D-Link DSL-520B User Manual

39D-Link DSL-520B ADSL2+ Modem User Manual
Section 7 - Device Info
NAT
Note: You must enable the NAT service when you congure the WAN connection at rst, the NAT item appears in the Advanced Setup
directory. In the pure bridging mode, there is no NAT service.
Overview - Setting up the NAT Function
TheDSLrouterisequippedwiththenetworkaddresstranslation(NAT)function.Withaddressmapping,severalusersinthe
local network can access the Internet via one or more public IP addresses. All the local IP addresses are assigned to the public
IP address of the router by default.
OneofthecharacteristicsofNATisthatdatafromtheInternetisnotallowedintothelocalnetworkunlessitisexplicitly
requestedbyoneofthePCsinthenetwork.MostInternetapplicationscanrunbehindtheNATrewallwithoutanyproblems.
Forexample,ifyourequestInternetpagesorsendandreceivee-mails,therequestfordatafromtheInternetcomesfromaPC
inthelocalnetwork,andsotherouterallowsthedatatopassthrough.Therouteropensonespecicportfortheapplication.
AportinthiscontextisaninternalPCaddress,viawhichthedataisexchangedbetweentheInternetandaclientonaPCin
thelocalnetwork.Communicatingviaaportissubjecttotherulesofaparticularprotocol(TCPorUDP).
IfanexternalapplicationtriestosendacalltoaPCinthelocalnetwork,therouterblocksit.Thereisnoopenportviawhich
thedatacouldenterthelocalnetwork.Someapplications,suchasgamesontheInternet,requireseverallinks(thatis,several
ports),sothatplayerscancommunicatewitheachother.Inaddition,theseapplicationsmustalsobepermittedtosendrequests
from other users on the Internet to users in the local network. These applications cannot run if NAT is activated.

D-Link DSL-520B Specifications

Data Transfer Rates

G.dmt full rate downstream	up to 8 Mbps
G.dmt full rate upstream	up to 1 Mbps
G.lite downstream	up to 1.5 Mbps
G.lite upstream	up to 512 Kbps
G.dmt.bis full rate downstream	up to 12 Mbps
G.dmt.bis full rate upstream	up to 12 Mbps
ADSL full rate downstream	up to 24 Mbps
ADSL full rate upstream	up to 1 Mbps

Interfaces

ADSL interface	RJ-11 connector
LAN interface	RJ-45 port
Ethernet	10/100BASE-T