1 | initial version |
The rule of TCP is there is no rule of TCP. There are howevers RFCs that a stack can follow or not. In the first RFC about TCP the ACK mechanism was defined as sending an ACK to every data packet received. Then in RFC 1122 it is proposed to only send an ACK every other data packet as an efficiency enhancement. So there is not one standard way to determine when to send an ACK as long as all data is being ACKed (within a reasonable timeframe).