How does "Power-Over-Ethernet" work?

As we all know, 100BT uses 2 pairs, one for Tx, one for Rx.

One of the reason they were able to squeeze 1GB on Ethernet was by using all 8 conductors.

So, if I have a Gigabit LAN with VoIP phones, how is the power delivered to the SIP phones if all conductors are used already?

TIA,

-Ramon

Reply to
Ramon F Herrera
Loading thread data ...

The standard specifies several modes, one of which is shared signal and power, but I haven't seen anybody run in this mode. All I've seen is power over the unused pins after the two ends negotiate what mode they'll be in.

Most often, you get 10/100 and PoE connections. Gigabit has to be handled seperately out to the desktop.

Reply to
Doug McIntyre

Evening Ramon;

More info than you probably wanted to know:

formatting link
Jeff

Reply to
Jeff Little

This box does POE on 1000base-T according to 802.3af:

formatting link

Reply to
R-Guy

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.