ZyXEL Communications PRESTIGE 128 - Manual (Page 161)

Industry Standard
Savings in Long-Distance Calls
User-Transparent
Multiple-Protocol Support
L2TP is a standard-track protocol sanctioned by the IETF (Internet
Engineering Task Force), as opposed to Microsoft’s proprietary
PPTP (Point-to-Point Tunneling Protocol). It is supported by all
the major vendors in data communications, including Microsoft.
With the help of L2TP and the Internet, long-distance calls are
replaced by local calls to the ISP. Significant savings can be
realized in the telephone cost.
L2TP is a protocol and is transparent to the existing user
applications. There is no need to invest in new software to take
advantage of L2TP.
Because L2TP tunnels exclusively at the PPP layer, protocols other
than IP can be easily supported.
®
Outsourcing of Access Service
Roaming User Support
L2TP separates the physical WAN access points from the PPP servers,
thus allowing corporations to outsource remote access service to ISPs
while maintaining the control over security. The elimination of access
hardware and maintenance personnel can mean significant savings for
corporations.
L2TP allows the POP (Point of Presence) to be located far away from the
corporate servers. This allows the roaming users to connect to the
corporate network at a reduced cost, and yet not restrict them to TCP/IP
applications.
L2TP Functionality
The two endpoints of a L2TP tunnel performs different functions. The
LNS (L2TP Network Server) terminates the PPP connection and
negotiates directly with the user's PPP protocol stack. The LAC (L2TP
Access Concentrator) relays the traffic between the LNS and the user.
ZyXEL's implementation supports both functions within a single Prestige.
*LAC = L2TP Access Concentrator **LNS = L2TP Network Server
Applications
A I & I
CCESSING NTERNET NTRANET
The Internet can only carry TCP/IP
traffic; however, by tunneling with L2TP,
non-TCP/IP data can be transported
through the Internet without the cost of
direct telephone connections. In this
application, the Prestige can serve as
either the LAC at the ISP or as the LNS at
the corporate office.
Since L2TP tunnels exclusively at the PPP
layer, the corporate server has total control
over authentication and IP address
assignment, making authentication and
firewall administration a breeze. From a cost
standpoint, the user only has to make calls to a
local ISP, saving the telephone charge of
dialing directly to the corporate server. Again,
the Prestige can be deployed both at the ISP
and at the corporate office.
If both the branch and corporate offices are using
Prestiges equipped with the L2TP feature,
can originate the tunneling to the other Prestige.
The tunnel is between the two Prestiges and is
totally transparent to the ISP, thus the user need
not make any special arrangement with the ISP.
With this unique implementation by ZyXEL,
Prestige owners can enjoy the benefits of L2TP
without waiting for the ISPs to deploy L2TP.
each
All specifications are subject to change without notice. Trademarks ore the properties of their respective owners.
Telecommuting/Roaming
Omni TA128/
Modem
MOBILE/HOME
USER
LAC
CORPORATE LAN
LNS
Prestige
Internet
Tunnel
Direct Mode Tunneling
BRANCH OFFICE CORPORATE LAN
LNS Direct Mode
Prestige
Prestige
Prestige
Internet
Tunnel
Virtual Private Network
BRANCH OFFICE
CORPORATE LAN
LNS
LAC
Prestige
Prestige
Internet
Tunnel
ISP
Prestige Series: L2TP Facts
ZyXEL
ZyXEL Communications, Inc.
4920 E. La Palma Avenue, Anaheim, CA 92807
Toll-free: 1-800-255-4101 Fax: 1-714-693-8811
E-mail: [email protected], [email protected]
Web: http://www.zyxel.com
K
ZyXEL Communications Corp.
6 Innovation Road II, Science-Based Industrial Park
Hsinchu, Taiwan 300, R.O.C.
Phone: 886-35-783942 Fax: 886-35-782439
E-mail: [email protected], support@
K
zyxel.com.tw