Product specifications

Efficient Networks
®
Router family
Command Line Interface Guide
Chapter 6: Connection Management
Efficient Networks
®
Page 6-51
Location
This software is installed on the workstation for the purpose of creating a tunnel to a
LAN.
Service Provider-based VPNs
Tunneling from a POP or access concentrator
VPN services can be provided to users by creating and terminating the tunnels at the
Internet Service Provider (ISP) Point of Presence (POP) on the Internet. This allows
dial-in users to place a normal call to the POP, which in turn creates a tunnel to a
Corporate site. The tunnel is not created from the dial-up device, but instead from the
device that receives that call. Before the data can get to the Internet, it is
encapsulated into the tunnel and sent to the Corporate LAN.
Types of VPNs used
All of the technologies listed above are used to create these tunnels. The ISP might
have a PVC connection to a Corporate site, or an L2TP tunnel, or even an IPSec
connection. Whatever the choice, it is transparent to the end user. The user simply
places the modem call to the ISP POP and logs onto the Corporate network.
Advantages
ISP manages the service: The end user uses traditional dial-up devices and is
connected to the Corporate network. If it does not work, then the ISP has to fix the
problem as part of the service.
ISP can offer a valuable service: The ISP can add value for the customer and sell a
managed VPN service. This can be a win / win situation for both the ISP and the end
user.
Dedicated access: This solution can work for dedicated access as well. The end user
does not know if the data connection is running over ATM or L2TP once it leaves the
customer premises. The ISP can use this in lieu of an ATM PVC.
Disadvantages
Workstation-client to LAN-server Service cost: The cost for the VPN service might be
fairly high because it is a recurring monthly cost.
No Quality of Service guarantee: Asps do not offer any guarantees for the Quality of
Service (QoS) on these accounts. QoS guarantees come with dedicated services
only.
Limited mobile access: The user cannot dial into just any ISP and expect to be
connected to the Corporate Network. There will be a limited number (and location) of
POPs that will provide the desired access.