Message relaying system for a distributed processing system

• US 5,361,388 A
• Filed: 04/07/1992
• Issued: 11/01/1994
• Est. Priority Date: 04/09/1991
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kutsuna, Toshimasa
• Primary Examiner(s): Shaw, Dale M.
• Assistant Examiner(s): Barry, Lance Leonard
• Application Number:
  US07/864,785
• Time in Patent Office: 938 Days
• Field of Search: 370/60, 370/94.1, 370/110.1, 395/200, 395/275, 395/325, 364/200 MS File, 364/900 MS File
• US Class Current: 710/9
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00

Abstract

A terminal identifier correspondence management table provides the management of logical terminal identifiers generated by a host computer and assigned to each logical terminal and corresponding terminal identifiers generated for each terminal by a distributed computer. A logical terminal identifier is assigned to each logical terminal and is used by an interactive processing unit operating on a host computer. A distributed computer assigns a terminal identifier to each terminal and adds a terminal identifier into each message received by the distributed computer from a terminal, and the host computer deletes the terminal identifier in each message received from the distributed computer. The host computer provides the pertinent message to the interactive processing unit as if it were received from the logical terminal indicated by the logical terminal identifier corresponding to the received terminal identifier. The host computer, in response to a transmission request from an interactive processing unit, adds the terminal identifier of the terminal corresponding to the logical terminal identifier into the message, as determined from the terminal identifier correspondence management table. The distributed computer determines the terminal on the basis of the terminal identifier in the message received from the host computer and deletes the terminal identifier from the message.

Claims

1. An apparatus for relaying messages in a distributed processing system containing a plurality of terminals, a distributed computer connected to said terminals by a first set of communication lines, a plurality of host computers connected to said distributed computer by a second set of communication lines, wherein said terminals relay messages to and from said distributed computer to perform interactive processing with said host computers, said apparatus comprising:

an interactive processing unit operating in each of said host computers;

a terminal identifier correspondence management table in each of said host computers, for managing logical terminal identifiers and corresponding terminal identifiers, said logical terminal identifiers for use by said interactive processing unit;

a communication control table in said distributed computer containing terminal identifiers corresponding to each of said terminals;

first terminal identifier adding means in said distributed computer, connected to said communication control table and communicatively connected to each of said terminals, for adding said terminal identifier corresponding to said terminal found in said communication control table into a message received by said distributed computer from one of said terminals, and sending said message to one of said host computers, said first terminal identifier adding means extracting a logical terminal identifier contained in said message and determining said terminal identifier by finding said terminal identifier corresponding to said logical terminal identifier from said communication control table;

first terminal identifier deleting means in each of said host computers, connected to said interactive processing unit and said terminal identifier correspondence management table and communicatively connected to said distributed computer, for deleting said terminal identifier from a message received by one of said host computers from said distributed computer, and providing said message to said interactive processing unit as if the message were received from the logical terminal indicated by the logical terminal identifier corresponding to the terminal identifier found in said terminal identifier correspondence management table;

second terminal identifier adding means in each of said host computers, connected to said interactive processing unit and said terminal identifier correspondence management table and used in transmit requests sent to said distributed computer, for determining the terminal identifier of a destination terminal for a message, from said terminal identifier correspondence management table, using said logical terminal identifier from said interactive processing unit, and adding said terminal identifier into said message; and

second terminal identifier deleting means in said distributed computer, connected to said communication control table and communicatively connected to each of said host computers and communicatively connected to each of said terminals, for finding, on the basis of a terminal identifier in a message received by said distributed computer from one of said host computers, said destination terminal from said communication control table and deleting said terminal identifier from said message and sending said message to said destination terminal.

2. An apparatus for relaying messages as claimed in claim 1 wherein a unique logical terminal identifier is provided for each logical terminal.

3. An apparatus for relaying messages as claimed in claim 1 wherein a unique terminal identifier is provided for each of said terminals.

