<Tr> <Th> 320 </Th> <Td_colspan="16"> Source port </Td> <Td_colspan="16"> Destination port </Td> </Tr> <Tr> <Th> 352 </Th> <Td_colspan="32"> Sequence number </Td> </Tr> <Tr> <Th> 384 </Th> <Td_colspan="32"> Acknowledgement number </Td> </Tr> <Tr> <Th> 416 </Th> <Td_colspan="4"> Data offset </Td> <Td_colspan="4"> Reserved </Td> <Td_colspan="8"> Flags </Td> <Td_colspan="16"> Window </Td> </Tr>

Who determines how much data tcp can send before waiting for an ack