
It notifies the P address, the PORT number of the client AP 211 of the TCP connection to be released, and the TCP connection release request (step E1).

TCP / IP connection control unit 112
Receives the notification of the TCP connection release request from the server AP session control unit 1111 (step E
1) The TC corresponding to the IP address of the partner client host 2 received from the server AP session control unit 1111 and the PORT number of the partner client AP 211
Releases the P connection, and upon completion of the release, the server AP
The session control unit 1111 is notified of the normal completion of the release of the TCP connection (step E2).

The server AP session control unit 1111 includes:
Upon receiving a TCP connection release normal completion notification from the TCP / IP connection control unit 112 (step E
2) Recognize that the TCP connection has been released (step C)
3).

The server AP session control unit 1111 includes:
Upon recognizing that the TCP connection has been released, the session identification information control unit 113 informs the session identification information control unit 113 of the PORT number of the server AP 111, the IP address of the partner client host 2 of the released TCP connection, the PORT number of the partner client AP 211 of the released TCP connection, Notification of the identification information deletion request is performed (step E
3).

When the session identification information control unit 113 receives the notification of the session identification information deletion request from the server AP session control unit 1111 (step E3), the PORT number of the server AP 111 received from the server AP session control unit 1111 and The SSMT is searched from the session identification information storage unit 121 using the IP address of the partner client host 2 and the PORT number of the partner client AP 211 as keys. If the SSMT can be detected, the SSMT is deleted from the session identification information storage unit 121, and the completion of the deletion of the session identification information is notified to the server AP session control unit 1111 (steps C4 and E4). Upon receiving the session identification information deletion completion notification from the session identification information control unit 113 (step E4), the server AP session control unit 1111 receives the notification from the session identification information control unit 113 (step E4).
It is considered that the session release with No. 11 is completed.

The session identification information control unit 113 uses the PORT number of the SSMT-1 server AP 111 created by the new session opening request, the client AP identifier, and the IP address of the partner client host 2 as a key to set the session identification information. SSMT-
2 can be detected, the request for releasing the session is sent to the server A using the PORT number of the server AP 111, the IP address of the partner client host 2, and the PORT number of the partner client AP 211 stored in the SSMT-2.
Notify the P session control unit 1111 (step B3
And B6). Due to SSMT-2 session release processing,
The server AP session control unit 1111 sends the SSMT-
2 is received (step E3), the request is deleted from the session identification information storage unit 121,
When the notification of the completion of the deletion of the session identification information is given (step E4), the SSMT created by the new session establishment request is sent.
-1 is stored in the session identification information storage unit 121,
The server AP session control unit 1111 is notified of the completion of the registration of the session identification information (steps B4 and D9).

Next, an operation example in the embodiment of the present invention will be described using a specific example. The server host 1 has an IP address of SIP, and the server AP 111 has a PORT number of S.
In PROT, the client host 2 has the IP address of CIP and the client AP 211
It is assumed that the identifier is CAP and communication is performed between the client AP 211 and the server AP 111.

Client AP 211 and server AP 11
1 and there is no session, the client AP 211
Attempt to open a session with the server AP 111 from the client AP 211
When a TCP connection is established with the PORT number of CPORT-A and the client AP identifier of the CAP is received from the client AP 211, as shown in FIG.
The SSMT-A is created from the PORT, the CAP, the CIP, and the CPORT-A, and the session identification information storage unit 121 is created.
To memorize.

At this time, when a non-communication state is set, non-communication monitoring is performed, and if data transmission / reception is not performed even after waiting for a predetermined time, it is recognized that the partner client host 2 has gone down. While monitoring non-communication and waiting for a certain period of time, it cannot recognize that the partner client host 2 has gone down.
In the meantime, if the client host 2 recovers and attempts to establish a session with the server AP 111 from the client AP 211, the server AP 111 establishes a TCP connection with the PORT number of the client AP 211 being CPORT-B, and establishes a C connection from the client AP 211.
Upon receiving the client AP identifier of the AP, as shown in FIG. 8, SPORT, CAP, CIP, CPOR
SSMT-B is created by TB. However, SSMT-
B is S stored in the session identification information storage unit 121.
SPOR which is the same session identification information as SMT-A
Since T, CAP, and CIP are stored, the server AP 111 detects that the partner client host has gone down due to a failure but has been restored. So SSMT
-The data transmission / reception information is held to synchronize with the SSMT-B session at the time of releasing the session managed by A.
After the MT-A session is released, the SSMT-A is deleted from the session identification information storage unit 121, and the SSMT-B is stored in the session identification information storage unit 121. In this way, the server AP 111 can also perform synchronization control while detecting a failure of the partner client AP 211.

