Queue management in a forwarder

Patent metadata

Field	Value
Publication number	US-11729108-B2
Application number	US-202117345289-A
Country	US
Kind code	B2
Filing date	Jun 11, 2021
Priority date	Dec 15, 2015
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A queue management method, system, and recording medium include Selective Acknowledgments (SACK) examining to examine SACK blocks of a forwarder to selectively drop packets in a forward flow queue based on a reverse flow queue and MultiPath Transmission Control Protocol (MPTCP) examining configured to perform a first examining to examine multipath headers to recognize MPTCP flows based on a comparison between two subflows being a part of a same superflow and a second examining to examine the reverse flow queue to determine if redundant data has been sent based on a result of the first examining, a packet in the forward flow queue from a prior transmission being dropped from the forward flow queue sent from the forwarder to a receiver if a metadata of the packet does not match a metadata of an acknowledged packet in the reverse flow queue.

First claim

What is claimed is:

1. A queue management system, comprising:
a processor; and
a memory, the memory storing instructions to cause the processor to execute:
Selective Acknowledgments (SACK) examining to examine SACK blocks of a forwarder to selectively drop packets in a forward flow queue based on a reverse flow queue by examining each packet in the forward flow queue to determine if it belongs to a same TCP flow as specified in the ACK packet of the reverse flow; and
MultiPath Transmission Control Protocol (MPTCP) examining configured to perform:
a first examining to examine multipath headers to recognize MPTCP flows based on a comparison between:
two subflows used simultaneously being a part of a same first superflow; and
a different set of two subflows simultaneously being a part of a same second superflow; and

a second examining to examine the reverse flow queue to determine if redundant data has been sent based on a result of the first examining,

wherein, as a result of the second examining, packets associated with the redundant data are dropped and allocated memory for the dropped packets is returned to the system,
further comprising extracting acknowledgement information from arriving packets in the forward flow queue at the forwarder,
wherein the first packet is prioritized when a triple acknowledgement is detected for the first packet.

2. A queue management method, comprising:
Selective Acknowledgments (SACK) examining to examine SACK blocks of a forwarder to selectively drop packets in a forward flow queue based on a reverse flow queue by examining each packet in the forward flow queue to determine if it belongs to a same TCP flow as specified in the ACK packet of the reverse flow; and
MultiPath Transmission Control Protocol (MPTCP) examining configured to perform:
a first examining to examine multipath headers to recognize MPTCP flows based on a comparison between:
two subflows used simultaneously being a part of a same first superflow; and
a different set of two subflows simultaneously being a part of a same second superflow; and

a second examining to examine the reverse flow queue to determine if redundant data has been sent based on a result of the first examining,

wherein, as a result of the second examining, packets associated with the redundant data are dropped and allocated memory for the dropped packets is returned to the system,
further comprising extracting acknowledgement information from arriving packets in the forward flow queue at the forwarder,
wherein the first packet is prioritized when a triple acknowledgement is detected for the first packet.

3. A non-transitory computer-readable recording medium recording a queue management program, the program causing a computer to perform:
Selective Acknowledgments (SACK) examining to examine SACK blocks of a forwarder to selectively drop packets in a forward flow queue based on a reverse flow queue by examining each packet in the forward flow queue to determine if it belongs to a same TCP flow as specified in the ACK packet of the reverse flow; and
MultiPath Transmission Control Protocol (MPTCP) examining configured to perform:
a first examining to examine multipath headers to recognize MPTCP flows based on a comparison between:
two subflows used simultaneously being a part of a same first superflow; and
a different set of two subflows simultaneously being a part of a same second superflow; and

a second examining to examine the reverse flow queue to determine if redundant data has been sent based on a result of the first examining,

wherein, as a result of the second examining, packets associated with the redundant data are dropped and allocated memory for the dropped packets is returned to the system,
further comprising extracting acknowledgement information from arriving packets in the forward flow queue at the forwarder,
wherein the first packet is prioritized when a triple acknowledgement is detected for the first packet.

4. The queue management system of claim 1 , wherein the examining each packet examines metadata and TCP options of each packet.

5. The system of claim 1 , further comprising a Transmission Control Protocol (TCP) receiver using the SACK blocks that communicates with the receiver about an acknowledged packet.

6. The system of claim 1 , further comprising:
prioritizing, based on the triple duplicate acknowledgement, the first packet of the packets in the forward flow queue by moving the first packet to a head of the queue so that it is next in line for transmission to the receiver.

7. The system of claim 6 , wherein, as a result of the prioritizing, allocated memory for a dropped packet is returned to the system.

8. The system of claim 1 ,
wherein the forwarder keeps track of a state of the acknowledged packet.

9. The system of claim 1 ,
further comprising a Transmission Control Protocol (TCP) receiver using SACK blocks that communicates with the receiver about the acknowledged packet.

Assignees

• IBM

Inventors

• Le Thai Franck
• Nahum Erich M

Classifications

• H04L47/627 Primary

  policing · CPC title

• H04L47/32 Primary

  by discarding or delaying data units, e.g. packets or frames · CPC title

• H04L47/40

  using split connections · CPC title

• H04L47/6255

  queue load conditions, e.g. longest queue first · CPC title

• H04L47/6275

  based on priority · CPC title