@deftypefun {int} {gnutls_dtls_set_data_mtu} (gnutls_session_t @var{session}, unsigned int @var{mtu})
@var{session}: is a @code{gnutls_session_t}  type.

@var{mtu}: The maximum unencrypted transfer unit of the session

This function will set the maximum size of the *unencrypted* records
which will be sent over a DTLS session. It is equivalent to calculating
the DTLS packet overhead with the current encryption parameters, and
calling @code{gnutls_dtls_set_mtu()}  with that value. In particular, this means
that you may need to call this function again after any negotiation or
renegotiation, in order to ensure that the MTU is still sufficient to
account for the new protocol overhead.

In most cases you only need to call @code{gnutls_dtls_set_mtu()}  with
the maximum MTU of your transport layer.

@strong{Returns:} @code{GNUTLS_E_SUCCESS}  (0) on success, or a negative error code.

@strong{Since:} 3.1
@end deftypefun