Keep-alive technique in a network device

A network device comprising:

• a database configured to store data for one or more network sessions for the network device;
• one or more processors executing a keep-alive subsystem process, wherein the keep-alive subsystem process is configured to:
• read the database;
• determine, using data read from the database, a next transmission time associated with a network session from the one or more network sessions, wherein the next transmission time determines when to send a keep-alive packet for the network session;
• determine that the next transmission time is within a next time period from a current time;
• place, based on determining that the next transmission time is within the next time period, a identifier for the network session in a first bank of a timer queue of the network device, wherein the first bank stores identifiers for network sessions for which keep-alive packets are to be sent upon termination of the next time period;
• and
• transmit, using a packet processor of the network device, the keep-alive packet for the network session, wherein the keep-alive packet is sent within the next time period.

A non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more computing devices, cause the one or more computing devices to:

• read a database configured to store data for one or more network sessions for a network device;
• determine, using data read from the database, a next transmission time associated with a network session from the one or more network sessions, wherein the next transmission time determines when to send a keep-alive packet for the network session;
• determine that the next transmission time is within a next time period from a current time;
• place, based on determining that the next transmission time is within the next time period, a identifier for the network session in a first bank of a timer queue of the network device, wherein the first bank stores identifiers for network sessions for which keep-alive packets are to be sent upon termination of the next time period;
• and
• transmit, using a packet processor of the network device, the keep-alive packet for the network session, wherein the keep-alive packet is sent within the next time period.