In the embodiment of the present invention shown in FIG.
Although the protocol of CP / IP was used, the present invention
Since it is only necessary to uniquely identify the session on the computer, the session can be implemented in the application layer in the OSI layer, and does not depend on a protocol in a lower layer than the application layer. Therefore, embodiments of the present invention are based on TCP /
It is possible to use protocols other than the IP protocol.

[0042]

As is apparent from the above description, according to the communication partner fault detection system and method of the present invention, a fault is detected after waiting for a predetermined time in the fault monitoring by the non-response monitoring or the non-communication monitoring. When a session is opened, if the partner server AP is the same, the same session information is always used, and when a session is opened twice, it can be detected that a failure has occurred. It is possible to detect a failure of the partner client at the time of opening a session without waiting for the failure monitoring by.

Further, according to the communication partner failure detection system and method of the present invention, when the client recovers after the occurrence of the failure and reconnects, the request of the client is rejected in order to eliminate the inconsistency on the server side. It is possible to accept without. This is because the server AP has requested the client A and the other client A of the session being managed.
Because it is possible to recognize that P is the same, it is possible to judge that the session under management is abnormal, and thus the inconsistency in the server AP can be resolved by releasing only the session information under management.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a communication system having a communication partner fault detection system as one embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the communication partner failure detection system of FIG. 1;

FIG. 3 is another flowchart for explaining the operation of the communication partner failure detection system of FIG. 1;

FIG. 4 is another flowchart for explaining the operation of the communication partner failure detection system of FIG. 1;

FIG. 5 is a sequence diagram for explaining an operation of the communication partner failure detection system of FIG. 1;

FIG. 6 is another sequence diagram for explaining the operation of the communication partner fault detection system of FIG. 1;

FIG. 7 is a diagram for explaining a specific example of the operation of the communication partner failure detection system of FIG. 1;

FIG. 8 is another diagram for explaining a specific example of the operation of the communication partner fault detection system of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 server host 2 client host 3 network device 11 data processing device 12 storage device 21 data processing device 22 storage device 111 server AP 112 TCP / IP connection control unit 113 session identification information control unit 121 session identification information storage unit 211 client AP 212 TCP / IP connection control unit 221 session identifier recording unit 1111 server AP session control unit 1211 session identification management table

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoya Kondo 1-18-6 Shinkiba, Koto-ku, Tokyo Japan Electric Software Co., Ltd. F-term (reference) 5K032 AA02 AA06 BA04 CC09 DA01 DB19 EA04 EC04 5K035 AA01 AA07 BB02 CC01 DD01 EE02 FF01 GG02 KK01 5K042 AA08 BA10 CA05 CA11 CA12 DA32 FA15 GA01 GA11 LA12

Claims (6)

