I found this on a well known av site so maybe my certified cable will suffice.
HDMI " with Ethernet" showed up around 2009 , it carried that data between pins 14, and 19 , along with ARC and was limited to 100mbps , this at a time when every new piece of gear was coming with gigabit (1000 mbps) ports , so it never got implemented on any piece of commercial equipment.
However , it now uses the bandwidth that was available for " internet" for ARC and more importantly eARC which allows lossless audio on the return channel.
All certified cables bought today should have the " with ethernet" channel , with older cables this was not always the case and the wires between pins 14 and 19 were not a shielded twisted pair on non " with ethernet" cables meaning they couldnt handle the bandwidth