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Prestige 2602HWNLI-D7A Support Notes
All contents copyright (c) 2007 ZyXEL Communications Corporation.
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With encryption, VPN guarantees the confidentiality of the original user data.
Cost
1). Cut long distance phone charges
Because users typically dial the their local ISP for VPN, thus, long distance phone charge is reduced than
making a long direct connection to the remote office.
2).Reducing number of access lines
Many companies pay monthly charges for two types access lines: (1) high-speed links for their Internet
access and (2) frame relay, ISDN Primary Rate Interface or T1 lines to carry data. A VPN may allow a
company to carry the data traffic over its Internet access lines, thus reducing the need for some installed
lines.
What are most common VPN protocols?
There are currently three major tunneling protocols for VPNs. They are Point-to-Point Tunneling Protocol
(PPTP), Layer 2 Tunneling Protocol (L2TP) and Internet Protocol Security (IPSec).
What is PPTP?
PPTP is a tunneling protocol defined by the PPTP forum that allows PPP packets to be encapsulated
within Internet Protocol (IP) packets and forwarded over any IP network, including the Internet itself. The
PPTP is supported in Windows NT and Windows 98 already. For Windows 95, it needs to be upgraded
by the Dial-Up Networking 1.2 upgrade.
What is L2TP?
Layer Two Tunneling Protocol (L2TP) is an extension of the Point-to-Point Tunneling Protocol (PPTP)
used by an Internet service provider (ISP) to enable the operation of a virtual private network (VPN) over
the Internet.
What is IPSec?
IPSec is a set of IP extensions developed by IETF (Internet Engineering Task Force) to provide security
services compatible with the existing IP standard (IPv.4) and also the upcoming one (IPv.6). In addition,
IPSec can protect any protocol that runs on top of IP, for instance TCP, UDP, and ICMP. The IPSec