System and method for managing packet-switched connections

• US 6,018,770 A
• Filed: 10/13/1997
• Issued: 01/25/2000
• Est. Priority Date: 10/13/1997
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Blackberry Limited
• Inventors: MacCallum, Louise A., Mousseau, Gary P., Little, Herb A., Church, Mark E.
• Primary Examiner(s): Asta, Frank J.
• Assistant Examiner(s): VU, THONG H
• Application Number:
  US08/949,297
• Time in Patent Office: 834 Days
• Field of Search: 455/557, 455/13.2, 455/12.1, 395/500, 395/200, 395/182.02, 395/650, 709/141, 709/120, 709/200, 709/240, 709/238, 709/223, 709/224, 370/85.13, 370/389, 370/455, 370/401, 379/242
• US Class Current: 709/223
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 63/0281 Proxies
• CPC Class Codes: H04L 63/0876 based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint
• CPC Class Codes: H04L 67/025 for remote control or remote monitoring of applications
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal

Abstract

A system and method for managing connections between one or more local terminals and one or more remote systems over a packet-switched network is disclosed. The invention includes a gateway computer that forms a bridge between the local terminals and the one or more host systems, the gateway and the local terminals including computer software instructions for embedding and filtering special connection identification information in each transaction request. The local terminals embed connection identification information into each request packet requesting a connection to a remote host system, and the gateway filters this information and verifies that the gateway and local terminal(s) are synchronized. The gateway then manages the communication to the host system using the native protocol of the host, thereby minimizing communication over the packet-switched network. By synchronizing the connection attempts of the local terminals to the gateway, problems associated with connecting multiple transaction-generating terminals to one or more host systems via a packet-switched network are minimized.

Claims

1. A method of managing connections between a plurality of point-of-sale terminals and a host system via a packet-switched network, the method comprising the steps of:

providing a gateway computer that forms a bridge between the point-of-sale terminals and the host system;

embedding connection identification information into a terminal request packet generated by the point-of-sale terminals when a connection is to be established to the host system, the connection identification information including a terminal connection identification variable;

transmitting the terminal request packet to the gateway;

verifying that the gateway and the point-of-sale terminal transmitting the terminal request packet are synchronized by comparing the terminal connection identification variable to a gateway connection identification variable stored at the gateway, wherein the gateway connection identification variable is associated with the particular point-of-sale terminal transmitting the terminal request packet; and

if the gateway and point-of-sale terminal are synchronized, then creating a connection between the gateway and the host system.

2. The method of claim 1, wherein the embedding step includes the steps of:

setting the terminal connection identification variable to a predetermined starting value when the point-of-sale terminal is reset or power is applied to the terminal;

waiting for a transaction to occur at the point-of-sale terminal; and

building a terminal request packet at the point-of-sale terminal that includes the terminal connection identification variable.

3. The method of claim 2, wherein the embedding step includes the additional step of:

prior to building the request packet, determining whether a prior transaction completed normally, and if so, building the request packet with an ACK character.

4. The method of claim 2, wherein the verifying step includes the steps of:

storing a plurality of gateway connection identification variables at the gateway that correspond to each point-of-sale terminal;

setting the gateway connection identification variables to a predetermined starting value when the gateway is reset or power is applied to the terminal;

waiting for a terminal request packet from a point-of-sale terminal;

extracting the terminal connection identification variable from the terminal request packet; and

comparing the extracted terminal connection identification variable to the gateway connection identification variable that corresponds to the particular point-of-sale terminal to determine whether the gateway and the point-of-sale terminal are synchronized.

5. The method of claim 4, wherein the creating a connection step includes the steps of:

setting the gateway connection identification variable equal to the terminal connection identification variable;

extracting host addressing information from the terminal request packet;

looking up the actual host address using the extracted host addressing information; and

opening a connection between the gateway and the host using the actual host address.

6. The method of claim 5, further comprising the step of:

transmitting information from the terminal request packet to the host system.

7. The method of claim 6, further comprising the steps of:

receiving the information from the terminal request packet at the host system; and

transmitting a host response to the gateway in response to the information from the terminal request packet.

