System and method for implementing ASI over long distances

• US 20070071005A1
• Filed: 09/26/2005
• Published: 03/29/2007
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: Jinsalas Solutions LLC (Intellectual Ventures LLC)
• Original Assignee: Jinsalas Solutions LLC (Intellectual Ventures LLC)
• Inventors: Mayhew, David, Comins, Todd
• Granted Patent: US 7,653,060 B2
• Time in Patent Office: Days
• 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 adapted to transmit a plurality of packets using a protocol which defines a perishable bit within each packet of said plurality of packets, said device comprising:

a first circuit for transmitting each of said plurality of packets to a destination, and

a storage element adapted to store only those transmitted packets in which said perishable bit is not asserted.

2. The device of claim 1, further comprising a second circuit adapted 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, whereby said protocol defines a sequence number within each packet which is used to identify said packet, said device further comprising a third circuit adapted to retransmit one of said stored packets from said storage element to said destination in response to an indication that said one of said stored packets was not correctly received by said destination.

4. The device of claim 3, further comprising a fourth circuit adapted to alter the sequence numbers of said packets stored in said storage element.

5. The device of claim 3, 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.

6. The device of claim 3, wherein said indication is a signal indicating the expiration of a predetermined time period.

7. The device of claim 1, wherein said protocol is the Advanced Switching protocol.

8. The device of claim 7, further comprising a second circuit adapted to discard one of said transmitted packets from said storage element when said destination acknowledges receipt of said one of said transmitted packets.

9. The device of claim 7, whereby said protocol defines a sequence number within each packet which is used to identify said packet, said device further comprising a third circuit adapted to retransmit one of said stored packets from said storage element to said destination in response to an indication that said one of said stored packets was not correctly received by said destination.

10. The device of claim 9, further comprising a fourth circuit adapted to alter the sequence numbers of said packets stored in said storage element.

11. The device of claim 9, 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.

12. The device of claim 9, wherein said indication is a signal indicating the expiration of a predetermined time period.

13. A method of minimizing the size of a retry buffer used in the transmission of a plurality of packets utilizing a protocol defining a perishable bit within each packet, said method comprising the steps of:

transmitting one of said plurality of packets;

determining if said perishable bit is asserted in said one of said plurality;

storing said one of said plurality of packets if said determination indicates said perishable bit is not asserted;

discarding said one of said plurality of packets if said determination indicates said perishable bit is asserted; and

repeating said transmitting, determining, storing and discarding steps for each of said plurality of packets.

14. The method of claim 13, whereby said protocol is the Advanced Switching protocol.