Virtual tunnel endpoints for congestion-aware load balancing

A non-transitory computer-readable storage medium that includes a set of instructions which, in response to execution by a processor of a host, cause the processor to implement a source virtual tunnel endpoint (VTEP) to perform a method of congestion-aware load balancing in a data center network that includes the source VTEP, a destination VTEP, a source endpoint, a destination endpoint and multiple intermediate switches, wherein the host supports the source VTEP, and the method comprises:

• learning, by the source VTEP based on first packets from the destination VTEP, congestion state information associated with a plurality of paths provided by respective multiple intermediate switches connecting the source VTEP with the destination VTEP, wherein the congestion state information includes a mapping among the plurality of paths, a plurality of outer source port numbers corresponding to the plurality of paths, and congestion status for the plurality of paths;
• receiving, by the source VTEP, second packets that are sent by the source endpoint and destined for the destination endpoint associated with the destination VTEP;
• selecting, by the source VTEP, a particular path from the plurality of paths based on the congestion state information;
• generating, by the source VTEP, encapsulated second packets by encapsulating each of the second packets with header information that includes a set of tuples associated with the particular path, wherein the encapsulating each of the second packets comprises:
• determining, from the plurality of outer source port numbers, a particular outer source port number associated with the particular path;
• and
• configuring the set of tuples in the header information in each of the second packets to include the particular outer source port number;
• and
• sending, by the source VTEP, the encapsulated second packets to the destination endpoint such that the encapsulated second packets are forwarded via the particular path based on the set of tuples.

A switch configured to implement a source virtual tunnel endpoint (VTEP) to perform congestion-aware load balancing in a data center network, wherein the switch comprises:

• one or more first ports to receive first packets from a destination VTEP connected to the source VTEP via a plurality of paths provided by respective multiple intermediate switches connecting the source VTEP with the destination VTEP;
• a second port to receive second packets that are sent by the source endpoint and destined for the destination endpoint associated with the destination VTEP;
• and
• the switch is configured to:
• learn congestion state information associated with the multiple paths based on the first packets, wherein the congestion state information includes a mapping among the plurality of paths, a plurality of outer source port numbers corresponding to the plurality of paths, and congestion status for the plurality of paths;
• in response to receiving the second packets, select a particular path from the plurality of paths based on the congestion state information;
• generate encapsulated second packets by encapsulating each of the second packets with header information that includes a set of tuples associated with the particular path, wherein the encapsulating each of the second packets comprises:
• determining, from the plurality of outer source port numbers, a particular outer source port number associated with the particular path;
• and
• configuring the set of tuples in the header information in each of the second packets to include the particular outer source port number;
• and
• send the encapsulated second packets to the destination endpoint such that the encapsulated second packets are forwarded via the particular path based on the set of tuples.