Forwarding path determining method, apparatus, and system

A method implemented by a first forwarding node and comprising:

• obtaining first link status information of a physical network and second link status information of a first virtual network;
• replacing a first main interface between the first forwarding node and a next-hop node of the first forwarding node with a first sub-interface, wherein the first main interface is between the first forwarding node and the next-hop node in the physical network, wherein the first sub-interface is between the first forwarding node and the next-hop node in the first virtual network, and wherein the first virtual network is over the physical network;
• and
• generating a forwarding entry to a second node in the first virtual network,
• wherein the forwarding entry comprises indication information of the first sub-interface, and
• wherein the second node is a destination node of data transmission.

A path computation node comprising:

• a memory configured to store instructions;
• and
• a processor coupled to the memory and configured to execute the instructions to:
• determine a first segment routing-best effort (SR-BE) forwarding path from a first node to a second node in a first virtual network, wherein the first node is a start node of data transmission, and wherein the second node is a destination node of the data transmission;
• determine a second SR-BE forwarding path from the first node to the second node in a physical network, wherein the first virtual network is over the physical network;
• and
• determine, when the first SR-BE forwarding path completely overlaps the second SR-BE forwarding path, the first SR-BE forwarding path as a target forwarding path;
• or when the first SR-BE forwarding path does not completely overlap the second SR-BE forwarding path:
• determine a first segment routing-traffic engineering (SR-TE) forwarding path according to the physical network and the first virtual network, and
• determine the first SR-TE forwarding path as the target forwarding path.