Two-level switch-based load balanced scheduling method

Abstract

The invention discloses a two-level switch-based load balanced scheduling method, which comprises the following steps that first-level input ports buffer arriving cells in a virtual output queue (VOQ) according to destination ports; a scheduler switches messages to second-level input ports through a first-level switching network, wherein k cells from the same stream in the VOQ are called unit frames; each first-level input port executes minimum length scheduling according to a traffic distribution matrix, and transmits the unit frames of the same stream to a fixed mapping area of the stream through the first-level switching network in k continuous external timeslots; and N second-level input ports are sequentially divided into N / k groups of which each comprises k continuous second-level input ports forming an area, and each area buffers the cells in an output queue (OQ) according to the destination ports, and switches the cells to the destination output ports through a second-level switching network. The method has the advantages that a scheduling process is simple, computation or communication is not required, the method is easily implemented by hardware, the throughput of 100 percent is ensured, the sequence of the messages can be ensured, and the like.

Description

technical field [0001] The invention mainly relates to the field of message scheduling in a parallel switching structure, in particular to a message scheduling method for realizing load balancing and message order preservation in a parallel switching structure. Background technique [0002] Researchers have done a lot of research on packet out-of-sequence behavior by using active measurement and passive measurement methods. J.Bennet measured the out-of-sequence of packets at the switching center of MAE-East ISP, and found that in the measurement environment with heavy load and high parallelism of network equipment, the out-of-sequence of packets is very serious, and more than 90% of the connections have out-of-sequence . J.Bennett analyzed that the high out-of-sequence rate mainly comes from the local parallel processing mechanism inside the network, including parallel switching devices and parallel transmission links, and pointed out that packet out-of-order is not a patho...

AI Technical Summary

Problems solved by technology

However, when the traffic becomes unpredictable and changes dynamically, it is difficult to meet the centralized scheduling requirements under large switch sizes

The parallel matching scheduling method realizes message order preservation by transferring request-permission tokens between the first-level input line card and the second-level input line card, but in the specific hardware implementation, the frequent transfer of tokens between line cards will become a problem. Doubling the scheduling cycle

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