Carrier Class Resilience Solution For Switched Ethernet Local Area Networks (Lans)

A switch comprising:

• a control system;
• a first switch matrix;
• and
• a second switch matrix;
• wherein the first switch matrix has a first state machine associated with a first link and the second switch matrix has a second state machine associated with a second link;
• wherein the first switch matrix sends and/or receives on the first link, a plurality of Protocol Data Units (PDUs) and/or a plurality of response PDUs, which are used to drive the first state machine to verify a status of the first link;
• and
• wherein the second switch matrix sends and/or receives on the second link a plurality of PDUs and/or a plurality of response PDUs which are used to drive the second state machine to verify a status of the second link.

A resilient network comprising:

• an application blade;
• and
• a switch that includes:
• a control system;
• a first switch matrix;
• and
• a second switch matrix;
• wherein the first switch matrix has a first link to an application blade and the second switch matrix has a second link to the application blade;
• wherein the first switch matrix has a state machine and the application blade has a state machine where both of these state machines are associated with the first link used to connect the first switch matrix and the application blade;
• wherein the second switch matrix has a state machine and the application blade has a state machine where both of these state machines are associated with the second link used to connect the second switch matrix and the application blade;
• wherein the first switch matrix and the application blade exchange Protocol Data Units (PDUs) and response PDUs which are used to drive the state machines associated with the first link to verify a status of the first link used to connect the first switch matrix and the application blade;
• and
• wherein the second switch matrix and the application blade exchange PDUs and response PDUs which are used to drive the state machines associated with the second link to verify a status of the second link used to connect the second switch matrix and the application blade.

A method for providing resilient connectivity in a network that includes an application blade and a switch, wherein the switch includes:

• a control system:
• a first switch matrix;
• and
• a second switch matrix,
• wherein the first switch matrix has a first link to an application blade and the second switch matrix has a second link to the application blade;
• wherein the first switch matrix has a state machine and the application blade has a state machine where both of these state machines are associated with the first link used to connect the first switch matrix and the application blade;
• and
• wherein the second switch matrix has a state machine and the application blade has a state machine where both of these state machines are associated with the second link used to connect the second switch matrix and the application blade;
• wherein the method comprises the steps of:
• exchanging between the first switch matrix and the application blade, a plurality of Protocol Data Units (PDUs) and a plurality of response PDUs which are used to drive the state machines associated with the first link to verify a status of the first link used to connect the first switch matrix and the application blade;
• and
• exchanging between the second switch matrix and the application blade a plurality of PDUs and a plurality of response PDUs which are used to drive the state machines associated with the second link to verify a status of the second link used to connect the second switch matrix and the application blade.