Wireshark · Wireshark-users: [Wireshark-users] position acquisition

[Michel NoSpam <michel.tempo@xxxxxxxx>]

Hello,

I would to know a which level Wireshark samples the IP packets.
I use a mobile phone as a modem (DUN). A flow control permits to adjust the data flow from the PC to the modem.

We have a downlink and a uplink data flow.

Because of this flow control, we can see that the downlink TCP data are not acknowledge immediately.

I would like to know where wireshark samples the data?

When the data leave the ipstack or when the data leave the PC?

(stack ip -> USB -> modem) 

Thanks a lot. 
Michel