asterisk users - Jan 2004 - Power Over Ethernet for *any* ethernet switch (or hub); product idea

Based on several threads I've read on this list, I assume that it would be 
handy to supply POE (power over ethernet) in an environment without having 
to purchase POE switches (assumed expensive) and abandon one's existing 
(familiar/custom/not-yet-expensed/etc.) switches/hubs.

Assume I have a non-POE switch with 24 RJ-45 (ethernet) ports.  I design a 
1U box that can be mounted just above/below the non-POE switch, call it a 
"POEI" (POE inserter).  This box has 48 RJ-45 ports, 24
"inputs" and 24
"outputs".  The end user removes all the ethernet cables connected to
the
existing switch and moves them to the "outputs" of the POEI.  Next,
the end
user takes six-inch long ethernet cables and connects each (now vacant) 
port of the existing switch to the "inputs" of the POEI.

The POEI simply connects the four ethernet signals on each of its
"inputs"
(pins 1,2,3,6 on each) to the same pins on its corresponding
"outputs".
Additionally, it supplies -48VDC (maybe selectable if there are other 
voltage needs) on the appropriate pins (also maybe selectable if different 
vendors use different wiring conventions for POE) of its "outputs".

This could be an inexpensive way to provide POE without having to replace 
all of one's switches.  Additionally, this could be a nifty business 
opportunity.

Are POE switches expensive enough to warrant manufacturing above?
If not, is there a case for not having to swap out all of ones existing 
switches?

Does something like this already exist for cheap?
If so, is it any good?
If so, does it need more features?

If not, would you buy something like this?
If so, what features have I missed?
If so, what is it worth?

Daydreaming, as usual.

Ken

Ken Alker wrote:
> Based on several threads I've read on this list, I assume that it 
> would be handy to supply POE (power over ethernet) in an environment 
> without having to purchase POE switches (assumed expensive) and 
> abandon one's existing (familiar/custom/not-yet-expensed/etc.) 
> switches/hubs.
>
> Assume I have a non-POE switch with 24 RJ-45 (ethernet) ports.  I 
> design a 1U box that can be mounted just above/below the non-POE 
> switch, call it a "POEI" (POE inserter).  This box has 48 RJ-45
ports,
> 24 "inputs" and 24 "outputs".  The end user removes all
the ethernet
> cables connected to the existing switch and moves them to the 
> "outputs" of the POEI.  Next, the end user takes six-inch long 
> ethernet cables and connects each (now vacant) port of the existing 
> switch to the "inputs" of the POEI.
Ken,

The boxes youn describe are already being manufactured by amongst others:
http://www.powerdsine.com/Products/Midspan/

I have no idea on pricing though......

Regards, Michiel

Ken Alker wrote:
> Based on several threads I've read on this list, I assume that it would
> be handy to supply POE (power over ethernet) in an environment without 
> having to purchase POE switches (assumed expensive) and abandon one's 
> existing (familiar/custom/not-yet-expensed/etc.) switches/hubs.
> 

Ken,

such a device (and some more PoE stuff) is available from Powerdsine. 
Don't know what it costs, just wanted to let you know its available.

Jan

Hi.
> The POEI simply connects the four ethernet signals on each of its
"inputs"
> (pins 1,2,3,6 on each) to the same pins on its corresponding
"outputs".
> Additionally, it supplies -48VDC (maybe selectable if there are other 
> voltage needs) on the appropriate pins (also maybe selectable if different 
> vendors use different wiring conventions for POE) of its
"outputs".
and probably you're going to fry something on your lan.
POE isn't simple power on the right pins, but is
a sort of "protocol". Really, on POE enabled devices
(or injectors) you won't measure the DC with a tester,
simply because POE on port X is enabled after a request
by the device on that port. this is for mantaining compatibity
with non POE devices.
so you will need also something that detects the power request
on each port and enables it.

Matteo.

