ZyXEL Communications P-202H Plus v2, Поддержка заметок

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P-202H Plus v2 Support Notes
IPSec Related FAQ
IPSec FAQ
VPN Overview
1. What is VPN?
A VPN gives users a secure link to access corporate network over the Internet or
other public or private networks without the expense of lease lines. A secure
VPN is a combination of tunneling, encryption, authentication, access control and
auditing technologies/services used to transport traffic over the Internet or any
insecure network that uses the TCP/IP protocol suite for communication.
2. Why do I need VPN?
There are some reasons to use a VPN. The most common reasons are because
of security and cost.
Security
1). Authentication
With authentication, VPN receiver can verify the source of packets and
guarantee the data integrity.
2). Encryption
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.
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