Yealink SIP-T48G Administrator's Manual page 435

4. Press the Save soft key to accept the change.
The IP phone reboots automatically to make settings effective after a period of
time.
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. 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 .
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 VPN feature is configured
properly on the IP phone, the IP phone acts as a VPN client and uses the certificates to
authenticate the VPN server.
To use VPN, the compressed package of VPN-related files should be uploaded to the IP
phone in advance. The file format of the compressed package must be *.tar. The
related VPN files are: certificates (ca.crt and client.crt), key (client.key) and the
configuration file (vpn.cnf) of the VPN client. For more information on how to package a
OpenVPN Feature on Yealink IP Phones
TAR file, refer to
http://www.yealink.com/DocumentDownload.aspx?CateId=142&flag=142.
Procedure
VPN can be configured using the configuration files or locally.
Configuration File <y0000000000xx>.cfg
Configuring Advanced Features
, available online:
Configure VPN feature and upload a
TAR file to the IP phone.
Parameters:
network.vpn_enable
openvpn.url
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