Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > VOIP > How does "Power-Over-Ethernet" work?

Reply
Thread Tools

How does "Power-Over-Ethernet" work?

 
 
Ramon F Herrera
Guest
Posts: n/a
 
      11-18-2005
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 With Quote
 
 
 
 
Doug McIntyre
Guest
Posts: n/a
 
      11-18-2005
"Ramon F Herrera" <(E-Mail Removed)> 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.




 
Reply With Quote
 
 
 
 
R-Guy
Guest
Posts: n/a
 
      11-19-2005
"Doug McIntyre" <(E-Mail Removed)> wrote in message
news:437e406f$0$30641$(E-Mail Removed) anews.com...
> "Ramon F Herrera" <(E-Mail Removed)> 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



 
Reply With Quote
 
Jeff Little
Guest
Posts: n/a
 
      11-19-2005
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" <(E-Mail Removed)>
wrote:

>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 With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
.NET 2.0 ASPx Page does not load, but HTM does prabhupr@hotmail.com ASP .Net 1 02-08-2006 12:57 PM
Button OnClick does not fire on first postback, but does on second Janet Collins ASP .Net 0 01-13-2006 10:08 PM
Does the 2.0 Framework come out when Visual Studio .NET 2005 does? needin4mation@gmail.com ASP .Net 3 10-07-2005 12:55 AM
CS0234 Global does not exist ... but it genuinely does Bill Johnson ASP .Net 0 07-08-2005 06:34 PM
Does no one else think microsoft does a poor job? =?Utf-8?B?SmVyZW15IEx1bmRncmVu?= Wireless Networking 2 11-20-2004 12:17 AM



Advertisments