Fault detection in multi-plane switch

(54) FAULT DETECTION IN MULTI-PLANE SWITCH

(75) Inventors: Mats Lindblom, Johanneshov (SE);

Hans Berghager, Alvsjo (SE); Per
Sydhoff, Stockholm (SE)

(73) Assignee: Telefonaktiebolaget LM Ericsson
(publ), Stockholm (SE)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 690 days.

(21) Appl. No.: 09/688,165

(22) Filed: Oct. 16, 2000

(51) Int. CI.7 G01R 31/08

(52) U.S. CI 370/219; 370/337; 370/244

(58) Field of Search 370/216-220,

370/399, 241.1, 244, 375.2, 236.2, 387, 395.1; 340/2.23, 223; 714/2; 374/2

(56) References Cited

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FOREIGN PATENT DOCUMENTS

WO 99/45688 A2 9/1999

OTHER PUBLICATIONS

Miyaho et al, "ATM Switching Mode System Technology for Effective Maintainability", Globecom '95, IEEE Global Telecommunications Conference, Singapore, Nov. 14-16, 1995, New York, vol. 3, Nov. 14, 1995, pp. 1719-1723.

* cited by examiner

Primary Examiner—Kenneth Vanderpuye

Assistant Examiner—Ian N. Moore

(74) Attorney, Agent, or Firm—Nixon & Vanderhye, PC.

A cell switch node (20) has a first switch plane (22); a second switch plane (24); a sender switch port interface unit (26s); and a receiver switch port interface unit (26^). The sender switch port interface unit sends maintenance cells to the receiver switch port interface unit via the first switch plane and the second switch plane. The maintenance cells are applied to the first switch plane and the second switch plane in a predetermined sequence. The receiver switch port interface unit detects an erroneous switch plane when the maintenance cells from the sender switch port interface unit do not arrive in the predetermined sequence.

12 Claims, 16 Drawing Sheets