Software Features; Nat Features - Asus iPBX30 User Manual

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Chapter 2

2.3 Software Features

iPBX30 provides Network Address Translation (NAT) to share

a single high-speed Internet connection and to save the cost of

multiple connections required for the hosts on the LAN segments

connected to it. This feature conceals network address and

prevents them from becoming public. It maps unregistered IP

address of hosts connected to the LAN with valid ones for Internet

access. iPBX30 also provides reverse NAT capability, which

enables users to host various services such as e-mail servers, web

servers, etc. The NAT rules drive the translation mechanism. The

following types of NAT are supported by iPBX30.

• NAPT (Network Address and Port Translation)

Also called IP Masquerading or ENAT (Enhanced NAT). Maps

many internal hosts to only one globally valid IP address. The

mapping usually contains a pool of network ports to be used for

translation. Every packet is translated with the globally valid IP

address; the port number is translated with a free pool from the

pool of network ports.

• Reverse NAPT

Also called inbound mapping, port mapping,or virtual server.

Any packet coming to the router can be relayed to an internal

host based on the protocol, port number and/or IP Address

specified in the rule. This is useful when multiple services are

hosted on different internal hosts.

iPBX30 User Manual

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