What Are The Most Commonly Used Vpn Protocols; What Is Pptp; What Is L2Tp; What Is Ipsec - ZyXEL Communications P-2608HWL-D1 Support Notes

Traditionally, you have to dial to your ISP to establish a VPN connection. Thus using the ZyXEL device
as your VPN gateway, you can greatly reduce your phone bills and still enjoy secure VPN connections to
remote sites.
2).Reduces the number of access lines required
In the past, most companies pay monthly charges for two types access lines: one high-speed connection
for Internet access and one frame relay, ISDN Primary Rate Interface or T1 line to carry data. VPN may
allow a company to carry the data traffic over its Internet access lines, thus reducing the need for
additional connections for different applications.

What are the most commonly used VPN protocols?

The most commonly used VPN protocols 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.
PPTP is supported in Windows NT and Windows 98 already. For Windows 95, it needs to be upgraded
with 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 the 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 protects any protocol that runs on top of IP (for instance TCP, UDP, and ICMP). IPSec provides
cryptographic security services which enables authentication, integrity, access control, and confidentiality.
IPSec allows for the information exchanged between remote sites to be encrypted and verified. You can
create encrypted tunnels (VPNs), or just perform encryption between computers. Since you have so many
options, IPSec is truly the most extensible and complete network security solution available.
All contents copyright (c) 2005 ZyXEL Communications Corporation.
P-2608HWL Series Support Notes
註解 [user2]: Very outdated.
What about Windows 2000, XP,
Mac OS, or Unix/Linux?
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