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Some Basics: Hub, Switch or Router
A few years ago, everyone was using hubs, which are becoming largely obsolete. The reason is that a hub basically constitutes a simple hardwired distribution channel in which everyone talks to everyone else. In principle, a hub is equivalent to a splitter, where the information is propagated from any input to any output. With relatively small networks and infrequent traffic, this is not a big problem but when it comes to multiple users accessing the network simultaneously, the consequence is collision of data.
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Switch or Router
This is where a switch comes in. A switch keeps the information of the unique MAC address of any network's participant and only routes the information according to sender and recipient. In this case, there is hardly any chance of data collision. A router is yet another step up in that it has the additional capability to perform DHCP, that is, dynamic IP negotiation. This means that, instead of relying on individual MAC (Media Access Control) addresses, it uses the Open System Interconnection (OSI) layer 3 to IP addresses that can be assigned automatic IP addresses to a given computer within the network. Data are relayed only to the recipient computer, which reduces overall traffic load and avoids the above-mentioned collision. Furthermore, if the data are not intended to reach a specific computer on the network, they are being discarded, providing a shield against random dispersion of harmful data.
Behind a Firewall
The DI-714 performs all those duties while adding a firewall to make the entire LAN side of the network completely invisible to the outside world. Just in case that someone doesn't know what a firewall is, the abridged explanation is that a firewall uses an encryption routine behind which all computers on the LAN side are hidden. The operational principle behind a firewall is stateful packet inspection and filtering. Behind this term hides a routine that will allow only data to pass through that have been requested by a PC on the LAN side. In other words, logging on to the www and requesting a webpage to be downloaded will tell the firewall that these data will be arriving and, thus, they are assigned a "requested state" and allowed to pass through the filter. On the contrary, if anyone tries to access the LAN side of the network without being invited, the data will be discarded without further notice as if there were nothing behind the firewall. Again, this is a rather simplified explanation but it'll do for here.
Wireless or Security Leak?
Combining a firewall with a wireless router appears somewhat paradox. It is true that the firewall shields against random intrusion from the web but often it is not the web but the next-door neighbor who wants to know what is going on in your network. With a wireless reach of up to 900 feet, chances are that there is someone within reach who either wants to get a free piggy-back ride on the cable access (let's call it sharing resources) or is seriously interested in some data. This is annoying enough on a wireless phone where switching the channel can throw off the (often involuntary) intruder. Similar to a wireless phone, the DI-714 offers 11 channels but for preventing intrusion of the network this is certainly not enough. The overt security leak can be effectively plugged using 64bit or 128 bit encryption, the only thing to keep in mind is that both the wireless router and the receiving wireless adapter need to be set to the same encryption key.
Back-up modem
In contrast to many other solutions, the DI-714 allows backup connection to the outside world through an external dial-up modem. This is a necessity for anyone who depends on communication for business (I don't even start to count how many times I have been cut off because of construction crews severing fiber optic cables).
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