Adaptive transmit window control mechanism for packet transport in a universal port or multi-channel environment

• US 7,583,594 B2
• Filed: 01/31/2003
• Issued: 09/01/2009
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Telogy Networks, Inc. (Texas Instruments, Inc.)
• Original Assignee: Texas Instruments, Inc.
• Inventors: Zakrzewski, Adrian
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): HAN, CLEMENCE S
• Application Number:
  US10/355,053
• Publication Number:
  US 20040151113A1
• Time in Patent Office: 2,405 Days
• Field of Search: None
• US Class Current: 370/229
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]

Abstract

The transmit window size of a Simple Packet Relay Transport protocol packet transmission system can determine the efficiency of transmission and the memory requirements of the transmitter. A sufficiently large transmit window must be maintained to avoid transmission waits which can reduce the utilization of available transmission path bandwidth. However, an oversize window will require excess buffer capacity and therefore utilize additional storage space on the transmitter. A balance in window size is dynamically achieved through monitoring of the buffer write operations to determine the accessibility of the transmit buffer based upon packet transmission utilization and packet consumption acknowledgment.

Claims

1. A method for dynamic configuration of a size of a dynamic transmit window in a transmitter of a Simple Packet Relay Transport protocol message communication system, comprising:

establishing a minimum window size value and a maximum window size value;

constraining the size of said dynamic transmit window between said minimum size value and said maximum size value;

monitoring packet consumption acknowledgement as a reflection of a current round trip time of travel (RTT) of a packet transmitted in said communication system;

determining the size of said dynamic transmit window based upon said monitored packet consumption acknowledgement and a data rate of said packet, where the data rate is established in bits per unit time and the dynamic window size is equal to the data rate times the length of said RTT, further comprising;

monitoring window write failures and an absence of window write failures in said dynamic transmit window during transmission; and

utilizing maximum available bandwidth while minimizing buffer capacity requirements of a buffer by dynamically adjusting said size of said dynamic transmit window and corresponding allocated memory space in said buffer as needed, based upon said monitoring of window write failures and the absence of window write failures.

2. The method of claim 1, further including:

matching said dynamic transmit window size to said reflection of said RTT and said data rate prior to said monitoring of window write failures.

3. The method of claim 1, further comprising:

increasing the size of said dynamic transmit window when the number of window write failures within a predetermined time period exceed a threshold.

4. The method of claim 1, further comprising:

monitoring said dynamic transmit window to determine if said dynamic transmit window has reached a full state; and

decreasing the size of said dynamic transmit window when the dynamic transmit window is in a partial full state for a percentage of time exceeding a predetermined threshold.

5. A method for dynamic configuration of a size of a dynamic transmit buffer in a transmitter of a Simple Packet Relay Transport protocol message communication system, comprising:

establishing a dynamic transmit buffer connected to a network;

transmitting a plurality of packets, said plurality of packets having a first packet and a last packet, from said transmit buffer at a transmit time, across said network to a receiver;

receiving consumption acknowledgement of said packets at a consumption acknowledgement time from said receiver;

monitoring a round trip time of travel of said packets based upon the difference between said transmit time and said consumption acknowledgement time;

determining a data transmission rate of said communication network;

establishing a size of said dynamic transmit buffer based upon said monitored round trip time and said data transmission rate of said packet established in bits per unit time, and the dynamic transmit buffer size is equal to the data transmission rate times the length of said monitored round trip time; and

wherein said size of said dynamic transmit buffer is established between a downsize threshold and an upsize threshold to constrain said dynamic transmit buffer to contain sufficient packets to continue transmission of said last packet substantially contemporaneous with the receipt of a consumption acknowledgment of said first packet is received at said transmitter to thereby maximize bandwidth utilization while minimizing a capacity of said dynamic transmit buffer.

6. A method for dynamic configuration of a size of a dynamic transmit window in a transmitter of a Simple Packet Relay Transport protocol message communication system, comprising:

monitoring packet rejection based on results of a packet send function;

determining a current rate of packet rejection;

maximizing bandwidth utilization while minimizing buffer capacity requirements of a buffer by adjusting said size of said dynamic transmit window and corresponding allocated memory space in said buffer, based upon said determined current rate of packet rejection;

wherein;

said size of said dynamic transmit window and corresponding allocated memory space in said buffer is reduced when the current rate of packet rejection is below a downsize threshold.

7. The method of claim 6, wherein

said increase in said size of said dynamic transmit window is implemented when the current rate of packet rejection exceeds an upsize threshold.