Efficient multicast forward method based on sliding window in share memory switching structure

Abstract

The invention belongs to a front end switching technology of an Ethernet switching system, in particular relates to a high-efficiency group-broadcasting repeat method based on a sliding window in a shared storage switching structure. The method adopts an optimization way outputting the sliding window and no longer uses a strict FIFO-type cell to make a repeat, but selects a suitable cell to make the repeat in a certain range (window width). The repeat way obviously decreases the repeat span of a group-broadcasting cell, thereby decreasing the stay time of the group-broadcasting cell in a shared storage area. The method has two most direct advantages that the method increases the synchronous level of the group-broadcasting cell repeat at every goal port, and lowers the consumption to a shared storage room. An analogue result shows that selecting the suitable window width can effectively increase the performances of the system at the two fields, but excessively widening the window width can not limitlessly increase the performances of the system, on the contrary, can increase the count complication.

Description

technical field [0001] The invention belongs to the front-end switching technology of an Ethernet switch system, in particular to an efficient multicast forwarding method based on a sliding window in a shared storage switching structure. Background technique [0002] Crossbar is a switching fabric widely used in high-speed backplane switching. An M*N Crossbar switching structure has M input ports and N output ports, and the M input ports and N output ports form M*N intersecting switches. If the i-th input port and the j-th output port The switch at the intersection is closed, and the i-th input port and the j-th output port form a path, thus forming an exchange from input port i to output port j. Obviously, at any moment, each input port can only be closed to a cross switch with one output port. The usual Crossbar structure has the same number of input and output ports, because if M≠N, the crossbar closed at the same time depends on the smaller number of M, N. Figure 1 is...

AI Technical Summary

Problems solved by technology

In this regard, the researchers proposed a rotation strategy, a weighted rotation strategy and other schemes [3] , but this will cause head-of-line congestion of the multicast queue in many cases, because there is only one multicast queue

ACQ solves the congestion problem better, but it brings additional overhead, that is, in addition to the storage space of cells, additional address queues are required, and they all coexist in the public shared storage space

[0016] Another shortcoming of ACQ implemented in the form of FIFO (First In First Out) lies in its bottleneck of storage space utilization under high traffic pressure.

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