8. The method of claim 7, further comprising the steps of:

receiving the host response at the gateway; and

building a host response packet at the gateway that includes the host response and the gateway connection identification variable corresponding to the particular point-of-sale terminal.

9. The method of claim 8, further comprising the steps of:

transmitting the host response packet from the gateway to the point-of-sale terminal;

receiving the host response packet at the point-of-sale terminal;

extracting the gateway connection identification variable from the host response packet; and

comparing the extracted gateway connection identification variable to the terminal connection identification variable associated with the point-of-sale terminal.

10. The method of claim 9, further comprising the steps of:

if the extracted gateway connection identification variable is equal to the terminal connection identification variable then;

building an acknowledge packet at the point-of-sale terminal including an ACK character and the terminal connection identification variable; and

transmitting the acknowledge packet from the point-of-sale terminal to the gateway.

11. The method of claim 10, further comprising the steps of:

verifying that the gateway and the point-of-sale terminal transmitting the acknowledge packet are still synchronized; and

if the gateway and the point-of-sale terminal are synchronized, then transmitting the acknowledge packet to the host system.

12. The method of claim 10, further comprising the steps of:

incrementing the terminal connection identification variable; and

waiting for the next transaction to occur at the point-of-sale terminal.

13. The method of claim 2, further comprising the steps of:

the point-of-sale terminal waiting for a response packet from the gateway;

if a predetermined period of time has lapsed and no response packet has been received by the point-of-sale terminal, then;

aborting the current transaction;

incrementing the terminal connection identification variable; and

waiting for the next transaction to occur at the point-of-sale terminal.

14. The method of claim 7, further comprising the steps of:

receiving the host response at the gateway;

determining whether the host response contains an end-of-transmission (EOT) character;

if the host response contains the EOT character, then;

closing the connection to the host system;

incrementing the gateway connection identification variable; and

waiting for the next terminal request packet.

15. The method of claim 1, wherein the packet-switched network is a wireless network.

16. A system for managing connections between one or more local terminals and a remote host system, comprising:

a gateway computer system connected between the local terminals and the remote host system;

connection protocol software stored at the local terminals for embedding a terminal connection identification variable into request packets generated by the local terminals when the terminal is requesting a connection to a remote host system, wherein the local terminals alter the terminal connection identification variable for each connection request;

connection protocol software stored at the gateway computer for extracting the embedded terminal connection identification variable and determining if the gateway and the requesting local terminal are synchronized by comparing the value of the terminal connection identification variable to a stored gateway connection identification variable for the particular local terminal making the connection request.

17. The system of claim 16, wherein the gateway includes a connection identification variable look-up table that stores the gateway connection identification variables for each local terminal.

18. The system of claim 16, wherein the gateway includes a configuration table that stores the network addresses of the one or more host systems connected to the gateway.

19. The system of claim 17, wherein the connection protocol software stored at the local terminals comprises:

means for setting the terminal connection identification variable to a predetermined value when the local terminal is reset or power is applied to the terminal;

means for receiving transaction data at the local terminal; and

means for building a terminal request packet at the local terminal that includes the terminal connection identification variable and the transaction data.

20. The system of claim 19, wherein the connection protocol software stored at the local terminals further comprises:

means for determining whether a prior transaction completed normally, and if so, for building the request packet with an ACK character.

21. The system of claim 17, wherein the connection protocol software stored at the gateway comprises:

means for setting the gateway connection identification variables to a predetermined value when the gateway is reset or power is applied to the gateway;

means for receiving a terminal request packet from a local terminal;

means for extracting the terminal connection identification variable from the received terminal request packet; and

means for determining whether the gateway and the local terminal are synchronized.

22. The system of claim 21, further comprising:

means for creating a connection between the local terminal and a remote host system if the gateway and the local terminal are synchronized.

23. The system of claim 22, wherein the means for creating a connection comprises:

means for setting the gateway connection identification variable to the extracted terminal connection identification variable;

means for extracting host addressing information from the terminal request packet; and

means for opening a connection between the gateway and the host system using the extracted addressing information.