[Claims] 1. A communication system comprising: a server host having a single server AP; and a single client host having a plurality of client APs connected to the server host via a network device. First client AP identifier storage means for storing a client AP identifier for identification, and the client AP identifier stored in the client AP identifier storage means when the client AP establishes communication with the server host. A client AP identifier transmitting means for transmitting to the host, wherein the server host stores the client AP identifier when receiving the client AP identifier transmitted by the client AP identifier transmitting means. When the client AP identifier transmitted by the client AP identifier transmitting means is received, the client AP identifier is compared with the client AP identifier stored in the second client AP identifier storing means. Collating means; and recognizing that a fault has occurred when the client AP identifier transmitted by the AP identifier transmitting means by the collating means matches the client AP identifier stored in the second client AP identifier storing means. A communication partner failure detection system, comprising: a failure detection unit. 2. A communication system comprising a server host having a single server AP and a plurality of client hosts connected to the server host via a network device and having a plurality of client APs, wherein the plurality of client APs are identified. Client AP identifier storage means for storing a client AP identifier of the client AP, and session identification information comprising a client AP identifier of the client AP and an IP address when the client AP establishes communication with the server host. A session identification information transmitting unit that transmits to the server host, the server host stores the session identification information transmitted by the session identification information transmitting unit when receiving the session identification information storage unit, When the session identification information transmitted by the session identification information transmission means is received, the client AP identifier and IP address of the session identification information and the client AP identifier and IP address of the session identification information stored in the session identification information storage means And a client A of the session identification information transmitted by the session identification information transmitting means by the collation means.
A communication unit comprising: a failure detecting unit that recognizes that a failure has occurred when the P identifier and the IP address match the client AP identifier and the IP address of the session identification information stored in the session identification information storage unit. Partner failure detection system. 3. A communication system having a server host having a plurality of server APs and a plurality of client hosts connected to the server host via a network device and having a plurality of client APs, wherein the plurality of client APs are identified. Client AP identifier storage means for storing a client AP identifier of the client AP for storing session identification information comprising a client AP identifier of the client AP and an IP address when the client AP establishes communication with the server host. A session identification information transmitting unit that transmits the session identification information to the server host, wherein the server host communicates with the session identification information when the session identification information transmitted by the session identification information transmission unit is received. A session identification information storage unit for storing a PORT number of the AP, and a client AP identifier, an IP address, and a communication partner of the session identification information when the session identification information transmitted by the session identification information transmission unit is received. Collating means for collating the PORT number of the server AP with the client AP identifier of the session identification information stored in the session identification information storage means, the IP address, and the PORT number of the server AP with which the communication was made; Client A of the session identification information transmitted by the session identification information transmitting means
The P identifier, the IP address, and the PORT number of the server AP as the communication partner are stored in the session identification information storage means.
A communication partner failure detection system comprising: a failure detection unit that recognizes that a failure has occurred when the P identifier matches the IP address and the PORT number of the server AP that is the communication partner. 4. A communication method comprising: a server host having a single server AP; and a single client host having a plurality of client APs connected to the server host by a network device, wherein the plurality of client APs are identified. A first client AP identifier storage unit for storing a client AP identifier for the first client AP identifier storage unit, and a client AP identifier of the client AP when the client AP establishes communication with the server host. Transmitting a client AP identifier to be transmitted to the host; and a second client AP identifier stored in a second client AP identifier storage unit when the client AP identifier transmitted in the client AP identifier transmitting step is received. Storing the client AP identifier when the client AP identifier transmitted in the client AP identifier transmitting step is received and the client AP stored in the second client AP identifier storing step
A collation step of collating with an identifier; and a failure when the client AP identifier transmitted by the client AP identifier transmission step by the collation step matches the client AP identifier stored by the second client AP identifier storage step. A failure detection step of recognizing that a communication error has occurred. 5. A communication method having a server host having a single server AP and a plurality of client hosts connected to the server host via a network device and having a plurality of client APs, wherein the plurality of client APs are identified. Storing a client AP identifier of the client AP in a client AP identifier storage unit for performing a client AP identifier and an IP address of the client AP when the client AP establishes communication with the server host. A session identification information transmitting step of transmitting session identification information to the server host, the session identification information storage unit storing when the session identification information transmitted in the session identification information transmission step is received. Storing the session identification information transmitted by the session identification information transmitting step, and storing the client AP identifier and the IP address of the session identification information and the session stored by the session identification information storing step when receiving the session identification information. A collating step of collating the client AP identifier and the IP address of the identification information; and the client AP identifier and the IP address of the session identification information transmitted by the session identification information transmitting step by the collating step are stored in the session identification information storing step. A failure detecting step of recognizing that a failure has occurred when the stored session identification information matches the client AP identifier and the IP address. Hand failure detection method. 6. A communication method having a server host having a plurality of server APs and a plurality of client hosts connected to the server host via a network device and having a plurality of client APs, wherein the plurality of client APs are identified. A client AP identifier storing unit for storing a client AP identifier of the client AP for storing a client AP identifier, and a client AP identifier and an IP address of the client AP when the client AP establishes communication with the server host. A session identification information transmitting step of transmitting the session identification information to the server host, and receiving the session identification information transmitted by the session identification information transmitting step, and communicating with the session identification information. A session identification information storage step of storing the PORT number of the server AP that has become the server identification information, and a client AP of the session identification information when the session identification information transmitted in the session identification information transmission step is received. The identifier, the IP address, the PORT number of the server AP as the communication partner, the client AP identifier of the session identification information stored in the session identification information storage step, the IP address, and the PORT number of the server AP as the communication partner. A collating step for collating; a client AP identifier and an IP address of the session identification information transmitted by the session identification information transmitting step in the collating step; and a PORT number of a server AP as a communication partner. A failure detection step of recognizing that a failure has occurred when the client identification information stored in the session identification information storage step matches the client AP identifier and the IP address of the session identification information and the PORT number of the server AP with which the communication has been made. Characteristic communication partner failure detection method.