Protection Switching Method and Node

A first end node, comprising:

• a cross-connect board;
• a first optical transport network (OTN) communication board connected to the cross-connect board and configured to communicate on an OTN;
• and
• a main control board connected to the cross-connect board and the first OTN communication board, wherein the main control board is configured to control the first OTN communication board to:
• send a first protection switching request message to an intermediate node in response to a fault occurring on a working trail between the first end node and a second end node, wherein a protection trail of the working trail comprises the first end node, the second end node, and at least one intermediate node;
• and
• receive a second protection switching request message from the intermediate node;
• wherein the main control board is further configured to control the cross-connect board to switch service data to the protection trail for transmission in response to the second protection switching request message;
• wherein one overhead frame of each of the first protection switching request message and the second protection switching request message comprises at least two overhead information groups, and each of the at least two overhead information groups comprises a request type field, a request signal identifier field, and a bridge flag field;
• and
• wherein the request type field indicates a fault type of the working trail, wherein the request signal identifier field indicates a service identifier of a service that requests a protection resource, and wherein the bridge flag field indicates whether the protection resource corresponding to the service identifier indicated by the request signal identifier field has been bridged.

An intermediate node, comprising:

• a cross-connect board;
• one or more optical transport network (OTN) communication boards connected to the cross-connect board and configured to communicate on an OTN;
• and
• a main control board connected to the cross connect board and the one or more OTN communication boards, wherein the main control board is configured to control the one or more OTN communication boards to:
• receive a first protection switching request message from a first end node in response to a fault occurring on a working trail between the first end node and a second end node, wherein a protection trail of the working trail comprises the first end node, the second end node, and the intermediate node;
• send the first protection switching request message to a downstream, adjacent, node of the intermediate node;
• receive a second protection switching request message from the downstream adjacent node of the intermediate node;
• and
• send a second protection switching request message to the first end node;
• wherein one overhead frame of the first protection switching request message and the second protection switching request message comprises at least two overhead information groups, wherein each of the at least two overhead information groups comprises a request type field, a request signal identifier field, and a bridge flag field, wherein the request type field indicates a fault type of the working trail, wherein the request signal identifier field indicates a service identifier of a service that requests a protection resource, and wherein the bridge flag field indicates whether the protection resource corresponding to the service identifier indicated by the request signal identifier field has been bridged.