Hi, While running an experiment in Mininet using MPTCP, MPTCP falls back to TCP after three SYN retransmissions. I have enabled MPTCP both on the host node and Mininet emulated hosts. The problem appears when multiple clients attempt to connect to the server, i.e., I have a client-server application, the servers listen on a given port and the clients connect to the servers at a certain time interval to download some file size (100KB, 30MB). A connection with a client closes after the desired file size transfer but the server continues to listen for new connections. The problem happens after some number of clients are connected and irrespective of path managers and the number of sub flows used. I have tried to enable MPTCP to debug flag and the following debug message is printed. 'mptcp_do_join_short:mpcb not found' Host evnironment: Ubuntu 16.04, Linux version 4.14.79, MPTCP (v0.94) Neither CPU nor memory seems to be part of the problem since during the test the CPU usage is less than 10% and memory usage is also negligible. I would appreciate a suggestion for a workaround for this issue.\ Thanks, Dejene Boru