Lucent Technologies 6000 User Manual
MAX 6000/3000 Network Configuration Guide
11-1
11
Setting Up Virtual Private Networks
Introduction to Virtual Private Networks
Virtual Private Networks (VPNs) provide low-cost remote access to private LANs via the
Internet. The tunnel to the private corporate network can be from an ISP, enabling mobile
clients to dial in to a corporate network, or it can provide a low-cost Internet connection
between two corporate networks. Lucent currently supports three VPN schemes: Ascend
Tunnel Management Protocol (ATMP), Point-to-Point Tunneling Protocol (PPTP) and Layer 2
Tunneling Protocol (L2TP).
Internet. The tunnel to the private corporate network can be from an ISP, enabling mobile
clients to dial in to a corporate network, or it can provide a low-cost Internet connection
between two corporate networks. Lucent currently supports three VPN schemes: Ascend
Tunnel Management Protocol (ATMP), Point-to-Point Tunneling Protocol (PPTP) and Layer 2
Tunneling Protocol (L2TP).
An ATMP session can occur only between two Lucent units and must use UDP/IP. The MAX
encapsulates all packets passing through the tunnel in standard Generic Routing Encapsulation
(GRE) as described in RFC 1701. ATMP creates and tears down a cross-Internet tunnel
between the two Lucent units. In effect, the tunnel collapses the Internet cloud and provides
what looks like direct access to a home network. The tunnels do not support bridging. All
packets must be routed with IP or IPX.
encapsulates all packets passing through the tunnel in standard Generic Routing Encapsulation
(GRE) as described in RFC 1701. ATMP creates and tears down a cross-Internet tunnel
between the two Lucent units. In effect, the tunnel collapses the Internet cloud and provides
what looks like direct access to a home network. The tunnels do not support bridging. All
packets must be routed with IP or IPX.
The Microsoft Corporation developed Point-to-Point Tunneling Protocol (PPTP) to enable
Windows 95 and Windows NT Workstation users to dial into a local ISP to connect to a private
corporate network across the Internet.
Windows 95 and Windows NT Workstation users to dial into a local ISP to connect to a private
corporate network across the Internet.
Version 8 of the Internet Engineering Task Force (IETF) draft titled Layer Two Tunneling
Protocol “L2TP,” dated November, 1997, specifies the Layer 2 Tunneling Protocol (L2TP).
L2TP enables you to connect to a private network by dialing into a local MAX, which creates
and maintains an L2TP tunnel between itself and the private network.
Protocol “L2TP,” dated November, 1997, specifies the Layer 2 Tunneling Protocol (L2TP).
L2TP enables you to connect to a private network by dialing into a local MAX, which creates
and maintains an L2TP tunnel between itself and the private network.
Note:
Any MAX unit supporting PPTP or L2TP does not display a terminal-server prompt to
dial-in users, because all dial-in calls are immediately transferred to PPTP or L2TP servers.