Ok to run phone AND data off cat5?

[Joony]

Since data uses 2 pairs, and phone uses 1 pair...Bad for data? noise from phone?

 

[cmetz]

You're not supposed to do that, please don't do it if you can avoid it. That said, it should work fine.

 

[kehi]

Joony:


I would say spring for the extra cable and split the lines up. Just my 2 cents

 

[Joony]

Alright, I thought so.

But theres nothing bad with running power over ethernet right? A measely 5 volts to power my switch at a remote location?

 

[ScottMac]

The material used to insulate UTP/Cat(anything) is not made for heat. If the remote device were to cause a short and heat the conductor excessively, you can start a fire. Even plenum cable will burn.

Power over Ethernet devices are designed and protected for handling this possibility.

Aside from the potential safety issues, 5VDC will not travel well over 26 guage wire. DC current suffers much loss compared to AC. Power over Etherent devices are usually at least 12VDC, and more likely -48VDC. The extra "pressure" from the higher voltage helps the current make the trip through the small guage wires.

FWIW

Scott

 

[cmetz]

Joony, rolling your own power over Ethernet should be left for the EEs in the room. If you don't know what you're doing, don't try it. If you do know what you're doing, you should be okay.

IEEE 802.3af PoE is 350mA max @ 48V over standard cat5 cable plant. There is a fairly sophisticated level of protection against overcurrent (short et al.) conditions, including a PoE link sense that must be done in order to "negotiate" sending power down the port (that is to say, it is not powered by default, you have to do something to trigger the PoE injector to send). All this is there for good reasons, so if you're rolling your own you should think carefully about whether you should roll your own without the same protections.

The 3Com NetJack switches are cheap in-wall switches with pass-through ports that accept PoE, and you can use an outboard injector on the other side of a cable. This will allow you to have a remote PoE switch on a budget. I'd strongly urge you to use an off-the-shelf solution like this.

 

[Joony]

Hmm, there are alot of people doing these out there

http://www.nycwireless.net/poe/

http://kawasaki.kz/wireless/poe.htm

http://www.wireless.org.au/~jhecker/poe/

 

[QTPie]

wow, that's interesting. thanks for your info JOONY

 

yea, even linksys makes POE routers now. I still think power and data should be left seperate though.

just like cmet says, imagine, low voltage, DC, over a small circumference wire... Sounds like your asking for trouble.

P.S. How do you insert those cool simelys? I wanted to put a fire one but I have no idea how to insert them.

 

[JackMDS]

POE = DC

DC= Direct Current

Direct Current = Good . No Noisy Noisy, only warmy warmy

Phone line = Big Spikes of A.C.

A.C = Alternate Current.

Alternate Current = Noisy Noisy.

Noisy, Noisy sends Network traffic to an Alternate Dimension in the Twilight Zone.