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A Linksys WRE54G extender allows one to expand their wireless internet. They are available for purchase on Amazon and eBay. Walmart and Target often carry Linksys extenders as well.
nat
Packets sent through Linksys integrated router using NAT can be described in two ways. First, packets have to be translated if they are sent to another LAN, and secondly, packets sent to hosts within the same LAN need no translation.
Linksys makes a few range extenders for G routers costing about sixty to eighty dollars.
You can buy a wireless Linksys router for as little as $35 right now. If you don't need wireless you may be able to save a few dollars, but having it available can be useful. If you do get a wireless router, be sure it is certified for "N" and features WPA security. Many may only support WEP, which is not as secure.
In order to find out whether the Linksys E3000 comes with any built-in security features, please consult the owner's manual that came with your unit. Since it is a router, it is mostly likely security features built-in or else there will be too many problems that can arise.
The Linksys RT31P2 phone adapter is manufactured by the Cisco company, and as such is officially available from any approved and authorised Cisco reseller.
The wireless connection is good
The router supports encryption and authentication
The router supports 802.11b, 802.11g, and 802.11n devices By Garga
Amazon have a wide range of Linksys routers available on their website at various prices and with excellent information and customer reviews to help you make up your mind.