This is how long, in milliseconds, the state cookie issued during SCTP's 4-way INIT/INIT-ACK/COOKIE-ECHO/COOKIE-ACK handshake remains valid before it expires and must be regenerated, with 60000ms as the recommended value. Setting this too short can cause association setup to fail intermittently on higher-latency paths where the COOKIE-ECHO doesn't make it back before the cookie expires, forcing a retried handshake. A mobile backhaul network with variable round-trip times might need this value raised above the default to avoid sporadic association-establishment failures caused purely by cookie timeout.