Hacker News new | ask | show | jobs
by TacticalCoder 1364 days ago
So if I've got two computers, each with a port labelled 40 Gbps and a USB cable labelled 40 Gbps, what's the protocol I can use to copy files at close to that? FWIW I used to run PLIP back in the nineties (IP over parallel port) to share my dialup Internet connection between my desktop and "laptop", so I'm not afraid of anything.
2 comments
chx 1364 days ago
https://learn.microsoft.com/en-us/windows-hardware/design/co...

> the Ethernet over USB4 interdomain protocol, also known as USB4NET enables two USB4 PCs to establish a network connection between each other when connected using a USB4 cable, akin to connecting an ethernet cable between network cards on two PCs.

I wrote about this a month ago at https://news.ycombinator.com/item?id=32714807 it gets confusing because the USB4 protocol uses the word "routers" for hosts, devices, hubs which of course is used by Ethernet for something totally else.

link
int_19h 1364 days ago
It's rather unfortunate that you still have dig so deep to look up the auto-assigned IPs and then manually type them in Explorer.

It really ought to be as simple as file transfers from a PC to a phone - plug the cable, each side gets a prompt on whether it wants to provide access, and once you confirm, the other end shows it in the drive/device tree in Explorer.

link
TacticalCoder 1364 days ago
Ah I missed it, TYVM! It's great to see that such a feature made it into USB4 now that it's going to reach these speeds.

> I do not quite know what happens if you were to plug three hosts together via a USB4 hub. As my post above details, USB4NET properly travels over the hub but which hosts pair, I can't even guess.

Can't wait to see people trying this and reporting!

link
wmf 1364 days ago
Just don't expect to get more than ~20 Gbps due to undocumented controller bottlenecks.
link
userbinator 1364 days ago
Look up how much 10Gbit Ethernet hardware costs, and you'll find that 20Gbps is already a great value at this time.
link
wmf 1363 days ago
10G is fairly cheap but yeah, it's not as cheap as built-in Thunderbolt. (Also, attaching a 10G NIC to a laptop costs far more than the NIC.)
link