Does this series of interfaces require that you get audio in and out of the computer via cat5e cable? Or???  i am a bit confused about that. It says usb and thunderbolt as well so I guess I just don't get the whole ethernet thing.  forgive my ignorance

I have the Ultralite AVB. It uses USB for audio.
The ethernet (cat5) is just for linking audio interfaces - Windows doesn't have a driver for running "AVB audio".
 
Someone please correct me if this is wrong

John is correct, there currently isn't an "AVB via Ethernet" driver for Windows.
 
The Ultralite AVB is USB only.
The larger AVB audio interfaces have both USB and Thunderbolt.
 
Note: To make use of Thunderbolt, you'll need to be running one of the latest Z170x or X99p motherboards that provides Thunderbolt-3 via USB-C port... and you have to be running Win10.
You'll also need a Thunderbolt-3 (USB-C) to Thunderbolt adapter (which is ~$84).

thank you guys.  I am considering the ultralite, one of the 828s, or the 1248.   I understand that windows thunderbolt drivers aren't available. Or they are in their infancy.  
 I am considering the 1248 because of the 12 analog inputs.  I am assuming it would deliver great latency.
I am running windows 10 now.  My board is supposedly TB ready but I don't believe it is one of the ones you mentioned.

Microsoft doesn't support "PCIe via Thunderbolt" with Thunderbolt-2 controllers.
 
If you want PCIe level performance from Thunderbolt (under Windows), there's no way around the following:

• Z170x or X99p motherboard that provides Thunderbolt-3 via USB-C port
• Windows 10
• Thunderbolt-3 to Thunderbolt adapter
• Audio interface drivers that support "PCIe via Thunderbolt"

MOTU has public beta drivers available (now) that support "PCIe via Thunderbolt".
 
Note:
Prior to Microsoft's very recent support of "PCIe via Thunderbolt"... literally all Thunderbolt audio interfaces running under Windows were using "Firewire protocol via Thunderbolt"

Jim Roseberry
Microsoft doesn't support "PCIe via Thunderbolt" with Thunderbolt-2 controllers.
 
If you want PCIe level performance from Thunderbolt (under Windows), there's no way around the following:

• Z170x or X99p motherboard that provides Thunderbolt-3 via USB-C port
• Windows 10
• Thunderbolt-3 to Thunderbolt adapter
• Audio interface drivers that support "PCIe via Thunderbolt"

MOTU has public beta drivers available (now) that support "PCIe via Thunderbolt".
 
Note:
Prior to Microsoft's very recent support of "PCIe via Thunderbolt"... literally all Thunderbolt audio interfaces running under Windows were using "Firewire protocol via Thunderbolt"

Those motherboards are pricy.   but the usb from the motu stuff is pretty damn good from all reports.  

HighAndDry
 
Those motherboards are pricy.   but the usb from the motu stuff is pretty damn good from all reports.  

Yes they are...
They're the "latest/greatest" motherboards with the latest features... and you always pay a premium buying at the front of the curve.
 
MOTU AVB USB performance is exceptionally good.

Thanks Jim.