Packet transmission credit allocation

Patent metadata

Field	Value
Publication number	US-2019068515-A1
Application number	US-201715692891-A
Country	US
Kind code	A1
Filing date	Aug 31, 2017
Priority date	Aug 31, 2017
Publication date	Feb 28, 2019
Grant date	—

Abstract

Example implementations relate to packet transmission credit allocation. In some examples, a system may include a processing resource and a memory resource storing instructions executable by the processing resource to allocate a first amount of packet transmission credits from a destination node to a source node; determine a modification to the first amount of packet transmission credits allocated from the destination node to the source node based on a comparison of a quantity of redeemed packet transmission credits by the source node to a packet transmission credit threshold of the source node; adjust the modification based on a condition at a buffer associated with the destination node; and apply the adjusted modification to the first amount of packet transmission credits to produce a second amount of packet transmission credits to allocate from the destination node to the source node.

First claim

What is claimed:

1 . A system comprising:
a processing resource; and a memory resource storing instructions executable by the processing resource to:
allocate a first amount of packet transmission credits from a destination node to a source node;
determine a modification to the first amount of packet transmission credits allocated from the destination node to the source node based on a comparison of a quantity of redeemed packet transmission credits by the source node to a packet transmission credit threshold of the source node;
adjust the modification based on a condition at a buffer associated with the destination node; and
apply the adjusted modification to the first amount of packet transmission credits to produce a second amount of packet transmission credits to allocate from the destination node to the source node.

2 . The system of claim 1 , wherein the first amount of packet transmission credits is a baseline amount of packet transmission credits allocated to each of a plurality of source nodes in communication with the destination node.

3 . The system of claim 2 , wherein the baseline amount of packet transmission credits is a configurable static amount of packet transmission credits.

4 . The system of claim 1 , wherein the condition at the buffer is an amount of unoccupied storage space available at the buffer.

5 . The system of claim 1 , wherein the buffer is shared by a plurality of source nodes in communication with the destination node.

6 . The system of claim 1 , wherein the packet transmission credit threshold includes a first range of quantities of redeemed packet transmission credits corresponding to a packet transmission increment window.

7 . The system of claim 6 , wherein the packet transmission credit threshold includes a second range of quantities of redeemed packet transmission credits corresponding to a packet transmission credit increment level within the packet transmission increment window.

8 . The system of claim 1 , wherein the packet transmission credit threshold includes a first range of quantities of redeemed packet transmission credits corresponding to a packet transmission decrement window.

9 . The system of claim 8 , wherein the packet transmission credit threshold includes a second range of quantities of redeemed packet transmission credits corresponding to a packet transmission credit decrement level within the packet transmission decrement window.

10 . The system of claim 1 , wherein a packet transmission credit is equal to an amount of data storable on a reserved amount of storage space on the buffer.

11 . A non-transitory computer-readable medium containing instructions executable by a processing resource to cause the processing resource to:
allocate a first amount of packet transmission credits from a destination node to a source node of a plurality of source nodes utilizing a storage space on a buffer of the destination node; determine, based on an amount of the first amount of packet transmission credits redeemed by the source node and a congestion level of the storage space on the buffer, a second amount of packet transmission credits to allocate to the source node; adjust the second amount of packet transmission credits by an amount of the first amount of packet transmission credits not redeemed by the source node; and allocate the adjusted second amount of packet transmission credits from the destination node to the source node.

12 . The non-transitory computer readable medium of claim 11 , further comprising instructions executable to:
increase the adjusted second amount of packet transmission credits above a packet transmission credit baseline amount prior to allocating when the modified second amount of packet transmission credits is under the baseline amount of packet transmission credits.

13 . The non-transitory computer readable medium of claim 11 , wherein the instructions to determine the second amount of packet transmission credits based on the congestion level of the storage space on the buffer include instructions to:
reduce the second amount of packet transmission credits based on an amount of available storage space at the buffer falling below a threshold amount.

14 . The non-transitory computer readable medium of claim 11 , wherein the instructions to determine the second amount of packet transmission credits include instructions to:
retrieve the second amount of packet transmission credits from a first set of values if the amount of the first amount of packet transmission credits redeemed by the source node is in an increment window relative to the first amount of packet transmission credits; and retrieve the second amount of packet transmission credits from a second set of values when the amount of the first amount of packet transmission credits redeemed by the source node is in a decrement window relative to the first amount of packet transmission credits.

15 . A method comprising:
allocating a first amount of packet transmission credits from a destination node of a network switch to a source node of the network switch; determining whether a modification to the first amount of packet transmission credits will be an increase or a decrease in the first amount of packet transmission credits, based on a difference between the allocated first amount of packet transmission credits and a redeemed amount of the allocated first amount of packet transmission credits redeemed by the source node; determining an amount of the modification to the first amount of packet transmission credits based on a modification level assigned to the amount of the allocated first amount of packet transmission credits redeemed by the source node; adjusting the amount of the modification based on an amount of storage space available at a buffer of the destination node; and determining a second amount of packet transmission credits to allocate from the destination node to the source node by applying the adjusted amount of the modification to the first amount of packet transmission credits from a destination node of a network switch.

16 . The method of claim 15 , comprising:
refunding, to the destination node from the source node, the amount of the allocated first amount of packet transmission credits not redeemed by the source node after the source node has remained idle for a period of time.

17 . The method of claim 15 , comprising:
requesting, from a credit transfer manager local to the source node, to transfer a packet from the source node to the destination node.

18 . The method of claim 17 , comprising:
comparing the amount of data associated with the packet to an amount of packet transmission credits stored at the credit transfer manager for the source node.

19 . The method of claim 18 , comprising:
granting a permission to transfer the packet from the source node to the destination node when the amount of packet transmission credits stored at the credit transfer manager corresponds to at least as much reserved data storage space on the buffer of the destination node as the amount of data associated with the packet.

20 . The method of claim 18 , comprising:
dropping the packet at the source node when the amount of packet transmission credits stored at the credit transfer manager corresponds to less reserved data storage space on the buffer of the destination node than the amount of data associated with the packet.

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Seely Jonathan M
• Shillingburg Mark

Classifications

• H04L47/39 Primary

  Credit based · CPC title

• H04L49/9005

  using dynamic buffer space allocation · CPC title

• H04L47/32

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

• H04L47/783

  Distributed allocation of resources, e.g. bandwidth brokers · CPC title

• H04L47/30

  in combination with information about buffer occupancy at either end or at transit nodes · CPC title