L2TP

The BRAS does the encapsulation autodetection, handles the PPP to L2TP translation, and passes L2TP to AAISP.

Archive 2010-02-01 Farnz 2010

Your MSAN port does the autodetection, removes the ATM cell framing, adds Ethernet framing if you're doing PPPoA, and sends the resulting PPPoE frame which can be oversized - allowing a full 1500 byte MTU to the BRAS, which then does PPP to L2TP and passing data to AAISP.

Archive 2010-02-01 Farnz 2010

The BRAS does the encapsulation autodetection, handles the PPP to L2TP translation, and passes L2TP to AAISP.

On PPPoA, PPPoE, ATM and ADSL Farnz 2010

Your MSAN port does the autodetection, removes the ATM cell framing, adds Ethernet framing if you're doing PPPoA, and sends the resulting PPPoE frame which can be oversized - allowing a full 1500 byte MTU to the BRAS, which then does PPP to L2TP and passing data to AAISP.

On PPPoA, PPPoE, ATM and ADSL Farnz 2010

The BRV324 advertises support for 70 IPSec and 10 PPTP VPN connections, or 100 pass-through sessions with IPSec, PPTP and L2TP.

TRENDnet BRV324: Inexpensive, good performance 2010

Now think about this in reverse, if your connection goes through a L2TP tunnel and then becomes Layer 3 as it starts presenting itself to Wikipedia your location cannot actually be known at all.

Archive 2007-08-01 2007

What if that router decided to terminate the connection via L2TP tunnelling?

Archive 2007-08-01 2007

Note: L2TP must first be enabled in the Main CVC on the device using the command line.

Setting L2TP Keywords for the VPN Group 2001

An individual L2TP client appears to the device as a LAC that tunnels a single PPP session.

L2TP Overview 2001

Combined IPSec client tunnels, LAN-to-LAN tunnels, L2TP tunnels, and

VPN 5000 Features 2001