File content as of revision 160:6a1d1d368f80:

Names
=====
ISN     == Initial Sequence Number
SEQ num == Sequence Number is the sequence of the first byte of the sent data packet - unless a SYN in which case it is the ISN
ACK num == Acknowledge Number is the next sequence number that the sender of the ACK is expecting
TCB     == Transmission Control Block
RTO     == Retransmission Time Out

Only received packets with a sequence of 1 (position == 0) is handled; any others are ignored. This works because we only handle the first line.

From RFC793
Reset Processing

  In all states except SYN-SENT, all reset (RST) segments are validated
  by checking their SEQ-fields.  A reset is valid if its sequence number
  is in the window.  In the SYN-SENT state (a RST received in response
  to an initial SYN), the RST is acceptable if the ACK field
  acknowledges the SYN.

  The receiver of a RST first validates it, then changes state.  If the
  receiver was in the LISTEN state, it ignores it.  If the receiver was
  in SYN-RECEIVED state and had previously been in the LISTEN state,
  then the receiver returns to the LISTEN state, otherwise the receiver
  aborts the connection and goes to the CLOSED state.  If the receiver
  was in any other state, it aborts the connection and advises the user
  and goes to the CLOSED state.
  
Retransmission Timer – To retransmit lost segments, TCP uses retransmission timeout (RTO).
When TCP sends a segment the timer starts and stops when the acknowledgment is received.
If the timer expires timeout occurs and the segment is retransmitted.
The timer 'SendsBeingAcked' is reset whenever:
    tcprecv - a packet is received where the ack counter has advanced;
    tcpsend - the ack count received is the same as the seq count sent
    tcpsend - resent the last unacked packet