Link protection method in SDN, switching device, and network controller

A link-protection method in a software-defined network (SDN), the link-protection method comprising:

• performing, by a network controller in the SDN, network link signaling negotiation to establish a communications link with a first destination device;
• performing, by the network controller, network link signaling negotiation to establish a communications link with a second destination device;
• obtaining, by the network controller, first information and link protection information, wherein the first information includes a network link signaling negotiation result between the network controller and the first destination device and a network link signaling negotiation result between the network controller and the second destination device, wherein the first information further instructs a first switching device in the SDN to establish communication links between the first switching device and the first destination device and between the first switching device and the second destination device, wherein the link protection information instructs the first switching device to proactively and automatically perform primary-to-secondary link switching when a link is faulty, wherein the first switching device is controlled by the network controller, and wherein the first information contains type information of a to-be-established link and status information of the to-be-established link, and at least one of information about an access controller (AC) side link, an AC bound interface, a pseudowire (PW) side link, PW incoming label information, PW outgoing label information, peer address information, a time to live (TTL) value, a maximum transmission unit (MTU), or a link encapsulation type;
• and
• sending, by the network controller, the first information and the link protection information to the first switching device to instruct the first switching device to establish a primary link with a first destination device and a secondary link with a second destination device according to the network link signaling negotiation results between the network controller, the first destination device, and the second destination device.

A switching device, comprising:

• a bus;
• a memory coupled to the bus and configured to store an instruction;
• a receiver coupled to the bus and configured to receive first information and link protection information from a network controller in software-defined networking (SDN), wherein the first information includes a network link signaling negotiation result between an SDN controller (SNC) and a first destination device and a network link signaling negotiation result between the SNC and a second destination device, wherein the first information further instructs the switching device to establish communication links between the switching device and the first destination device and between the switching device and the second destination device, wherein the link protection information instructs the switching device to proactively and automatically perform primary-to-secondary link switching when a link is faulty, wherein the first information contains the type information of a to-be-established link, and status information of the to-be-established link, and wherein the type information of the to-be-established link further comprises information about a virtual private local area network service (VPLS), a single-end or a multi-end type;
• and
• a processor coupled to the bus, wherein the instruction causes the processor to be configured to:
• establish a primary link with the first destination device and a secondary link with the second destination device according to the network link signaling negotiation results between the SNC, the first destination device, and the second destination device;
• and
• determine, according to the link protection information, instructions to proactively and automatically perform the primary-to-secondary link switching.

A network controller, comprising:

• a bus;
• a transmitter coupled to the bus;
• a receiver coupled to the bus;
• a memory coupled to the bus and storing at least one instruction;
• a processor coupled to the bus, wherein the at least one instruction causes the processor to be configured to:
• perform network link signaling negotiation to establish communications with a first destination device via the transmitter and receiver;
• perform network link signaling negotiation to establish communications with a second destination device via the transmitter and receiver;
• obtain first information and link protection information, wherein the first information includes a network link signaling negotiation result between the network controller and the first destination device and a network link signaling negotiation result between the network controller and the second destination device, wherein the first information further instructs a first switching device in a software defined network (SDN) to establish communication links between the first switching device and the first destination device and between the first switching device and the second destination device, wherein the link protection information instructs the first switching device to proactively and automatically perform primary-to-secondary link switching when a link is faulty, wherein the first information contains the type information of a to-be-established link and status information of the to-be-established link, wherein the type information of the to-be-established link further comprises at least one of information about, a single-end or a multi-end type, and wherein the first switching device is controlled by the network controller;
• and
• send, via the transmitter, the first information and the link protection information to the first switching device to instruct the first switching device to establish a primary link with the first destination device and a secondary link with the second destination device according to the network link signaling negotiation results between the network controller, the first destination device, and the second destination device.