Display-model mapping for TN3270 client

• US 6,128,662 A
• Filed: 08/29/1997
• Issued: 10/03/2000
• Est. Priority Date: 08/29/1997
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Boe, Michael, Bolton, Derek W.
• Primary Examiner(s): Dinh, Dung C.
• Assistant Examiner(s): LE, QUOC KHANH
• Application Number:
  US08/920,470
• Time in Patent Office: 1,131 Days
• Field of Search: 709/228, 709/218, 709/227, 709/249, 709/219, 709/203, 709/222, 709/250
• US Class Current: 709/228
• CPC Class Codes: H04L 67/08 specially adapted for terminal emulation, e.g. Telnet
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

To determine the name that specifies the Systems Network Architecture logical-unit-characteristics set that a host (12) systems services control point is to associate with a TN3270 server (18) logical-unit process that is to represent a client terminal (14), the server (18) generates the name from the client'"'"'s device type algorithmically, i.e., without looking the name up in a server-maintained table entered by using the device type as the key. This eliminates the need for server updates when new device types are introduced. Additionally, the algorithm used to generate the name depends on whether the client has negotiated to receive a copy of the data transmitted in the BIND message by which another logical unit initiates a session with the logical unit that will represent the client. In that way, the host'"'"'s systems services control point can send the client data streams in the form that it expects, and the server is relieved of the need to perform any translation.

Claims

1. For transferring information between a TN3270 client on a Telnet connection and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a communications gateway including circuitry for:

A) performing a TN3270 negotiation with the TN3270 client by way of a Telnet connection and thereby obtaining a device-type designation therefrom;

B) algorithmically generating a computed model string as a function of the device-type designation;

C) associating a given logical-unit process with the TN3270 client;

D) by way of the SNA connection, using the computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) transferring information between the host and the TN3270 client by;

i) employing the Telnet connection to communicate with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

2. A communications gateway as defined in claim 1 wherein the circuitry for generating the computed model string generates the computed model string additionally as a function of whether the TN3270 client has negotiated a BIND-IMAGE option.

3. A communications gateway as defined in claim 2 wherein the computed model string comprises an ordered sequence of characters, the character in a predetermined position in the sequence assumes a first value when the TN3270 client has negotiated the BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the TN3270 client has not negotiated the BIND-IMAGE option.

4. A communications gateway as defined in claim 1 further including circuitry for, after transferring information between the host and the first-mentioned TN3270 client:

A) performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection and thereby obtaining therefrom a second device-type designation different from the first device-type designation;

B) algorithmically generating a different, second computed model string as a function of the second device-type designation;

C) associating the given logical-unit process with the second TN3270 client;

D) by way of the SNA connection, using the second computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communicate with the second TN3270 client; and

ii) employing the given logical-unit process to communicate with the host by way of the SNA connection.

5. A communications gateway as defined in claim 4 wherein the gateway uses the second computed model string to identify the parameter set to the host without having deactivated the given logical unit since the first-mentioned model string was used to identify the parameter set to the host.

6. A communications gateway as defined in claim 5 wherein the gateway identifies the parameter sets to the host by transmitting the computed model strings in SNA Network Management Vector Transport messages.

7. A communications gateway as defined in claim 4 wherein the circuitry for generating the computed model strings generates each computed model string additionally as a function of whether the respective TN3270 client has negotiated a BIND-IMAGE option.

8. A communications gateway as defined in claim 7 wherein the computed model strings comprise respective ordered sequences of characters, the character in a predetermined position in each said sequence assumes a first value when the respective TN3270 client has negotiated a BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the respective TN3270 client has not negotiated the BIND-IMAGE option.

9. A communications gateway as defined in claim 1 wherein the gateway identifies the parameter set to the host by transmitting the model string in an SNA Network Management Vector Transport message.

10. A communications gateway as defined in claim 9 wherein the SNA Network Management Vector Transport message contains the model string in an SNA Product Set ID vector.

