ME310G1/ME910G1/ML865G1 AT Commands Reference Guide
80617ST10991A Rev. 11 Page 686 of 1039 2021-09-23
remote host TCP connection close due to
FIN/END: normal remote disconnection decided
by the remote application
remote host TCP connection close due to RST,
all other cases in which the socket is aborted
without indication from peer (for instance
because peer doesn't send ack after maximum
number of retransmissions/peer is no more
alive). All these cases include all the "FATAL"
errors after recv or send on the TCP socket
(named as different from EWOULDBLOCK)
socket inactivity timeout
network deactivation (PDP context deactivation
from network)
Any time socket is re-opened, last disconnection cause is reset.
Command report 0 (not available).
User closure cause (#SH) is not considered and if a user closure is
performed after remote disconnection, remote disconnection
cause remains saved and is not overwritten.
If more consecutive closure causes are received, the original
disconnection cause is saved.
(For instance: if a TCP FIN is received from remote and later a TCP
RST because we continue to send data, FIN cause is saved and not
overwritten)
Also in case of <closureType> (#SD) set to 255, if the socket has not
yet been closed by user after the escape sequence,
#SLASTCLOSURE indicates remote disconnection cause if it has
been received.
In case of UDP, cause 2 indicates abnormal (local) disconnection.
Cause 3 and 4 are still possible.
(Cause 1 is obviously never possible)