NRF_SO_SEC_DTLS_CONN_SAVE

#define NRF_SO_SEC_DTLS_CONN_SAVE   17

#include <nrf_modem/include/nrf_socket.h>

Save DTLS connection (Write-only).

You can use this socket option to pause a session that is not frequently used by the application. Saving the session frees up memory in the modem (the modem serializes and compresses the socket). This frees up memory that can be used for other connections.

If the socket is closed, the saved DTLS data is cleaned, and the connection with the server is lost.

This option requires a DTLS v1.2 connection with renegotiation disabled.

After the socket option is successfully called, you must call NRF_SO_SEC_DTLS_CONN_LOAD before continuing to communicate on the socket.

This option can fail with different errno values:

errno	Condition	Notes
NRF_EAGAIN	Error during SSL context serialization.	The SSL context is still present
	This can happen if the modem cannot	in the socket, so data sending
	allocate enough memory or if the socket	is still possible.
	is busy sending or receiving data.
NRF_EINVAL	The socket option is not supported	Examples: DTLS handshake not
	with the current configuration.	completed; connection is not a
		DTLS 1.2 connection with
		renegotiation disabled; or
		connection does not use an AEAD
		cipher suite (AES-CCM or AES-GCM).
NRF_ENOMEM	The number of saved connections
	exceeds four.

Note

This is only supported by the following modem firmware:

• mfw_nrf9160 v1.3.5 or later
• mfw_nrf91x1
• mfw_nrf9151-ntn