System and method for implementing ASI over long distances

• US 7,653,060 B2
• Filed: 09/26/2005
• Issued: 01/26/2010
• Est. Priority Date: 09/26/2005
• Status: Expired due to Fees

• Current Assignee: Jinsalas Solutions LLC (Intellectual Ventures LLC)
• Original Assignee: Jinsalas Solutions LLC (Intellectual Ventures LLC)
• Inventors: Comins, Todd, Mayhew, David
• Primary Examiner(s): Shah; Chirag G
• Assistant Examiner(s): MITCHELL, DANIEL D
• Application Number:
  US11/235,346
• Publication Number:
  US 20070071005A1
• Time in Patent Office: 1,583 Days
• Field of Search: 370/235, 370/229, 370/351, 370/389, 370/392, 370/216
• US Class Current: 370/392
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/26 using explicit feedback to the source, e.g. choke packets

Abstract

The present invention provides a system and method for utilizing the Advanced Switching network protocol to communicate over long distances, such as multiple kilometers. The present invention utilizes an existing status bit, referred to as the Perishable Bit, within the AS packet header, to reduce the number of packets which must be stored in the retry buffer. This reduces the required size of the retry buffer and simultaneously reduces the latency associated with retransmitting time critical packets after NAKs are received. The receiving device also utilizes the Perishable Bit in determining which packets to accept and which to discard.

Claims

1. A device, comprising:

a first circuit configured to transmit each of a plurality of packets to a destination according to a protocol which defines a perishable bit within packets;

a storage element configured to store transmitted packets in which said perishable bit is not asserted until said device receives confirmation from said destination that said transmitted packets have been successfully received, and wherein the storage element is configured to not store transmitted packets in which said perishable bit is asserted;

a second circuit coupled to said storage element and configured to retransmit one or more packets from said storage element to said destination in response to receiving an indication that a particular packet of said transmitted packets that is within said storage element was not correctly received by said destination; and

a third circuit configured to sequentially renumber a sequence number of packets retransmitted after the particular packet, wherein the packets retransmitted after the particular packet are renumbered beginning with a next higher sequence number than the sequence number of the particular packet.

2. The device of claim 1, further comprising a fourth circuit configured to discard one of said transmitted packets from said storage element when said destination acknowledges receipt of said one of said transmitted packets.

3. The device of claim 1, wherein said indication is a packet received from said destination indicating that said one of said stored packets was not correctly received by said destination.

4. The device of claim 1, wherein said indication is a signal indicating the expiration of a predetermined time period.

5. The device of claim 1, wherein said protocol is the Advanced Switching Interconnect (ASI) protocol.

6. The device of claim 5, further comprising a fourth circuit configured to discard one of said transmitted packets from said storage element when said destination acknowledges receipt of said one of said transmitted packets.

7. A method, comprising:

a transmitting device transmitting a packet of a plurality of packets to a destination according to a protocol which defines a perishable bit within packets;

said transmitting device determining whether to store said packet in a retry buffer based on whether said perishable bit is asserted;

said transmitting device repeating said transmitting and determining for one or more remaining ones of said plurality of packets;

said transmitting device retransmitting at least one of said plurality packets from said retry buffer to said destination in response to receiving an indication that the at least one packet that is within said retry buffer was not correctly received by said destination; and

said transmitting device renumbering a sequence number of packets retransmitted after the at least one packet, wherein the packets retransmitted after the particular packet are renumbered beginning with a next higher sequence number than the sequence number of the at least one packet.

8. The method of claim 7, wherein said protocol is the Advanced Switching Interconnect (ASI) protocol.

9. The method of claim 7, farther comprising discarding one of the transmitted packets from the retry buffer in response to the destination acknowledging successful receipt of the one of the transmitted packets.

10. The method of claim 7, wherein said indication is a packet received from said destination indicating that said packet was not correctly received by said destination.

11. The method of claim 7, wherein said indication is a signal indicating the expiration of a predetermined time period.

12. A network device comprising:

a first circuit for transmitting each of a plurality of packets to a destination device, wherein each of the plurality of packets includes a header having that includes data indicating that the packet is perishable;

a storage element coupled to the first circuit and configured to store transmitted packets that are indicated by their corresponding headers as not being perishable but not store transmitted packets that are indicated by their corresponding headers as being perishable;

means for retransmitting one or more packets from the storage element to the destination device in response to receiving a retry indication from the destination device for a particular packet in the storage element, and for sequentially renumbering a sequence number of packets retransmitted after the particular packet, wherein the packets retransmitted after the particular packet are renumbered beginning with a next higher sequence number than the sequence number of the particular retransmitted packet.

13. The network device of claim 12, farther comprising means for discarding one of the transmitted packets from the storage element in response to the destination device acknowledging receipt of the packet.

14. The network device of claim 12, wherein the indication is a packet received from the destination device indicating that the packet was not correctly received by the destination device.

15. The network device of claim 12, wherein the indication is a signal indicating the expiration of a predetermined time period.