Comincia da WMI

codice:
Dim oWMI As Object
Dim colItems As Object
Dim objItems As Object

Set oWMI = GetObject("winmgmts:")
Set colItems = oWMI.ExecQuery("Select * FROM Win32_PerfRawData_Tcpip_NetworkInterface ")
For Each objItems In colItems
    Print "Interface: " & objItems.Name & " Rec (B/s): " & objItems.BytesReceivedPerSec & " Snd (B/s): " & objItems.BytesSentPerSec
Next