USB is a popular way to connect broadband networking devices to
consumer PCs. Notable applications include cable modems and
ADSL. MCCI® offers complete driver and firmware solutions for
USB networking. Off-the-shelf eval drivers are available for
Windows platforms. When using USB networking, the Network
Interface Controller (NIC) is connected to the user's computer
using USB. If a USB-to-Ethernet bridge is being used, the USB
bus, an Ethernet NIC, and a physical Ethernet segment will all
be present. If the NIC has been integrated into the target
device (for example, as in a cable modem), the software on the
PC is the same, but the physical Ethernet segment is replaced by
a software "virtual" Ethernet segment. Figure 1 compares the USB
remote NICs to local NIC architectures. Figure 1. Remote NIC
System Diagram Figure 2 illustrates the virtual Ethernet
architecture used in USB cable modems and home networking/SOHO
routing applications. Figure 2. Virtual Ethernet Architecture
Notice that the presence of two NICs