Understanding Routers

By Wayne Maruna

    My brother-in-law insists that he has a ‘rooter’ in his computer room.  I ask him if he has someone standing there cheering as he presses the keyboard.  He says no.  I ask him if someone is cleaning out his sewer pipe from his computer room.  He says no.  So I tell him that even if he gets his kicks on Route 66, what he has on his computer desk is in fact pronounced “rrrr-OUT-er”. So what does a router do?

     If you have a computer that connects to the internet, then you have a wire coming into your house that terminates into either a DSL (digital subscriber line) modem if your internet service provider (ISP) is the phone company, or into a cable modem if your ISP is your local cable company. The modem – which stands for Modulate/Demodulate – converts the incoming signal into something your computer is designed to understand, and likewise on the outgoing side the modem converts the computer’s signal back into something the ISP can deal with.  If all you have is one computer that does not require a wireless signal, and there are no other computers, laptops, e-readers, smart phones, or smart TVs in the house, then no router is required in that scenario. All that is needed is a cable that goes straight from the modem into your computer.    But if two devices need to share the internet pathway, or if there are devices in the house that require a wireless signal, then a router is employed.

    A typical router today has five ports in the back.  One accepts the incoming cable from the modem. This is considered the WAN port, which stands for Wide Area Network.  This is your portal to the internet through the modem.  The other four ports are for your LAN, or Local Area Network – basically the devices within the confines of your house.  These are wired ports, which are fine if your house was pre-wired for Ethernet, with cables running to various devices which may be in differnt parts of the house.  They ports may also connect to computers in the same room, or perhaps to a networked printer within a cable’s reach to the router.  But today’s routers are also the devices that transmit and receive wireless signals to and from the various wireless devices in your home – typically laptops, tablets, e-readers, smart phones, and smart TVs or Blu-Ray players.

    Routers are taken for granted until they don’t work, but they are amazing devices when you think about it.  They keep track of which devices are requesting data from the ISP or sending outgoing data, and they route requested data back to only the appropriate device.  They allow multiple devices, wired and wireless, to share that one pathway to the internet at the same time without getting everything jumbled up.  They also allow traffic amongst devices on the local area network so that devices can share data, music, pictures, and video.  The router is kind of like an electronic traffic cop who is standing at a busy intersection, allowing traffic to take turns flowing in various directions, except that the router is making these decisions and passing along traffic to the correct ‘street’ tens of thousands of times per second.  That’s pretty cool for a device generally costing around fifty bucks.

    Routers work with modems and PCs because all those devices adhere to specifications set forth by a NY based organization called the Institute of Electrical and Electronic Engineers, or IEEE for short. Their standards committee has implemented a set of specifications referred to as IEEE 802.11 which provides the basis for wireless network products using the Wi-Fi brand. (“Wi-Fi” is short of Wireless Fidelity.)  Continuous improvements over the years have taken the form of amendments to the original 802.11 standard, with each amendment getting an alpha suffix.  Hence, you may see references to 802.11b, which was replaced by 802.11g, and more recently 802.11n.  The latest protocol, which is still in draft form, is called 802.11ac.  Routers are being manufactured and sold using the 802.11ac protocol even though it is still in draft form. 

Wireless routers are at heart radios which typically operate at frequencies of either 2.4 GHz or 5.0 GHz.  Single band routers typically operate at 2.4 GHz, while dual band routers can operate at either 2.4 GHz or 5.0 GHz. The 2.4 GHz frequency is shared by cordless phones, baby monitors, microwave ovens, and Bluetooth devices, and provides for only three non-overlapping channels. The 5.0 GHz frequency allows for 23 non-overlapping channels, so you are less likely to encounter interference and related dropped signals. However, your wireless devices may be limited as to which frequency they are designed to operate on.  The 802.11ac protocol utilizes only the 5.0 GHz band.  The new standard promises more bandwidth and hence faster speeds. There are also reports of improved range, which would be a welcome improvement in any home with wireless devices.

If you find yourself in the market for a new router, it would behoove you to check the websites of the key players in the market, names like Linksys, Netgear, D-Link, or Belkin, and get a feel for what they offer.  There are more than 80 brand names in the wireless router marketplace, many of them very good. I’d be looking for a dual band router offering the latest draft 802.11ac protocol. Gigabit speed is useful if you do a lot of file transfers on your LAN, but given that most local cable customers in our area are currently (as of mid-2013) paying for speeds of about 15 Mbps or less, most any currently marketed router should do a decent job handling traffic to and from the WAN (internet).