Device and method for managing oversubscription in a network

• US 20070268823A1
• Filed: 12/20/2006
• Published: 11/22/2007
• Est. Priority Date: 08/30/2004
• Status: Abandoned Application

• Current Assignee: Ken Madison, Marek Thalka, Mathew Steinberg, Poly Palamuttam, Ravinder Sajwan
• Original Assignee: Ken Madison, Marek Thalka, Mathew Steinberg, Poly Palamuttam, Ravinder Sajwan
• Inventors: Thalka, Marek, Steinberg, Mathew, Palamuttam, Poly, Madison, Ken, Sajwan, Ravinder
• Application Number:
  US11/643,339
• Publication Number:
  US 20070268823A1
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/527 Quantum based scheduling, e.g. credit or deficit based scheduling or token bank
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin

Abstract

A device and a method for aggregating and managing large quantities of data are disclosed. The received data are prioritized into high and low priority queues. The device receive memory is partitioned into blocks which are further divided into free list and allocation list. The low priority queues occupy between 1 and 48 blocks and the high priority queues occupy between 1 and 32 blocks. The incoming data are further subjected to Weighted Random Early Detection (WRED) process that controls congestion before it occurs by dropping some of the queues. The stored data are read using Modified Deficit Round Robin (MDRR) approach. The invention further employees several different filtering approaches for prioritizing data.

Claims

17. A device for transmitting data, said device comprising:

at least one physical (PHY) layer located on ingress side of said device;

at least one media access control (MAC) device;

at least one Reduced Medium-independent Interface (RMII), a Reduced Gigabit medium-Independent Interface (RGMII), a Serial Gigabit Media Independent Interface (SGMII), 10 GigabitAttachment Unit Interface (XAUI) or 10 Gigabit Small Form-factor Pluggable Electrical Interface (XFI);

a flow control mechanism, a memory; and

a data sending unit.

1. A method for transmitting data, said method comprising:

receiving said data from at least one source;

determining priority level of said data from code instructions transmitted with said data;

selectively dropping a portion of said data;

determining available memory resources for the remainder of said data;

selecting the memory resources for recording the remainder of said data;

recording the remainder of said data into said memory resources;

reading the stored data from said memory resources;

and sending said data out of the memory resources.

2. The method claim 1 wherein said code instructions comprise at least:

multi protocol label switching, multi protocol label switching EXP field, inner vLAN, outer vLAN, destination address, source address, multicast destination address, layer 2 Ethertype, link layer control, encoding, sub network access protocol encoding, internet protocol, internet protocol version, differential service code point or layer 3 protocol.

3. The method of claim 1 wherein said data are Ethernet frames received at 10 Megabits per second (Mbps), 100 Mbps, 1 Gigabit per second (Gbps) or 10 Gbps.

4. The method of claim 1 wherein said data are free of said code instructions.

5. The method of claim 1 wherein a portion of said data are dropped by Weighted Random Early Detection (WRED) approach.

6. The method of claim 1 wherein no data are dropped at 1 Gbps transmission rate for interfaces operating at 1 Gbps.

7. The method of claim 1 wherein no data are dropped at 10 Gbps transmission rate for interfaces operating at 10 Gbps.

8. The method of claim 1 wherein said memory resources are partitioned in 1 Kilobyte blocks.

9. The method of claim 1 wherein said memory resources are external to the invention.

10. The method of claim 9 wherein said external memory resources are partitioned in 4 Kilobyte blocks.

11. The method of claim 1 wherein said memory operates at between approximately 100 Megahertz and approximately 200 Megahertz.

12. The method of claim 1 wherein said reading from said memory resources is performed at 155 MHz.

13. The method of claim 1 further partitioning said available memory resources into a free list and an allocation list.

14. The method of claim 5 wherein said data are dropped when exceeding a pre-selected threshold level.

15. The method of claim 13 further comprising updating said free list and said allocation list.

16. The method of claim 1 wherein said reading the stored data further comprises Modified Reduced Deficit Round Robin (MDRR) servicing.

18. The device of claim 17 wherein said at least one PHY layer is three PHY layers and wherein said at least one MAC is three MACs.

19. The device of claim 17 wherein said at least one PHY layer is an 8 port device.

20. The device of claim 17 wherein said at least one PHY layer is a 24 port device.

21. The device of claim 17 wherein said memory is 256 KB memory.

22. The device of claim 17 wherein said memory is 384 KB memory.

23. The device of claim 17 wherein said memory is 480 KB memory.

24. The device of claim 17 wherein said memory is a dual ported Random Access Memory (RAM).

25. The device of claim 17 wherein said memory is partitioned into 1 KB memory blocks.

26. The device of claim 25 wherein said external memory is partitioned into 4 KB memory blocks.

27. The device of claim 17 further comprising a System Packet Interface Level 4 Phase 2 (SPI 4.2) device.

28. The device of claim 17 further comprising a XAUI interface as the system-side interface.

25-1. The device of claim 17 wherein said memory is used to contain allocation information for external memory blocks.

30. Device for transmitting data, said device comprising:

means for receiving said data;

means for prioritizing said data;

means for selectively dropping some of said data;

means for writing said data into a memory;

means for reading said written data from said memory; and

means for sending said written data from said memory.