Recently, I've been looking for the raspberry pi specs and there was something that caught my attention: "the Ethernet port of the model B is actually a built-in USB Ethernet adapter" (in Wikipedia).

I made some research on this and I found some users having issues with the Ethernet port. And in fact, even I did.

What I did was a simple stress test with iPerf, using UDP data streams, just to check CPU utilization. Surprising as it seems, there were no packet losses and CPU utilization never shot above 20 (approximately).

So, my doubt is if there is any difference between built-in USB Ethernet adapters and typical Ethernet ports, like those found in laptops/desktops.

Thanks.

There are many ways to connect a nic to the system. Laptops have used all sorts of bridge to bridge, pc card and other ways to get the data across. For the most part as long as you have the drivers, it should work OK. I suspect that the issues people have are more likely to be faulty hardware combined with totally untested software.