Question about TCP packet.
tinguely at casselton.net
Tue Aug 30 12:31:25 GMT 2005
> found that I received 2 ack packets when sent data to embedded device.
> Does It mean one ack packet is not necessary and
> the embedded device's tcp stack is broken?
> 16:58:08.448730 192.168.168.137.1693 > 184.108.40.206.9742: P 1:22(21) ack 1 win 65535 (DF)
> 16:58:08.450458 220.127.116.11.9742 > 192.168.168.137.1693: . ack 22 win 1439 (DF)
> 16:58:08.482349 18.104.22.168.9742 > 192.168.168.137.1693: . ack 22 win 1460 (DF)
The second ack is a window update. The recieving TCP stack is telling the
sender that the data has been consumed and more space is available for
If you increase your recieve buffer size on the "22.214.171.124" host,
you will not see these updates for interactive data.
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