Communication network having adjustable response timeouts and method therefore

• US 7,240,087 B1
• Filed: 06/27/1997
• Issued: 07/03/2007
• Est. Priority Date: 06/27/1997
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Walker, Anthony Dean
• Primary Examiner(s): VU, THONG H
• Application Number:
  US08/883,710
• Time in Patent Office: 3,658 Days
• Field of Search: 395/185.08, 370/85.8, 370/280, 370/668, 370/509, 370/252, 379/98, 709/224, 709/200, 371/33, 341/51, 714/749
• US Class Current: 709/200
• CPC Class Codes: H04L 1/188 Time-out mechanisms

Abstract

A communication network implements a timing system that closely approximates network response times so that information may be transmitted between two data processing systems within the network in a timely and efficient manner. During operation of the communication network, a sending data processing system sends query data to a receiving data processing system. A response timer within the sending data processing system is initialized to track the query operation. If the receiving data processing system provides a response to the sending data processing system before the response timer expires, the timing implemented for data communications is proper for the communication network. However, if the receiving data processing system fails to provide a response within a time specified by the response timer, the transmitting data processing system resends a query frame. Subsequently, the sending data processing system in the communication network gradually increases a response time until the time measured by the response timer does not expire before a response is received by the sending data processing system.

Claims

1. A method for operating a communication system, comprising the steps of:

transmitting a first information frame;

selectively receiving a first response in response to transmission of the first information frame;

measuring a first amount of time between transmission of the first information frame and receipt of the first response;

selectively modifying a response time value in response to the first amount of time, wherein said step of measuring a first amount of time between transmission of the first information frame and receipt of the first response uses a timer operating in response to a clock, and wherein said response time value is a response time value of said timer; and

incrementing an initial response time value by a timer resolution value, to form the response time value.

2. The method of claim 1 wherein the initial response time value is incremented up to a maximum response time value.

3. The method of claim 1 wherein the initial response time value is a default value.

4. A method for operating a communication system, comprising the steps of:

transmitting a first frame of information;

initiating operation of a timer with a first response time;

determining when a first query response has been received; and

selectively incrementing the first response time when the first query response has been received;

wherein the first response time is incremented by a timer resolution value.

5. A method for operating a communication system, comprising the steps of:

transmitting a first frame of information;

initiating operation of a timer with a first response time;

determining when a first query response has been received;

selectively incrementing the first response time when the first query response has been received;

setting a transmit sequence value when the first frame of information is transmitted;

initiating operation of a response timer when the first information frame is transmitted;

comparing the transmit sequence value and a receive sequence value when the first response is received; and

idling operation of the response timer when the transmit sequence value corresponds to the receive sequence value.

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

restarting operation of the response timer when the transmit sequence value differs from the receive sequence value.

7. A method for operating a communication system comprising the steps of:

transmitting a first frame of information;

initiating operation of a timer with a first response time;

determining when a first query response has been received;

selectively incrementing the first response time when the first query response has been received;

transmitting a second information frame;

selectively receiving a second response in response to transmission of the second information frame;

measuring a second amount of time between transmission of the second information frame and receipt of the second response;

selectively initializing a query timer with a maximum response time value; and

selectively modifying the response time value to correspond to a residual time value remaining in a response timer after the second amount of time has passed.

8. The method of claim 7 wherein the response time value is selectively modified to equal the residual time value plus a timer resolution value.

9. A first data processing system for communicating with a second data processing system, comprising:

interface means for transmitting a first information frame and for selectively receiving a first response in response to transmission of the first information frame;

a timer for measuring a first amount of time between transmission of the first information frame and receipt of the first response, the timer being coupled to the interface means;

a central processing unit coupled to the timer for selectively modifying a response time value in response to the first amount of time; and

means for incrementing the response timer value by a preselected time period in response to the first amount of time.