This draft provides the Yang data mode for TCP. The draft is well written and is almost ready publication. I verified the FSM state machine and all states are listed. Minor issues: None Major issues: None Nits: I reviewed the TCP Yang data model and has a question related to the FSM state machine. Would it be possible to specify the TCP Header flags SYN, FIN, ACK, RST of BFD FSM finite state machine Events and Transition. I think this would be very helpful for the TCP Yang model FSM state machine. For each state you could specify the flags set. http://tcpipguide.com/free/t_TCPOperationalOverviewandtheTCPFiniteStateMachineF-2.htm I think the TCP TCB (TCP Control Block) is missing in the Yang model. This is important for troubleshooting TCP connection state.