NRF_RAI_LAST

#define NRF_RAI_LAST   2

#include <nrf_modem/include/nrf_socket.h>

Indicate that the application does not intend to send more data after the next call to nrf_send() or nrf_sendto().

This lets the modem exit connected mode more quickly after sending the data. (Enter RRC idle mode after the next output operation on this socket is complete).