Fast media flow failover in layer 4 networks

A system for providing high availability network services in a communications network, the system comprising a plurality of network nodes including a network function implemented as two instances configured as an active instance and a backup instance, wherein the backup instance maintains state data such that the backup instance can actively provide services in response to a failure of the active instance, the system comprising:

• a processing system;
• and
• a memory storing computer-executable instructions thereupon which, when executed by the processing system, cause the system to perform operations comprising:
• receiving, by a pool of data forwarding functions implemented on the plurality of network nodes, ingress data packets addressed to the network function via a public network address;
• forwarding, by the pool of data forwarding functions over a tunnel connection, the ingress data packets to the network function based on an overlay network MAC address of the active instance;
• determining that the active instance has failed and that the backup instance will provide the network function, wherein determining that the active instance has failed comprises detecting a loss of a direct link between a forwarding node and an edge node hosting the active instance;
• removing an association between the overlay network MAC address and the edge node from a forwarding table without exchanging state information with the backup instance;
• and
• forwarding, by the pool of data forwarding functions over the tunnel connection, subsequent ingress data packets to the network function based on an overlay network MAC address of the backup instance without waiting for underlay routing updates.

A non-transitory computer-readable storage medium storing computer-executable instructions thereupon which, when executed by a processing system, cause the processing system to perform operations comprising:

• receiving, from a load balancer by a pool of data forwarding functions implemented on a plurality of nodes of a communication network, ingress data packets addressed to a network function via a public network address, wherein the communications network comprises a plurality of network devices including the network function implemented as two instances configured as an active instance and a backup instance, wherein the backup instance maintains state data such that the backup instance can actively provide services in response to a failure of the active instance;
• forwarding, by the pool of data forwarding functions over a tunnel connection, the ingress data packets to the network function based on an overlay network MAC address of the active instance;
• determining that the active instance has failed and that the backup instance will provide the network function, wherein determining that the active instance has failed comprises detecting a loss of a direct link between a forwarding node and an edge node hosting the active instance;
• removing an association between the overlay network MAC address and the edge node from a forwarding table without exchanging state information with the backup instance;
• forwarding, by the pool of data forwarding functions over the tunnel connection, subsequent ingress data packets to the network function based on a overlay network MAC address of the backup instance without waiting for underlay routing updates;
• and
• sending egress data packets directly to the load balancer.