Vpn - Yealink SIP-T2 Series Administrator's Manual

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860 IP Phones
Enter the desired value in the Pri.DNS and Sec.DNS field respectively.
4.
Press the Save soft key to accept the change.
5.
A dialog box pops up to prompt that the settings will take effect after a reboot.
Click OK to reboot the phone.
6.

VPN

VPN (Virtual Private Network) is a secured private network connection built on top of public
telecommunication infrastructure, such as the Internet. It has become more prevalent due to
benefits of scalability, reliability, convenience and security. VPN provides remote offices or
individual users with secure access to their organization's network.
Types of VPN Access
There are two types of VPN access: remote-access VPN (connecting an individual device to a
network) and site-to-site VPN (connecting two networks together). Remote-access VPN allows
employees to access their company's intranet from home or outside the office, and site-to-site
VPN allows employees in geographically separated offices to share one cohesive virtual network.
VPN can be also classified by the protocols used to tunnel the traffic. It provides security
through tunneling protocols: IPSec, SSL, L2TP and PPTP.
VPN Technology
IP phones support SSL VPN, which provides remote-access VPN capabilities through SSL.
OpenVPN is a full featured SSL VPN software solution that creates secure connections in remote
access facilities, designed to work with the TUN/TAP virtual network interface. TUN and TAP are
virtual network kernel devices. TAP simulates a link layer device and provides a virtual
point-to-point connection, while TUN simulates a network layer device and provides a virtual
network segment.
IP phones use OpenVPN to achieve VPN feature. To prevent disclosure of private information,
tunnel endpoints must authenticate each other before secure VPN tunnel is established. After
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