How works TCP

[LvThin]

Hi,

I have a connection between micro controler and a PC per TCP. The controler send only and PC receives the data. With the Ethereal Programm I try to trace the data paket and see that the controler wait after every paket for an acknowledgment before it sends the next paket. is that normal?
The acknowledgment from PC (length 0) is irregulare. Often it comes afer 0.3 s. So the translation is very low. How can I change the options of PC socket. So PC more quickly ansers.

Thin

[Mathew Joy]

What you may be experience may be the effects of what is known as the "delayed acknowledgement" algorithm. This is implemented to reduce the packets sent on the wire thereby reducing the overhead of the protocol usage. If some data is on its way to the peer then the ack is piggy backed on to the segment. If there is no outgoing data for a while it sends the ack segment. Usually the timeout timer is 200ms, but it actually depends on the implemented tcp stacks. This can be adjusted by the TcpDelAckTicks registry parameter.