System and method for improving network performance through inter frame spacing adaptation

• US 5,642,360 A
• Filed: 08/28/1995
• Issued: 06/24/1997
• Est. Priority Date: 08/28/1995
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Trainin, Solomon
• Primary Examiner(s): Kim, Kenneth S.
• Application Number:
  US08/520,143
• Time in Patent Office: 666 Days
• Field of Search: 370/79, 370/85.3, 370/93, 370/94.1, 370/17, 370/229, 370/230, 370/232, 370/252, 370/465, 395/200.06, 395/200.11, 395/200.13
• US Class Current: 370/230
• CPC Class Codes: H04L 12/40013 Details regarding a bus controller
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints

Abstract

An Inter Frame Spacing ("IFS") adaptation routine, operating in combination with a network controller, to alter the IFS parameter utilized by the network controller to regulate data throughput. Such alteration is performed in real-time according to the topology and load of its Ethernet network. Upon determining that current Back-to-Back frames of data propagating through the Ethernet network are sensitive to IFS adaptation, the IFS adaptation routine configures the IFS parameter of its network controller based on its transmit activity and collision intensity.

Claims

1. A method for altering Inter Frame Spacing to improve performance of a network, the method comprising the steps of:

ascertaining a transmit activity of the network; and

checking whether said transmit activity is greater than or equal to a transmit activity threshold, wherein if said transmit activity is greater than or equal to said transmit activity threshold, then

(i) ascertaining a collision intensity experienced by the network, and

(ii) adjusting the Inter Frame Spacing until said collision intensity rises above a collision intensity threshold, and

if said transmit activity is less than said transmit activity threshold, then setting the Inter Frame Spacing to a minimum Inter Frame Spacing delay associated with the network.

2. The method according to claim 1, wherein prior to said adjusting step, further comprises a step of determining whether the network is responsive to an increase in the Inter Frame Spacing.

3. The method according to claim 2, wherein said determining step includes the steps of

setting the Inter Frame Spacing equal to a slot time of the network during a first access;

ascertaining said collision intensity during a second access subsequent to said first access; and

comparing said collision intensity during said second access with said collision intensity threshold to conclude the network is responsive if said collision intensity is greater than or equal to said collision intensity threshold.

4. The method according to claim 1, wherein said adjusting step includes the steps of

setting the Inter Frame Spacing equal to a preselected Inter Frame Spacing delay;

and

checking whether said collision intensity for the network having said preselected Inter Frame Spacing delay is greater than or equal to said collision intensity threshold, wherein

if said collision intensity threshold is greater than or equal to said collision intensity threshold, halting adjustment of the Inter Frame Spacing until said collision intensity falls below said collision intensity threshold, and

if said collision intensity is less than said collision intensity threshold,

increasing said preselected Inter Frame Spacing delay by a single Inter Frame Spacing delay increment, and

reporting said checking step.

5. The method according to claim 1, wherein said adjusting step is performed in real-time.

6. A network comprising:

a network medium;

a first station coupled to said network medium; and

a second station coupled to said network medium, said second station including

a network controller used to regulate data throughput from said second station onto said network medium, and

a memory element coupled to said network controller, said memory element including a network device driver configured to ascertain a transmit activity of the network, to ascertain a collision intensity experienced by the network when the transmit activity is equal to or exceeds a transmit activity threshold, and to modify an Inter Frame Spacing used by said network controller until the collision intensity threshold rises above a collision intensity threshold.

7. The network according to claim 6, wherein the memory element is main memory.

8. The network according to claim 6, wherein the memory element is local memory, implemented with said network controller within a network interface of said second station.

9. The network according to claim 6, wherein said network device driver includes an Inter Frame Spacing adaptation routine executed by the second station to modify the Inter Frame Spacing in real-time.

10. The network according to claim 6, wherein said network driver further (iv) sets the Inter Frame Spacing to a minimum Inter Frame Spacing delay when said transmit activity is less than a transmit activity threshold.

11. The network according to claim 6, wherein, prior to adjusting the Inter Frame Spacing used by the network controller, said network device driver determines whether the network is responsive to an increase in the Inter Frame Spacing.

12. The network according to claim 11, wherein said network device driver determines whether the network is responsive to the increase in the Inter Frame Spacing by (i) setting the Inter Frame Spacing equal to a slot time of the network during a first access, (ii) calculating said collision intensity during a second access subsequent to said first access, and (iii) comparing said collision intensity during said second access with, a collision intensity threshold to conclude the network is responsive if said collision intensity is greater than or equal to said collision intensity threshold.

13. A network comprising:

bus means for propagating data frames;

first communicative means for receiving said data frames through said bus means, said first communicative means being coupled to said bus means; and

second communicative means for transmitting said data frames, said second communicative means being coupled includes

controller means for regulating throughput of said data frames onto said bus means, and

memory means for storing an Inter Frame Spacing adaptation routine to configure an Inter Frame Spacing used by said controller means, the Inter Frame Spacing of the controller means being adjusted until a collision experienced by the network rises above a collision intensity threshold when the Inter Frame Spacing adaptation routine is executed and a transmit activity is greater than or equal to a transmit activity threshold.

14. The network according to claim 13, wherein the memory means is local memory implemented within said controller means within a network interface of said second communicative means thereby coupling said second communicative means to said bus means.

15. The network according to claim 13, wherein the memory means is main memory.

16. The network according to claim 13, wherein said controller means regulates throughput of said data frames in real-time.

17. A network comprising:

a network medium;

a first station coupled to said network medium; and

a second station coupled to said network medium, said second station including

a network controller used to regulate data throughput from said second station onto said network medium, and

a memory element coupled to said network controller, said memory element including a network device driver including an Inter Frame Spacing adaptation routine being executed to modify the Inter Frame Spacing in real-time by ascertaining a transmit activity and a collision intensity when the transmit activity is greater than or equal to a transmit activity threshold, and by adjusting the Inter Frame Spacing until the collision intensity rises above a collision intensity threshold.