ATM switch in dual switch plane operation
AssigneeNorthern Telecom Limited
InventorRichard T. McGill
Life of this patent
Estimating the term…
Abstract
A novel ATM switch of dual switch plane operation and method of switching traffic in unit cells among ports in dual switch planes are disclosed. The ATM switch of the invention is plane protected in that a redundant switch plane is provided. In the switch, traffic cells are tagged either symmetric or asymmetric at an ingress port so that a destination port is able to properly gather correct cells even when switch planes develop faults or quality degradation.
Claims12
An ATM switch of dual switch plane operation for exchanging cells among a plurality of bidirectional ports through a first and a second switch plane, comprising:
- each of the plurality of bidirectional ports connected to a plurality of linecards to receive the cells therefrom and transmit the cells thereto,
- a first and a second switch fabric for transferring the cells among the plurality of bidirectional ports, the first switch fabric being in the first switch plane and the second switch fabric being in the second switch plane,
- said plurality of bidirectional ports connected to first and second switch fabrics for transferring the cells among the plurality of bidirectional ports,
- each of the bidirectional ports having tagging means for tagging each cell either symmetric or asymmetric and having transmitting means for transmitting symmetric cells to both switch fabrics and asymmetric cells to only one of the two switch fabrics, and
- each of the bidirectional ports having receiving means for accepting symmetric cells from one of the two switch fabrics and asymmetric cells from either of the two switch fabrics.
A method of exchanging ATM cells among a plurality of bidirectional ports by way of a first switch fabric in a first switch plane and a second switch fabric in a second switch plane comprising steps of:
- each of the plurality of bidirectional ports receiving the cells from a plurality of linecards and transmitting the cells thereto;
- each of the bidirectional ports tagging each cell either symmetric or asymmetric and transmitting symmetric cells to the switch fabric in both switch planes and asymmetric cells to the switch fabric in only one of the two switch planes;
- and
- each of the bidirectional ports accepting symmetric cells from the switch fabric in one of the two switch planes and asymmetric cells from the switch fabrics in either of the two switch planes.
Dependencies are inferred from the claim text.