4. An apparatus for relaying messages as claimed in claim 1 wherein said logical terminal identifiers and said terminal identifiers are provided by said host computers and said distributed computer respectively.

5. An apparatus for relaying messages as claimed in claim 1 wherein said communication control table is formulated by said distributed computer.

6. A method for relaying messages in a distributed processing system containing a plurality of terminals, a distributed computer connected to said terminals by a first set of communication lines, a plurality of host computers, each of said host computers containing an interactive processing unit, said host computers connected to said distributed computer by a second set of communication lines, wherein said terminals relay messages to and from said distributed computer to perform interactive processing with said host computers, comprising the steps of:

generating a communication control table in said distributed computer containing terminals identifiers corresponding to said terminals;

generating a correspondence management table in each of said host computers, containing logical terminal identifiers and corresponding said terminal identifiers, said logical terminal identifiers for use by said interactive processing unit;

adding said terminal identifier corresponding to one of said terminals, into each message received by said distributed computer from one of said terminals, as determined by said logical terminal identifier contained in said message and said correspondence management table used to equate said logical terminal identifier to said terminal identifier;

deleting said terminal identifier from each message received by one of said host computers from said distributed computer;

providing said message received by said one of said host computers to said interactive processing unit as if the message were received from the logical terminal indicated by the logical terminal identifier corresponding to the terminal identifier found in said terminal identifier correspondence management table;

determining the terminal identifier of a destination terminal for a message from said terminal identifier correspondence management table, said terminal identifier corresponding to said logical terminal identifier received from said interactive processing unit;

adding said terminal identifier corresponding to said logical terminal identifier received from said interactive processing unit into said message;

sending said message to the distributed computer;

determining, on the basis of said terminal identifier in a message received by said distributed computer from one of said host computers, a destination terminal from said communication control table; and

deleting said terminal identifier from said message and sending said message to said destination terminal.

7. A distributed processing system, including a plurality of terminals, comprising:

a distributed computer communicatively connected to a plurality of host computers, said distributed computer including;

a communication control table containing terminal identifiers corresponding to each of said terminals;

first terminal identifier adding means connected to said communication control table and communicatively connected to each of said terminals, for adding said terminal identifier corresponding to said terminal found in said communication control table into a message received by said distributed computer from one of said terminals, and sending said message to a host selecting means, said first terminal identifier adding means extracting a logical terminal identifier contained in said message and determining said terminal identifier by finding said terminal identifier corresponding to said logical terminal identifier from said communication control table;

said host selecting means connected to said first terminal identifier adding means and communicatively connected to each of said host computers, for selecting one of said host computers to process said message received from said first terminal identifier adding means,

second terminal identifier deleting means connected to said communication control table and communicatively connected to each of said plurality of said host computers and communicatively connected to each of said terminals for finding, on the basis of a terminal identifier in a message received by said distributed computer from one of said plurality of said host computers, said destination terminal from said communication control table and deleting said terminal identifier from said message and sending said message to said destination terminal,

and wherein

each of said host computers, communicatively connected to said distributed computer, includes;

an interactive processing unit;

a terminal identifier correspondence management table for managing logical terminal identifiers and corresponding terminal identifiers, said logical terminal identifiers for use by said interactive processing unit;

second terminal identifier adding means connected to said interactive processing unit and said terminal identifier correspondence management table and communicatively connected to said distributed computer, used in transmit requests sent to said distributed computer, for determining the terminal identifier of a destination terminal for a message, from said terminal identifier correspondence management table, using said logical terminal identifier from said interactive processing unit, and adding said terminal identifier into said message; and

first terminal identifier deleting means connected to said interactive processing unit and said terminal identifier correspondence management table and communicatively connected to said distributed computer, for deleting said terminal identifier from a message received by one of said plurality of host computers from said distributed computer, and providing said message to said interactive processing unit as if the message were received from the logical terminal indicated by the logical terminal identifier corresponding to the terminal identifier found in said terminal identifier correspondence management table.