ethernet

The preferred method of connecting to a router, either for cable modem or ADSL, is via an Ethernet card [called a "NIC"] in the PC. Adding an Ethernet NIC to the PC is relatively straightforward. It is the oldest of the [high-speed, at least] networking technologies, and the most stable and straightforward. Many PCs today actually come with the Ethernet NIC installed. Please try to avoid using USB connections for networking devices. They are fine for cameras, scanners, printers. While USB may certainly work, there has been a history of flaky USB implementations in the area of power [USB devices take power off the USB line]. If you start adding multiple devices on your USB, you may be have lots of problems unless your USB implementation is the latest and greatest. USB also requires drivers on the PC. Now that is not a bad thing by itself, since Ethernet NICs require drivers also, but ethernet is a much more mature technology. And its components are much cheaper in general.

You can recognize ethernet technology by identifying the connector used (plug). This looks like a normal telephone RJ11 jack or plug, except it is a little wider, 8 pins instead of 6 pins. There will be 2 pair of wires used for ethernet, one for each of receive and transmit. Phone lines of course use only two wires (one pair), and the receive and transmit occur on the same pair. [To be technically correct, there are a lot of communication technologies that use the RJ45 jack and plug, but you are unlikely to encounter them in everyday situations. These include ISDN, ATM25, Token Ring, and DS1. All use different pairings of the 4 pair cable.] Watch out!! Gigabit Ethernet (GigE to the "in-crowd") uses all 4 pair, so you CANNOT get away with just wiring the normal two pair for ethernet 10/100baseT. Here is a discussion.

Ethernet NICs can be had for almost zero bucks, or for as much as $90 bucks. I would spend about $20 to $30 bucks and get a Netgear or a Linksys ethernet NIC. 3COM NICs tend to be more expensive, but come with a lot of diagnostic tools. Corporations like 3COM NICs a lot.

The PC stores have been making killings on what they charge for pre-built ethernet cables, and I really resent this. I will not pay $20 bucks for a 10 foot length of ethernet cable! You should make your own if you are going to be doing some serious ethernet cabling/home networking. I see some hope of the price falling - Microcenter was selling 25 foot lengths of connectorized cat 5 for $3 over the holidays. Now I can handle that.

PCs connect to hubs and switches via normal "straight-thru cables." PCs normally connect to NAT/routers with straight-thru cables as well. It gets a little confusing sometimes if you have a simple bridge modem like the original Alcatel A1000 or the STH. These connect to the PC with a straight-thru cable. So if you want to put a router behind your modem, you will need to use a crossover cable from the modem to the hub. Or use the uplink port on the hub or switch. The uplink port normally crosses the wires so you can use a straight-thru cable. Sometimes there is a switch on the uplink port to flip it from one to the other. You can almost get away without making any crossover cables. I said ....almost.

Original 10baseT ethernet runs at 10 Mb/s, half duplex [even though there is a separate pair for transmit and receive! lesson for another day.....]. When switched hubs [now there is an anomaly. I would just like to call it a switch, but you wouldn't know it is fulfilling the "hub" role, but it is really a switch] were introduced, they allowed full duplex communications. The next generation enabled 100 Mb/s ethernet. For backwards compatibility, most 100 Mb/s switched hubs (or NICs) run in auto mode to detect what speed the other end is running. "Half-duplex" means my son listens while I am speaking, and then I listen when he speaks. Very rational communications. "Full duplex" of course is the normal method of conversation - we both talk at the same time. Except in ethernet it works...! at least on switch ports. "GigE" runs at 1000 Mb/s over 4 pair of wires using special coding. It all looks like normal Ethernet at layer 2 however. There is no such thing as half duplex in GigE. It is a strict point to point technology from PC/Workstation to switch port. See this discussion for some more info on switches and hubs.

Even in these days of mindless wireless installations, ethernet continues to be the best way to implement networks. Wireless installations are still very much a security nightmare, and will remain so for a year or so.

TCP/IP STUFF

WIRELESS STUFF

PC STUFF

ADSL/CABLE MODEM STUFF