11. For transferring information between a TN3270 client on a Telnet connection and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a method comprising the steps of:

A) performing a TN3270 negotiation with the TN3270 client by way of a Telnet connection and thereby obtaining a device-type designation therefrom;

B) algorithmically generating a computed model string as a function of the device-type designation;

C) associating a given logical-unit process with the TN3270 client;

D) by way of the SNA connection, using the computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) transferring information between the host and the TN3270 client by;

i) employing the Telnet connection to communicate with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

12. A method as defined in claim 11 wherein the step of generating the computed model string comprises generating the computed model string additionally as a function of whether the TN3270 client has negotiated a BIND-IMAGE option.

13. A method as defined in claim 12 wherein the computed model string comprises an ordered sequence of characters, the character in a predetermined position in the sequence assumes a first value when the TN3270 client has negotiated the BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the TN3270 client has not negotiated the BIND-IMAGE option.

14. A method as defined in claim 11 further comprising the steps of, after transferring information between the host and the first-mentioned TN3270 client:

A) performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection and thereby obtaining therefrom a second device-type designation different from the first device-type designation;

B) algorithmically generating a different, second computed model string as a function of the second device-type designation;

C) associating the given logical-unit process with the second TN3270 client;

D) by way of the SNA connection, using the second computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communicate with the second TN3270 client; and

ii) employing the given logical-unit process to communicate with the host by way of the SNA connection.

15. A method as defined in claim 14 wherein the step of using the second computed model string to identify the parameter set to the host is performed without having deactivated the given logical unit since the first-mentioned model string was used to identify the parameter set to the host.

16. A method as defined in claim 15 wherein the steps of identifying the parameter sets to the host comprise transmitting the computed model strings in SNA Network Management Vector Transport messages.

17. A method as defined in claim 14 wherein the steps of generating the computed model strings comprise generating the respective computed model strings additionally as a function of whether the respective TN3270 clients have negotiated BIND-IMAGE options.

18. A method as defined in claim 17 wherein the computed model strings comprise respective ordered sequences of characters, the character in a predetermined position in each said sequence assumes a first value when the respective TN3270 client has negotiated a BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the respective TN3270 client has not negotiated the BIND-IMAGE option.

19. A method as defined in claim 11 wherein the step of identifying the parameter set to the host comprises transmitting the computed model string in an SNA Network Management Vector Transport message.

20. A method as defined in claim 19 wherein the SNA Network Management Vector Transport message contains the model string in an SNA Product Set ID vector.

21. For transferring information between TN3270 clients on Telnet connections and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a communications gateway including circuitry for:

A) performing a TN3270 negotiation with a first TN3270 client by way of a Telnet connection;

B) associating a given logical-unit process with the TN3270 client;

C) by way of the SNA connection, using a first model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate;

D) transferring information between the host and the first TN3270 client by;

i) employing the Telnet connection to communicate with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection;

E) performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection;

F) associating the given logical-unit process with the second TN3270 client;

G) without having deactivated the given logical unit since the first model string was used to identify the parameter set in accordance with which the given logical unit was to communicate, using a different, second model string to identify to the host by way of the SNA connection the parameter set in accordance with which the given logical unit is to communicate;

H) transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communicate with the second TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

22. A communications gateway as defined in claim 21 the gateway identifies the parameter sets to the host by transmitting the computed model strings in SNA Network Management Vector Transport messages.

23. A communications gateway as defined in claim 22 wherein the SNA Network Management Vector Transport messages contain the model strings in SNA Product Set ID vectors.

24. For transferring information between TN3270 clients on Telnet connections and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a method comprising the steps of:

A) performing a TN3270 negotiation with a first TN3270 client by way of a Telnet connection;

B) associating a given logical-unit process with the TN3270 client;

C) by way of the SNA connection, using a first model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate;

D) transferring information between the host and the first TN3270 client by;

i) employing the Telnet connection to communicate with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection;

E) performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection;

F) associating the given logical-unit process with the second TN3270 client;

G) without having deactivated the given logical unit since the first model string was used to identify the parameter set in accordance with which the given logical unit was to communicate, using a different, second model string to identify to the host by way of the SNA connection the parameter set in accordance with which the given logical unit is to communicate;

H) transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communicate with the second TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

25. A method as defined in claim 24 wherein the steps of using model strings to identify to the host the parameter set in accordance with which the given logical unit is to communicate comprises transmitting the model string in an SNA Network Management Vector Transport message.

26. A method as defined in claim 25 wherein the SNA Network Management Vector Transport message contains the model string in a Product Set ID vector.

