[Asterisk-biz] PoE for Cisco Phones

[Paul Davidson]

> On Sun, 6 Feb 2005, Adi Linden wrote:
> 
> > > I started out with (and documented) the Cisco POE cable on the Wiki. It
> > > should work with any "dumb" POE injector. I.E. something that doesn't care
> > > about 802.3af and just injects 48dc down the line no matter what.
> >
> > This will work for a one off hobbyist type application.
> >
> > > I've since deployed the PowerDsine POE injector with their Cisco adapter
> > > cables. It understands both 802.3af as well as the CDP power protocol
> > > (with the right adapter cables).
> >
> > While this is less expensive then a Cisco powered switch, it is still way
> > too expensive if we're talking 4 phones in a building.
> 
> Certainly. It's designed for someone who already has a switching
> infrastructure deployed and needs to power a lot of phones. The other
> benefits of a centralized POE system is that it saved on UPS investments.
> 
> The problem with Cisco phones is that they do not understand 802.3af, or
> else you could just use inexpensive one-off injectors.

Actually... there is a way, although Cisco will never officially
confirm or deny- I've used it in practice, and it does work.  (I've
got about 6 phones at various locations running this way for over a
year now).

The answer is the Cisco Aironet 1200 power injector.  This is a little
brick made for their WAPs- runs  roughly $40 retail (quick froogle
search), takes the power cord/cube from the existing phone (so you
have to buy the power cube too, bringing up the total cost some more
per phone), and will drive a 7960 quite nicely. Again, Cisco would
probably have a heart attack if you told them why you were buying the
injectors, but you can use me as your R&D lab- it's a working
solution.

Pro:  Works, cost is not unreasonable

Con: Not supported, cost is still roughly $50-$80 per port,depending
on where you can find the power cubes for the phones.  Not
'intelligent' - power is always there.

-pbd