摘要:
The main storage, the communication interface portion and the circuit control module hold transmission data in the buffers until completion of the transmission has been confirmed. When a fault has occurred in the current operating system of the duplexed portions in the configuration elements of the host computer and the multi-circuit control unit, the duplexed portions are changed over from the current operating system to the stand-by system. In this case, information for reproducing data that has been lost due to the change-over is transmitted from the main storage and the circuit control module to the communication interface portion which has become the new current operating system. The communication interface portion which has become the new current operating system restarts the processing based on this information. Data integrity is guaranteed for the data of both directions of transmission and receiving between the host computer and the terminal without mutually confirming the state of data communications before the occurrence of the fault between the terminal and the host computer after the occurrence of the fault. Information exchanges of layer 3 or above are not carried out between the host computer and the terminal. Therefore, overhead of data communications can be minimized.
摘要:
A trouble processing method of ISDN communication system using an ISDN (Integrated Services Digital Network) and a control apparatus of ISDN communication system. Among a plurality of ISDN communication adapters included in an ISDN communication control apparatus, the same TEI (Terminal Endpoint Identifier) value as that of an active ISDN communication adapter is assigned to its stand-by ISDN communication adapter. The stand-by ISDN communication adapter is made to operate in the same manner as the active ISDN communication adapter with the exception of interruption of transmission of an LAPD (Link Access Producer on the D-channel) to an ISDN. The stand-by ISDN communication adapter is held in the same communication state as the active communication adapter. When a trouble has occurred in the active ISDN communication adapter, the interruption of transmission of the LAPD frame is cancelled and the stand-by ISDN communication adapter is activated as the active ISDN communication adapter. As a result, data communication using an ISDN can be conducted, and recovery processing at the time of occurrence of a trouble in an ISDN communication adapter can be rapidly executed without making the other party of communication conscious of it.
摘要:
A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The invention further includes a storage for storing correspondence between the first data processing unit and the first connecting point based on the identification information. Apparatus, responsive to reception of a second packet from a second data processing unit to be transmitted to the first data processing unit, transmits the second packet to the first data processing unit via the first connecting point based on the correspondence stored in the storage.
摘要:
A server system constructed by a network using a known PBX in such a manner that information processing terminal equipment and server devices are held in normally-used extensions of the PBX together with other terminals such as telephones, facsimiles, etc. Logical channel numbers of packet links between the PBX and the information processing terminal equipment are assigned to electrically-connected server devices in association with each other and sent to users. The users sends server use data to corresponding destinations by data packets to which the logical channel numbers are applied. The PBX performs a packet exchange process such that the logical channel numbers are respectively associated with physical addresses of the server devices. If the PBX regards the users as improper users, then it does not inform the users of the logical channel numbers. When a logical channel number of a server device used at a user desire is recognized, the user can utilize the PBX server system even if a proper user does not know a physical address of the server device.
摘要:
A server system constructed by a network using a known PBX in such a manner that information processing terminal equipment and server devices are held in normally-used extensions of the PBX together with other terminals such as telephones, facsimiles, etc. Logical channel numbers of packet links between the PBX and the information processing terminal equipment are assigned to electrically-connected server devices in association with each other and sent to users. The users sends server use data to corresponding destinations by data packets to which the logical channel numbers are applied. The PBX performs a packet exchange process such that the logical channel numbers are respectively associated with physical addresses of the server devices. If the PBX regards the users as improper users, then it does not inform the users of the logical channel numbers. When a logical channel number of a server device used at a user desire is recognized, the user can utilize the PBX server system even if a proper user does not know a physical address of the server device.
摘要:
A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The invention further includes a storage for storing correspondence between the first data processing unit and the first connecting point based on the identification information. Apparatus, responsive to reception of a second packet from a second data processing unit to be transmitted to the first data processing unit, transmits the second packet to the first data processing unit via the first connecting point based on the correspondence stored in the storage.
摘要:
A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The invention further includes a storage for storing correspondence between the first data processing unit and the first connecting point based on the identification information. Apparatus, responsive to reception of a second packet from a second data processing unit to be transmitted to the first data processing unit, transmits the second packet to the first data processing unit via the first connecting point based on the correspondence stored in the storage.
摘要:
A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The invention further includes a storage for storing correspondence between the first data processing unit and the first connecting point based on the identification information. Apparatus, responsive to reception of a second packet from a second data processing unit to be transmitted to the first data processing unit, transmits the second packet to the first data processing unit via the first connecting point based on the correspondence stored in the storage.
摘要:
In an ISDN network, data communications can be performed in two communication modes corresponding to line and packet switchings in the same network. The line switching is effective in transmitting mass data to a receiving station and receiving the same therefrom at high speed, and accounting is made to a period of time required for communication in a public network. On the other hand, the packet switching is effective in transmitting low-speed data or small amounts of data produced in a discrete manner, and accounting is made to the amount of transmitted data in the public network.With a valve toward making efficient use of the two communication modes, the present invention relates to a data communication apparatus of the type wherein the two communication modes are changed as needed so as to perform data communications, and to a data communication system suitable for use with the data communication apparatus. In other words, a means for performing data communication continuously over two calls is provided so as to change one communication mode to another under data communication based on a user's request.Thus, when the amount of creation of data varies appreciably under communication, data communication is made based on the optimal communication mode determined according to the amount of creation of the data.