The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 2002
Filed:
Apr. 14, 1998
Takao Yoshida, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A test system which can verify the internal connectivity in an ATM switching system by using loopback OAM cells, without establishing any dedicated channels or using special cells newly defined for test purposes. The connectivity test system produces a loopback OAM cell containing a local subsystem identifier in a predetermined field thereof to designate a specific local subsystem in the ATM switching system as the intended loopback point. This loopback OAM cell is transmitted to the ATM switching system by a transmission unit. A response unit, disposed in each local subsystem in the ATM switching system, receives the loopback OAM cell from the transmission unit through a certain physical link, and it checks the predetermined field of the received loopback OAM cell. If the identifier found in the field agrees with the local subsystem's own identifier, the response unit sends back the received loopback OAM cell through the same link so that it will be returned to the originator via the same route.