Inline POE and Linksys Routers (WRT54G)

[seagull]

After contacting a number of manufacturers, I am still at a total loss for an accurate answer with regards to Power over Ethernet and Linksys Routers (WRT54G)

Here is the situation:
I am running a simple, home-based wireless LAN with the key component being a Linksys WRT54G wireless 802.11g router (external power is 12V DC, 1.0A) (http://www.linksys.com/products/product.asp?grid=33&scid=35&prid=601).

The issue is I now need to move the router and I don't have a power source next to where the router needs to go. As such, I was going to use another Linksys product called a WAPPOE (http://www.linksys.com/products/product.asp?grid=33&scid=38&prid=582) and run power across the Ethernet cable. The problems are, according to Linksys, the WAPPOE can
(a) only handle 5V of current across the Ethernet cable, but the router requires 12V, and
(b) Linksys is not even sure if the WAPPOE will even work with CAT6 cable (which I just deployed in the house).
As such, they default to telling me it won't work.

I have researched a few manufacturers of POE equipment (PowerDsine, SeaCom, SonicWall, etc...). I am at a loss as to what CATEGORY of POE device I even need. For example, I don't even know if I need
(A) a SPLITTER (for an external 12V application) (e.g. PowerDsine PD-401/12 (http://www.powerdsine.com/Products/Midspan/Splitters/ActiveSplitter.asp)) or
(B) a single-port midspan (e.g. PowerDsine 6001 (http://www.powerdsine.com/Products/Midspan/PD_6001.asp))

SO MY QUESTIONS ARE
(1) Which of these products will solve my problem? (splitter, POE midspan, other)?
(2) Depending on the answer to (1), will it provide power across my Ethernet cable to a Linksys WRT54G (12Volt, 1A) (note: it's traveling less than 100ft).?
(3) If so, will this work across CAT-6 cable (which I have deployed throughout the network)?

Thanks in advance to anyone who can answer this.:confused:

[bobpaul]

This is a very long post. Sorry. I tend to err on the side of detail

I'm not even going to look at those products you have listed, that's too much work for me at the moment and I don't feel I would know any more information than you (if their product description says 12v and 1A or greater than 1A, you're fine)

What I will say is that anything that works with Cat 5 will work with Cat 6. The only difference between Cat 5 and 6 is that 6 has more twists per foot (ie, inside the cable are pairs of wires, orange and orange-stripe, green and green-stripe, etc. The pairs are twisted together to prevent cross talk. In cat 6 they are twisted more frequently to protect against crosstalk even better.) The guage and everything else is the same. I don't know why Linksys would say it doesn't work with Cat 6, that doesn't make sense.

Something else I will note is that instead of spending all that money on a PoE product just to power your router, you may as well do it yourself. I'm assuming you installed the Cat 6 in your house on your own.

First, a standard disclaimer.
WARNING: PROCEEDING PAST THIS POINT COULD DAMAGE YOUR EQUIPMENT. BE SURE YOU KNOW WHAT YOU ARE DOING. RESEARCH BEYOND WHAT IS WRITTEN IN THIS POST MAY BE REQUIRED TO SUCCESSFULY COMPLETE THIS PROJECT. DAMAGED EQUIPMENT IS NOONE'S FAULT BUT YOUR OWN.

What you need

Knife or Scissors
Wire Stripper
Electrical Tape
Cat 5 or Cat 6 cabling
RJ45 Connectors
RJ45 Crimp Tool (Crimpless connectors should work, but not prefered)
Solder & Soldering Iron (Optional)
LineJack & Line Plug (Optional if you don't want to cut your existing PowerCord)
Electrical "Multitester" to ensure polarity (highly recommended)



Take a peak at this:
http://www.freenet-antennas.com/~freenet-/oscommerce-2.2ms2/catalog/product_info.php?products_id=138

For $160 you can buy a weatherproof enclosure for your WRT. That's not what's important. What's important is that block diagram. Notice how they just plugged the router's power supply directly into the Cat5 cable? That's what we're going to do.

Inside the Cat 5/6 cable are 8 wires (4 pairs as discussed above). Only 2 of the pairs are used. Gigabit networking uses all 4 pairs, and this is why we can't use PoE with gigabit.

Take a look here to familiarize yourself with ethernet wiring standards, especially the pin locations:
http://www.ertyu.org/~steven_nikkel/ethernetcables.html

You'll notice it labels which pins are unused. Normally these are grounded. We will use them for power instead. That means you should not hook the wires of your PoE cable to pins 4, 5, 7, & 8 on either ends. (Green and Brown pairs, normally)

Make a cable using either the T568A or T568B standard on both ends but leave the blue and brown pairs hanging out of the connector. Strip the blue and brown pairs and twist blue and white/blue together and brown and white/brown together on both ends. Cut your Linksys router's power connector and twist 1 of the wires in the power connector to the brown wires and 1 to the blue wires. Do to the same with the connector end. There will probably be 1 bare copper wire and one red or black wire which will help you keep track. Just do the same on both ends (ie, if you hook the red wire to the blue on one end, hook it to the blue on the other end.) BE CAREFUL NOT TO REVERSE THE POLARITY AS THAT COULD DAMAGE YOUR ROUTER.

If you don't want to cut your power adapter's cable, goto RadioShack and buy a plug and a jack that match yours. If you look on your power adapter you should see a graphic like this [ + ----o )---- - ]. This means that the Tip (inside the plug) should be positive and the outside should be negative. Use the multitester to verify your connections.

The reason we twist the brown and blue pairs together is to turn 4 wires into 2 wires. This will lessen the resistance factor and allow the cable to carry more amperage. Note that longer distance = higher resistance = lower amperage as well. Freenet sells their cable at 20 m (65 ft) so it should work for that distance. Otherwise you won't likely harm the router (by giving it less amperage) but you might stress the power adapter (by making it do more work). I'm going to venture to say that 100 feet should be alright, but I also haven't bothered to calculate the maximum power. I would personally feel safe at 100 feet, but I would also be ready to buy a new power adapter.

When you're done, cover all exposed copper with electrical tape. If you soldered your twisted wires, kudos to you. If not, they may pull out over time, but should be fine at least for temporary.

See the bad paintbrush diagram below:
http://i4.photobucket.com/albums/y106/bobpaul/DiyPoweroverEthernetcable.gif

You might also be able to get freenet antenna's to sell you just the PoE cable (an ethernet cable with jacks already on the ends.) Call or e-mail and find out if their willing.

I've seen some Cat 5/Cat 6 cable that uses colors other than orange, green, brown and blue. If this is the case, just substitute for what colors you do have. The important thing is that you keep pairs together (if you substitute Pink for Orange, substitute White-Pink for White-Orange) and that you do the same substitution on both ends.

[Edit]
As a safety note, Category 5 cable uses 24 AWG. If you look you'll see that the maximum current on a 24 guage wire is 920mA (http://www.powerstream.com/Wire_Size.htm). Since this is not quite 1A, we use two wires for each of our conductors, the two brown and the two green, to provide us with 1.8A of maximum current. 1A is plety safe in this configuration.

I recently did a project that needed 5V at something like 8A. We can't do that directly, but using a pair of voltage converters I got from TI (go free samples!) I ended up running 48V over the cat 5 but placing a 5-48V converter at one end and a 48-5V converter at the other end. 5V*8A=40W. 40W/48V=830mA. I could have safetly done this with just one pair (barely), but I still used the green and brown paired as shown in the picture.