27. For transferring information between a TN3270 client on a Telnet connection and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a communications gateway comprising:

A) means for performing a TN3270 negotiation with the TN3270 client by way of a Telnet connection and thereby obtaining a device-type designation therefrom;

B) means for algorithmically generating a computed model string as a function of the device-type designation;

C) means for associating a given logical-unit process with the TN3270 client;

D) by way of the SNA connection, using the computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) means for transferring information between the host and the TN3270 client by;

i) employing the Telnet connection to communication with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

28. A communications gateway as defined in claim 27 wherein the means for generating the computed model string comprises means for generating the computed model string additionally as a function of whether the TN3270 client has negotiated a BIND-IMAGE option.

29. A communications gateway as defined in claim 28 wherein the computed model string comprises an ordered sequence of characters, the character in a predetermined position in the sequence assumes a first value when the TN3270 client has negotiated the BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the TN3270 client has not negotiated the BIND-IMAGE option.

30. A communication gateway as defined in claim 27 further comprising means for, after transferring information between the host and the first-mentioned TN3270 client:

A) performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection and thereby obtaining therefrom a second device-type designation different from the first device-type designation;

B) algorithmically generating a different, second computed model string as a function of the second device-type designation;

C) associating the given logical-unit process with the second TN3270 client;

D) by way of the SNA connection, using the second computed model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate; and

E) transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communication with the second TN3270 client; and

ii) employing the given logical-unit process to communicate with the host by way of the SNA connection.

31. A communications gateway as defined in claim 30 wherein the means for using the second computed model string to identify the parameter set to the host does so without having deactivated the given logical unit since the first-mentioned model string was used to identify the parameter set to the host.

32. A communications gateway as defined in claim 31 wherein the means for identifying the parameter sets to the host comprise means for transmitting the computed model strings in SNA Network Management Vector Transport messages.

33. A communications gateway as defined in claim 30 wherein the means for generating the computed model strings comprise means for generating the respective computed model strings additionally as a function of whether the respective TN3270 clients have negotiated BIND-IMAGE options.

34. A communications gateway as defined in claim 33 wherein the computed model strings comprise respective ordered sequences of characters, the character in a predetermined position in each said sequence assumes a first value when the respective TN3270 client has negotiated a BIND-IMAGE option, and the character in the predetermined position assumes a different, second value when the respective TN3270 client has not negotiated the BIND-IMAGE option.

35. A communications gateway as defined in claim 27 wherein the means for identifying the parameter set to the host comprises means for transmitting the computed model string in an SNA Network Management Vector Transport message.

36. A communications gateway as defined in claim 35 wherein the SNA Network Management Vector Transport message contains the model string in an SNA Product Set ID vector.

37. For transferring information between TN3270 clients on Telnet connections and a host on an SNA connection, the host maintaining a parameter table of local-unit parameter sets identified by respective model strings, a communications gateway:

A) means for performing a TN3270 negotiation with a first TN3270 client by way of a Telnet connection;

B) means for associating a given logical-unit process with the TN3270 client;

C) means for, by way of the SNA connection, using a first model string to identify to the host the parameter set in accordance with which the given logical unit is to communicate;

D) means for transferring information between the host and the first TN3270 client by;

i) employing the Telnet connection to communicate with the TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection;

E) means for performing a TN3270 negotiation with a second TN3270 client by way of a Telnet connection;

F) means for associating the given logical-unit process with the second TN3270 client;

G) means for, without having deactivated the given logical unit since the first model string was used to identify the parameter set in accordance with which the given logical unit was to communicate, using a different, second model string to identify to the host by way of the SNA connection the parameter set in accordance with which the given logical unit is to communicate;

H) means for transferring information between the host and the second TN3270 client by;

i) employing the Telnet connection to communicate with the second TN3270 client; and

ii) employing the logical-unit process to communicate with the host by way of the SNA connection.

38. A communications gateway as defined in claim 37 wherein the means for using model strings to identify to the host the parameter set in accordance with which the given logical unit is to communicate comprises means for transmitting the model string in an SNA Network Management Vector Transport message.

39. A communications gateway as defined in claim 38 wherein the SNA Network Management Vector Transport message contains the model string in a Product Set ID vector.