-- 
Matteo Brancaleoni
Espia System Administrator
Email : mbrancaleoni@espia.it
Web   : http://www.espia.it
Phone : +39 02 70633354      - ext 201
IAX(2): guest@213.140.14.155 - ext 201
Iaxtel: 1-700-56-62458       - ext 201

-----Original Message-----
From: Ken Alker [mailto:ken@impulse.net]
Sent: Tuesday, January 20, 2004 2:59 AM
To: asterisk-users@lists.digium.com
Subject: [Asterisk-Users] Power Over Ethernet for *any* ethernet switch
(or hub); product idea

Does something like this already exist for cheap?
If so, is it any good?
If so, does it need more features?

If not, would you buy something like this?
If so, what features have I missed?
If so, what is it worth?

Daydreaming, as usual.

Ken

Ken,

3Com makes a 24-port midspan box that sells for around $800.

Kevin 
  
 
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On Tue, 2004-01-20 at 02:59, Ken Alker wrote:
> Based on several threads I've read on this list, I assume that it would
be
> handy to supply POE (power over ethernet) in an environment without having 
> to purchase POE switches (assumed expensive) and abandon one's existing
> (familiar/custom/not-yet-expensed/etc.) switches/hubs.
> 
> Assume I have a non-POE switch with 24 RJ-45 (ethernet) ports.  I design a 
> 1U box that can be mounted just above/below the non-POE switch, call it a 
> "POEI" (POE inserter).  This box has 48 RJ-45 ports, 24
"inputs" and 24
> "outputs".  The end user removes all the ethernet cables
connected to the
> existing switch and moves them to the "outputs" of the POEI. 
Next, the end
> user takes six-inch long ethernet cables and connects each (now vacant) 
> port of the existing switch to the "inputs" of the POEI.
> 
> The POEI simply connects the four ethernet signals on each of its
"inputs"
> (pins 1,2,3,6 on each) to the same pins on its corresponding
"outputs".
> Additionally, it supplies -48VDC (maybe selectable if there are other 
> voltage needs) on the appropriate pins (also maybe selectable if different 
> vendors use different wiring conventions for POE) of its
"outputs".
> 
> This could be an inexpensive way to provide POE without having to replace 
> all of one's switches.  Additionally, this could be a nifty business 
> opportunity.
> 
> Are POE switches expensive enough to warrant manufacturing above?
> If not, is there a case for not having to swap out all of ones existing 
> switches?
> 
> Does something like this already exist for cheap?
> If so, is it any good?
> If so, does it need more features?
> 
> If not, would you buy something like this?
> If so, what features have I missed?
> If so, what is it worth?
Your main problem is going to be in metering. I think the PoE spec is
some smallish ma rating. If you use some COTS power supply capable of
providing power to all 24 ports, your talking about some pretty hefty
power, and unless you wish to put some form of circuitry to act as a
limiter per port, your could end up with some nasty problems.

Also I believe the spec states -48vdc. IT isn't difficult for a small
power regulator on the device side to make that what it needs inside
after the voltage drop for distance. 
-- 
Steven Critchfield  <critch@basesys.com>

On Tuesday 20 January 2004 10:30 am, Kevin Ragsdale wrote:
> 
> 3Com makes a 24-port midspan box that sells for around $800.
> 
> Kevin 
>   
>  
> This electronic message transmission, including attachments, is for the 
exclusive use of the individuals to which this e-mail is addressed and is to 
be reviewed and used exclusively for authorized company purposes.  This 
transmission may contain proprietary, confidential or privileged information.  
If you are not the intended recipient of this transmission, you are hereby 
notified that any use, copying, disclosure, dissemination, distribution or 
taking of any action in reliance upon the contents of this transmission is 
strictly prohibited.  If you believe you may have received this electronic 
message in error, please notify the sender immediately by return email and 
delete or destroy the original message and/or any copy of it from your 
computer system and/or your files.  Thank you. 


http://www.goldmark.org/jeff/stupid-disclaimers/



-- 
Art is anything you can get away with.
		-- Marshall McLuhan.

