XH1172 – DSE USB ADSL Modem – Installation Guide
6
LAN Mode
Bridged or routed Ethernet over ATM (RFC 1483/2864) and Classical IP over ATM (RFC
1577/2225) are supported in the LAN driver. These protocols provide LLC or VCMUX
encapsulation for carrying network inter-connect traffic over a single ATM AAL5 Virtual
Connection. LLC encapsulation is desirable when it is not practical to have a separate VC for
each carried protocol, such as with an ATM network that only supports Permanent Virtual
Circuits (PVCs). The provided NDIS 5 drivers automatically establish a “connection-less”
calls using the defined PVC, and encapsulate Ethernet bridged frames.
WAN Mode
RFC-2364, PPP over ATM, is supported in the WAN driver. Point-to-Point Protocol provides
a method of transporting multi-protocol packets over point-to-point links. Point-to-point links
allow for services such as Link Control Protocol, Network-layer Control Protocol, and
authentication. The PPP over ATM standard brings this point-to-point services to the ATM
network where they are not inherently supported. The provided NDIS 5 drivers accept an
empty dial string on a specific “link” or PVC from Windows Dial-up networking to establish a
call, and encapsulate PPP frames. User selection of WAN or LAN encapsulation protocols
can be done manually via the provided control panel. However, auto-configuration is
supported with the provided installation wizard, so that the protocol mode is selected properly
without user intervention.
