Networking / Beginners

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Bridging Other Networks to Your Wireless LAN

Your wireless LAN is your home's backbone over which a lot of traffic can pass, but it's likely not the only network in your house. You may have other wired networks that you wish to interconnect with your home's wireless LAN. Among these networks are

• HomePlug (www.homeplug.org): This is a standardized approach to communicating over a home's electrical wiring.
• HPNA (Home Phone Networking Alliance, www.homepna.org): This is a standardized approach to communicating over a home's telephone wiring.
• MoCA (Multimedia over Coax Alliance, www.mocalliance.org): This is a standardized approach to communicating over a home's coaxial wiring.
• X10: This is a standardized approach to communicating over a home's electrical wiring for short data burst for home automation applications.
• Ethernet: This is a standardized approach to communicating over CAT-5e four-pair wiring.

Interfacing with these networks is simple:

• Use the network technologies' Wi-Fi adapter. The networks may have an 802.11-integrated adapter unit as part of their offerings. A standard access point interfaces 802.11 wireless with Ethernet. For the other technologies, such as HomePlug for HPNA, you would use special units designed to have a co-presence on both networks. The Siemens SpeedStream 2521 Powerline 802.11b Wireless Access Point, for instance, is an 802.11-outfitted "wall wart" access point module with HomePlug-compliant electrical prongs. Plug this unit into an electrical outlet, and your access point communicates with your HomePlug router over the electrical lines in your home - bridging between the two networks.
  Warning When these 802.11 integrated products came out from the various manufacturers, there was a lot of buzz, but not a corresponding spike in sales. That's because access points are so cheap and so fully functional that you are better off getting a simple Ethernet jack from HomePlug, HPNA, or other technology and plugging your access point into that. More recently, with the emergence of longer-range 802.11 in the home, like the Belkin Pre-N wireless devices, the need for the in-home wiring has been done away with altogether in many instances. As a result, most of these alternative devices are still just 802.11b-compliant and do not support advanced features like WPA. We can't say we really recommend them highly at this point.
• Use your router. If the networks do not support a direct bridge - or you do not want to use their direct interface for the reasons cited in the previous Warning - you can bridge via your router. Your access point is connected to your router, and your router routes your data to locations on the networks.

The decision of which approach to use, we think, is pretty clear - follow the paradigm of stereo gear, where "separates" win out over "all-in-one" gear. You are better off with a stand-alone access point and a stand-alone transport layer than mixing the two and compromising your future intentions. This being said, choose the "Use your router" option as your main way to interface between the networks.

If you have purchased a bundled package for one of the alternative network communications systems, have no fear - it's not that the adapter approach won't work; you're just more likely to have to make compromises in the way you approach your whole LAN, such as the WPA limitation noted earlier.