US 6,560,232 B1Granted

ATM switch and switching method capable of avoiding collision between cells

AssigneeNEC Corporation

InventorTsugio Sugawara

Life of this patent

Estimating the term…

Loading patent…

Abstract

First to fourth input buffers stores cells inputted from first to fourth input ports, respectively. Each input buffer is equipped with a main buffer section, a plurality of sub-buffer sections connected to the main buffer section in series and a buffer controller for controlling them. A collision judging section judges whether or not a collision occurs between the cells outputted from each sub-buffer section, and the judged result is sent to a cell converter. The cell converter returns a collision information to the buffer controller in accordance with the judged result, and further sends a cell, which has a victory information since it is judged as a victory over the collision, through a sorter to a self-routing section. The self-routing section outputs the received cell to an output port. This configuration enables a shuffle operation to be carried out in the sub-buffer section and the cell converter to thereby avoid the drop of the throughput.

Claims18

Dependent claims

An ATM switch comprising:

an input port which sequentially receives ATM cells;
a main buffer section which stores the ATM cells received by said input port and outputs the stored ATM cells in an order of the reception;
a sub-buffer section which stores the ATM cells from said main buffer section and shuffles the ATM cells stored in said sub-buffer and outputs the shuffled ATM cells;
a collision judging section which judges whether or not a collision between the ATM cells outputted from said sub-buffer section occurs and judges whether each of the colliding ATM cells is a victory ATM cell or a defeat ATM cell when the occurrence of the collision is judged, the ATM cells other than said colliding ATM cells being non-collision ATM cells;
a buffer controller which controls said sub-buffer section based on the judging result by said collision judging section such that said victory ATM cell and said non-collision ATM cells are outputted and said defeat ATM cell is stored and held in said sub-buffer section;
and
a routing section which performs a routing operation to each of said victory ATM cell and said non-collision ATM cells from said collision judging section to output from a predetermined output port.

4 more elements

An ATM switching method comprising:

(A) storing ATM cells sequentially received by an input port into a main buffer section;
(B) outputting the ATM cells stored in said main buffer section in an order of the reception;
(C) storing the ATM cells from said main buffer section into a sub-buffer section;
(D) shuffling the ATM cells stored in said sub-buffer and outputting the shuffled ATM cells;
(E) judging whether or not a collision between the ATM outputted from said sub-buffer section occurs, and judging whether each of the colliding ATM cells is a victory ATM cell or a defeat ATM cell when the occurrence of the collision is judged, the ATM cells other than said colliding ATM cells being non-collision ATM cells;
(F) controlling said sub-buffer section based on the judging result at said step (E) such that said victory ATM cell and said non-collision ATM cells are outputted and said defeat ATM cell is stored and held in said sub-buffer section;
and
(G) performing a routing operation to each of said victory ATM cell and said non-collision ATM cells outputted from said sub-buffer section to send from a predetermined output port.

5 more elements

Dependencies are inferred from the claim text.