Patent ID: 6999411

Claim:
A method of protection switching of redundant central arbiters in a router system, comprising: selecting an active central arbiter; selecting a standby central arbiter different from said active central arbiter; communicating the active status of said active central arbiter; communicating the standby status of said standby central arbiter; receiving at said active central arbiter requests to pass chunks of data through an optical switching fabric; at said active central arbiter in response to said requests concurrently issuing grants to pass said chunks and issuing optical switch configuration information corresponding to said grants, such that each said chunk passes during a single chunk period; at said standby central arbiter periodically receiving keep-alive requests; at said standby central arbiter concurrently issuing keep-alive grants and standby configuration information in response to said keep-alive requests; and interchanging said active and standby status of said respective active and standby central arbiters, such that said standby central arbiter becomes a new active central arbiter and said active central arbiter becomes a new standby central arbiter; wherein decisions of said selecting and said interchanging are initiated by a control processor selected from the group consisting of a master control processor (MCP) and shelf control processors, wherein said communicating of said active status occurs simultaneously from said active central arbiter to an optical switch ASIC and to a plurality of ingress ASICs; and said communicating of said standby status occurs simultaneously from said standby central arbiter to an optical switch ASIC and to a plurality of ingress ASICs, wherein said issuing grants and said issuing corresponding switch configuration information both occur within the same chunk period, wherein said issuing keep-alive grants and said issuing standby configuration information both occur within the same chunk period, wherein said requests received by said active central arbiter are issued from a plurality of ingress ASICs through first multiple links, wherein said grants issued by said active central arbiter are received by said plurality of ingress ASICs through said first multiple links, and wherein, if a grant is not received by said ingress ASIC within a predetermined timeout period after the corresponding request was issued, then said ingress ASIC resets an internal outstanding request queue as well as request queues in said active central arbiter, until the respective queues of both said ingress ASIC and said active central arbiter are emptied of all outstanding requests, such that said ingress ASIC and said active central arbiter are synchronized in an empty state.