how does the usbnet works

the usb system didnot have the interrupt resource , so every translation should issue from the host device(PC)。But when we use the usbnet, the device and the pc ca开发者_运维百科n be used as a computer via the ethernet.

I am confusing about if the device ping the host at first , how does the host know this translation?

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it seems the host (the computer on which the ethernet/usb adapter is plugged) simply polls the adapter at regular interval to check for the arrival of some data.

an usb device is like a "slave" to the host computer. so when the device receives some data from the network, it buffers them. regularly, the host computer asks the device if he has received some data, the device can then transmit the buffered data to the host.

the host is asking the device very often (hundreds of time per second).