> -----Original Message-----
> From: asterisk-users-admin@lists.digium.com 
> [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Ken Alker
> Sent: Tuesday, January 20, 2004 3:59 AM
> To: asterisk-users@lists.digium.com
> Subject: [Asterisk-Users] Power Over Ethernet for *any* 
> ethernet switch (or hub); product idea
> 
> 
[...]
> Assume I have a non-POE switch with 24 RJ-45 (ethernet) 
> ports.  I design a 
> 1U box that can be mounted just above/below the non-POE 
> switch, call it a 
> "POEI" (POE inserter).  This box has 48 RJ-45 ports, 24 
[...]
> Are POE switches expensive enough to warrant manufacturing 
> above? If not, is there a case for not having to swap out all 
> of ones existing 
> switches?
[...]
Depends on what "expensive" means, and whether your switces are due
for
replacemtn or not.  And what you intended to replace them with not
counting PoE.  The difference between Catalyst 2950-XL-24s and
3524-PRW-XL's is about $300.

The difference on a large Catalyst switch is about $5-10/port if I
recall correctly from my last deployment.
> Does something like this already exist for cheap?
Yes.  Several.
> If so, is it any good?
Yes.  Many work just fine.
> If so, does it need more features?
To do what?  It's called a mid-span power injector.  The ones I've seen
do that and nothing else.  I'd say they are living up to their task.
> If not, would you buy something like this?
> If so, what features have I missed?
> If so, what is it worth?
Google the rest of your answers.  You're about 6 years too late to catch
the first run of this train.

Daryl G. Jurbala
BMPC Network Operations
Tel (NY): +1 917 477 0468 x235
Tel (MI): +1 616 608 0004 x235
Tel (UK): +44 208 792 6813 x235
Fax: +1 508 526 8500
INOC-DBA: 26412*DGJ

PGP Key: http://www.introspect.net/pgp

-----Original Message-----
From: Martin [mailto:marrandy@chaossolutions.org]
Sent: Tuesday, January 20, 2004 10:23 AM
To: asterisk-users@lists.digium.com
Subject: Re: [Asterisk-Users] Power Over Ethernet for *any* ethernet
switch (or hub); product idea

<snip>

http://www.goldmark.org/jeff/stupid-disclaimers/

-- 
Art is anything you can get away with.
		-- Marshall McLuhan.

Martin,

We have rules in place that remove it from emails to mailing lists, but I
fat-fingered the digium address.  Should be fixed now.

Apologies,

Kevin

> [...]
>> Assume I have a non-POE switch with 24 RJ-45 (ethernet)=20
>> ports.  I design a=20
>> 1U box that can be mounted just above/below the non-POE=20
>> switch, call it a=20
>> "POEI" (POE inserter).  This box has 48 RJ-45 ports, 24=20
> [...]
>> Are POE switches expensive enough to warrant manufacturing=20
>> above? If not, is there a case for not having to swap out all=20
>> of ones existing=20
>> switches?
> [...]
> Depends on what "expensive" means, and whether your switces are
due for
> replacemtn or not.  And what you intended to replace them with not
> counting PoE.  The difference between Catalyst 2950-XL-24s and
> 3524-PRW-XL's is about $300.
HP Blade Switches (most of the ProCurve range) can take the new HP PoE 
blades (only just started shipping), which essentially upgrade your 
enterprise switch for a hell of a lot less.
> The difference on a large Catalyst switch is about $5-10/port if I
> recall correctly from my last deployment.
It's peanuts really. Compare it to the cost of 48 power adaptors 
(virtually no IP phone is shipped with a PSU).
>> Does something like this already exist for cheap?
> Yes.  Several.
Indeed - we even resell a great brand in the UK
>> If so, is it any good?
> Yes.  Many work just fine.
>
>> If so, does it need more features?
> To do what?  It's called a mid-span power injector.  The ones I've
seen
> do that and nothing else.  I'd say they are living up to their task.
The brand we resell has a number of remote management features - 
allowing you to remotely check on the health of each port, power 
drains, port status and has some remote tools for flashing power, and 
shutting power off to certain ports (like badly wired 10baseT devices 
that may be hard wired to each pin).

Cisco also produces a simple unit called the PWR-PANEL that is just a 
basic injector with RPS options.
>> If not, would you buy something like this?
>> If so, what features have I missed?
>> If so, what is it worth?
> Google the rest of your answers.  You're about 6 years too late to 
> catch
> the first run of this train.
Ditto - we've already got them!

Regards,
Ad.