asterisk users - Nov 2004 - D-LINK PoE switch, does it work with cisco or do I need to do the cable trick?

As an alternative to the "expensive" PoE switches out there, I found
the
D-Link Web Smart DES-1316 switch for just around $400.  Now, the issue 
is, it does 802.3af power and, as I've found out through previous 
discussions, this original 76?0 series phones (the non G variety) do not 
use 802.3af.  So I'm assuming I just need to use the special cable thing 
as per http://www.voip-info.org/wiki-Cisco+POE and it will work.  Is it 
this simple to save myself $1000 over the next lowest price PoE switch?

> As an alternative to the "expensive" PoE switches out there, I
found the
> D-Link Web Smart DES-1316 switch for just around $400.  Now, the issue 
> is, it does 802.3af power and, as I've found out through previous 
> discussions, this original 76?0 series phones (the non G variety) do not 
> use 802.3af.  So I'm assuming I just need to use the special cable
thing
> as per http://www.voip-info.org/wiki-Cisco+POE and it will work.  Is it 
> this simple to save myself $1000 over the next lowest price PoE switch?
To the best of my knowledge, both the 7960 and 7960G are Cisco pre-standard
PoE.  The 7970G is 802.3af.

Now, there's something you need to know:  802.3af compliant switches are not
supposed to just put out voltage.  There's some sort of protocol used to
negotiate power between a device and a switch, and without that, the switch
will not send power.

The little cable scheme on the Wiki assumes a "dumb" PoE injector
which is
basically little more than a DC power supply dumping current on the spare
pairs to power an 802.3af compliant device.  Apparently devices will accept
power just fine even without negotiating, and that applies to Ciscos as 
well with the reversed-lead modification on the Wiki.

On a smart switch, however, I wouldn't expect it to happen, since power
will not have been negotiated.

You might still find that switch and a bunch of 3CNJVOIP-CPOD to be cheaper
than a Cisco compatible PoE switch, however.

Regards,

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance
[and] then I
won't contact you again." - Direct Marketing Ass'n position on
e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many
apples.

> -----Original Message-----
> From: asterisk-users-bounces@lists.digium.com 
> [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of 
> Daniel Chester
> Sent: Monday, 29 November 2004 2:28 PM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: [Asterisk-Users] D-LINK PoE switch, does it work 
> with cisco or do I need to do the cable trick?
> 
> 
> As an alternative to the "expensive" PoE switches out there, 
> I found the 
> D-Link Web Smart DES-1316 switch for just around $400.  Now, 
> the issue 
> is, it does 802.3af power and, as I've found out through previous 
> discussions, this original 76?0 series phones (the non G 
> variety) do not 
> use 802.3af.  So I'm assuming I just need to use the special 
> cable thing 
> as per http://www.voip-info.org/wiki-Cisco+POE and it will 
> work.  Is it 
> this simple to save myself $1000 over the next lowest price 
> PoE switch? 
It depends on whether the D-LINK injects the power into the "unused
wires"
or whether it injects the power into the TX and RX pairs? Look at the UPDATE
at the bottom of the page you mentioned. 3com inject the power into the TX
and RX pairs, so if the end device is not fully 802.3af compliant in anyway
(like these Cisco phones), then to bad, or buy the 3com covertors first. -
http://www.3com.com/products/en_US/detail.jsp?tab=features&pathtype=purchase
&sku=3CNJVOIP-CPOD
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Daniel Chester wrote:
> As an alternative to the "expensive" PoE switches out there, I
found the
> D-Link Web Smart DES-1316 switch for just around $400.  Now, the issue 
> is, it does 802.3af power and, as I've found out through previous 
> discussions, this original 76?0 series phones (the non G variety) do not 
> use 802.3af.  So I'm assuming I just need to use the special cable
thing
> as per http://www.voip-info.org/wiki-Cisco+POE and it will work.  Is it 
> this simple to save myself $1000 over the next lowest price PoE switch?
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Daniel,

	I just ordered a 1316 today, and I have a Cisco 7960 (and IP600's - 
they should be fine).  I will try natively and the cable "trick" and
let
everyone here know.  I think that the cable trick should be necessary, 
though...

--
Kristian Kielhofner