EDATA COMMUNICATIONS INC. DSL-2140W ユーザーズマニュアル

The following table describes the labels in this screen. 

Virtual Circuit 

Select the virtual circuit you wish to edit from the dropdown list. 

NAT Status 

The NAT status of the selected VC. 

Number of IPs 

Toggle whether the Virtual Circuit NAT affects a Single IP or Multiple 

IPs. 

DMZ 

Click this link to go to the DMZ screen. 

Virtual Server 

Click this link to go to the Virtual Server screen. 

NAT changes the source IP address in a packet received from a subscriber (the inside 

local address) to another (the inside global address) before forwarding the packet to the WAN 

side. When the response comes back, NAT translates the destination address (the inside 

global address) back to the inside local address before forwarding it to the original inside host. 

Note that the IP address (either local or global) of an outside host is never changed. 

The global IP addresses for the inside hosts can be either static or dynamically assigned 

by the ISP. You may also designate servers, such as a Web server and a telnet server, on your 

local network and make them accessible to the outside world. With no servers defined, your 

DSL-2140/2140W filters out all incoming inquiries, thus preventing intruders from probing your 

network. For more information on IP address translation, refer to RFC 1631, The IP Network 

Address Translator (NAT). 

Inside/outside indicates where a host is located relative to the DSL-2140/2140W. The 

computers hosts of your LAN are inside, while the Web servers on the Internet are outside. 

Global/local indicates the IP address of a host in a packet as the packet traverses a 

router. The local address refers to the IP address of a host when the packet is in the local 

network, while the global address refers to the IP address of the host when the same packet is 

traveling in the WAN side. 

Proprietary & Confidential 

Page 38 of 80 

Revision: V1.0 

 

Jan. 19 2008