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:
Jul. 20, 2004
Filed:
Apr. 30, 2002
Timothy M. Shanley, Orange, CT (US);
Thomas M. Preston, Middlebury, CT (US);
Eugene L. Parrella, Whitehouse Station, NJ (US);
Desikan V. Srinivasan, Naugatuck, CT (US);
Transwitch Corporation, Shelton, CT (US);
Abstract
An apparatus for avoiding head of line blocking in an ATM device includes a scheduler, at least one multicast queue, at least one unicast queue, a multicast session table, a multicast timer, and a problem PHY vector. The methods of the invention include alternate scheduling between multicast queue(s) and unicast queue(s). If a PHY device in a multicast session is inactive, it is skipped and the next PHY in the session is serviced. When the session has serviced all of the active PHYs and there remain only inactive PHYs in the session table, the session is ended. Preferably, a timer is started when only inactive PHYs remain in a session and the session is ended when the timer expires, if not sooner. Preferably, a problem PHY vector is maintained and updated at the end of each multicast session and when PHYs become active. The problem PHY vector includes a list of all of the presently inactive PHYs. The multicast session is preferably ended when the only PHYs remaining in the session are listed in the problem PHY vector.