Planet Technology Internet Telephony PBX System IPX-1900 - Manual (Page 49)

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L2TP Pass Through
L2TP (The Layer 2 Tunnel Protocol) is an emerging Internet Engineering
Task Force (IETF) standard that combines the best features of two
existing tunneling protocols: Cisco's Layer 2 Forwarding (L2F) and
Microsoft's Point-to-Point Tunneling Protocol (PPTP). L2TP is an
extension to the Point-to-Point Protocol (PPP), which is an important
component for VPNs. VPNs allow users and telecommuters to connect to
their corporate intranets or extranets. Enable/Disable this function.
SIP ALG
SIP, the Session Initiation Protocol, is a signaling protocol for Internet
conferencing, telephony, presence, events notification and instant
messaging. Enable/Disable this protocol verification.
DMZ
In computer networks, a DMZ (Demilitarized Zone) is a computer host or
small network inserted as a "neutral zone" between a company's private
network and the outside public network. It prevents outside users from
getting direct access to a server that has company dIP-PBX. Think of DMZ
as the front yard of your house. It belongs to you and you may put some
things there, but you would put anything valuable inside the house where
it can be properly secured. Setting up a DMZ is very easy. If you have
multiple computer s, you can choose to simply place one of the computers
between the Internet connection and the firewall.
DMZ IP LAN
If you have a computer that cannot run Internet applications properly from
behind the device, then you can allow the computer to have unrestricted
Internet access. Enter the IP address of that computer as a DMZ host with
unrestricted Internet access. Adding a client to the DMZ may expose that
computer to a variety of security risks; so only use this option as a last
resort.
Table 4-6. NAT description
¾ Virtual Server Mapping
The device can be configured as a virtual server so that remote users accessing services such as Web
or FTP services via the public (WAN) IP address can be automatically redirected to local servers in the
LAN network. Depending on the requested service (TCP/UDP port number), the device redirects the
external service request to the appropriate server within the LAN network. You will only need to input
the LAN IP address of the computer running the service and enable it.
A Virtual Server is defined as a service port, and all requests to this port will be redirected to the
computer specified by the server IP.