What's the most cost effective (reliable) way to establish a 200m ethernet link?

I've had to pull a run like you describe several times. All three ways previously mentioned will work fine, but the critical issue you mentioned is cheap.

If you're extending a network where security is a real concern, this actually rules out wireless. Adequate quality Wifi transceivers with matching outdoor rated directional antennae will run you upwards of $600 each. If you don't care about security more than running WPA2-PSK you can hack it together with two cheap $50 WAPs and a DIY Cantenna on each end.

Copper will cost you $300 to $600. Just to be safe, look for a box of Cat-5e with 24AWG solid conductors rated for moisture resistance. Run your cables straight through plug to plug rather than punch and patch at the ends. If you place a POE parent switch or power injector at one end you can place a 1port POE supported repeater in the middle. I have used this repeater several times. It's available from both Newegg and CDW for under $150 and will do fine outdoors if in a sheltered enclosure. If you don't have a sheltered location in-between an outdoor rated equivalent will cost you $250-300. Remember, only on end switch needs to transmit POE.

Fiber will cost $500 to $1000. Outdoor rated 62.5/125 cable will cost you about $300 for 200m. If you have an available WIC slot in the switches/routers at each end you can get the cards for under $150. If not, your looking at $250-350 for a switch with a fibre port on each end putting the cost around $1000 mark.

Obviously 200m is way out of range for CAT5e Ethernet. So you have three options really:

1. Have some active repeater in the middle. Maximum length for CAT5e Ethernet is 90m, so with 200m run you might have to have 2 repeaters (although if there are no bends, and you use quality cable and connectors, you might get away with 100m too.

   You can basically use any switch as a repeater. If you use PoE-powered switch, you will even not need to run a second cable for power. Of course, the switch must be rated for outside use (temperature/humidity), and it must be protected from elements, and you must have ways to access it for service if needed.

2. The second option is to use fiber optic. Of course, you'll have to have media converters on both ends (or switches with fiber-optic uplink), and laying fiber optic requires special tools/expertise. It might be more expensive than just use a repeater in the middle, but this solution will be more reliable.

3. The third option is to go wireless. Two Wi-Fi bridges with directional antennas can easily span 200m, if you have a clear line of sight. Of course, wireless has its own benefits and drawbacks. It might be cheaper than wired connection, but prone to electro-magnetic interference, has a bigger attack surface compared to a buried fiber-optic cable, etc.

maybe

• Ethernet Over Coax for $149 (pair of 2 devices "...at distances up to 4,000 feet and speeds up to 200Mbps...")

or

• Ethernet over RS485