I am using TCP sockets to talk with a FTP server. All works well on a good strong connection when the speed is high. But when i trottle the connection on FTP to simulate a slow connection, the TCP connection doesn’t seem to close.
I have double checked the file on the remote server. The SHA256 checksum of the server file is the same as the client, so all data is sent over correctly.
When i receive the +KTCP_ACK: x,1 (data done sending) i send the KTCPCLOSE command. By checking KTCPSTAT before and after this command i see the socket status going from 3 (connection is up) to 4 (connection is closing). But looking at wireshark at the remote server, no TCP FIN packet is ever received. The socket stays in the closing state forever.
If i kick the client from the server i see the TCP FIN packet sent from FTP server to client, and the module responds correctly to this. Closing both the command and the passive socket and sending an +KCNX_IND
RHL769x.2.27.183100.201809071813.x7120m_3 HL7692 HL769x.2.27 x7120m FUSED 2018-09-07 18:51:19 r12879