| Author |
Message |
Ramon F Herrera
Guest
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 Posted:
Sat Nov 19, 2005 1:04 am Post subject:
How does "Power-Over-Ethernet" work? |
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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 |
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Doug McIntyre
Guest
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| Posted:
Sat Nov 19, 2005 2:58 am Post subject:
Re: How does "Power-Over-Ethernet" work? |
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"Ramon F Herrera" <ramon@conexus.net> writes:
| Quote: | 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?
|
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. |
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R-Guy
Guest
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| Posted:
Sat Nov 19, 2005 6:23 am Post subject:
Re: How does "Power-Over-Ethernet" work? |
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"Doug McIntyre" <merlyn@geeks.org> wrote in message
news:437e406f$0$30641$892e0abb@auth.newsreader.octanews.com...
| Quote: | "Ramon F Herrera" <ramon@conexus.net> writes:
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?
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.
This box does POE on 1000base-T according to 802.3af: |
http://www.phihong.com/assets/pdf/PSA20U.pdf |
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Jeff Little
Guest
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| Posted:
Sat Nov 19, 2005 9:20 am Post subject:
Re: How does "Power-Over-Ethernet" work? |
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Evening Ramon;
More info than you probably wanted to know:
http://www.poweroverethernet.com/
Jeff
On 18 Nov 2005 11:04:13 -0800, "Ramon F Herrera" <ramon@conexus.net>
wrote:
| Quote: | 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 |
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