[Asterisk-Users] Polycom 501 power over ethernet

Douglas Garstang dgarstang at oneeighty.com
Sun Mar 5 20:56:25 MST 2006


Not true. Some do and some don't. Some have a place to plug a separate DC adapter, and some have the inline power, where the adapter plugs into the ethernet cable. Not sure which ones are newer, and which are older.

	-----Original Message----- 
	From: Michael Welter [mailto:mike at telecommatters.net] 
	Sent: Sun 3/5/2006 6:50 PM 
	To: Asterisk Users Mailing List - Non-Commercial Discussion 
	Cc: 
	Subject: Re: [Asterisk-Users] Polycom 501 power over ethernet
	
	

	The IP501 does not have a power jack.  You'll need one of the Polycom
	cables.
	
	William M Conlon wrote:
	> My recollection of the marketing fluff was that we would just use our
	> legacy network (cables) and the devices at both ends would figure out
	> whether they were sourcing, sinking, or neither.  In the case of the
	> 501, it's the special Polycom cable, either with or without provision
	> for an AC power adapter, that powers the phone.  That's what I meant by
	> saying the '501' itself is not compliant with 802.3af -- it needs a
	> separate thingamajig [tech jargon :)]to be powered.
	>
	> Anyway I had hoped that I could just plug a CAT-5 patch cable from my
	> RJ45 wall outlet into the phone.
	>
	> On Mar 5, 2006, at 5:17 PM, Michael Welter wrote:
	>
	>> As I understand 802.3af, the phones go through a negotiation with the
	>> unit supplying the power.  I don't think it's a matter of -48VDC on a
	>> particular pair.  I remember a schematic from years ago--it had each
	>> of the receive pair and the transmit pair going into a transformer
	>> winding,  and that winding had a center tap for PoE.  This is not
	>> something that *I* am going to screw with.
	>>
	>> The IP501 telephone set is the same for both PoE and local power. 
	>> With the PoE cable, the 802.3af electronics (the negotiator) is a
	>> plastic thing in the cable.  For the local power, there is a plastic
	>> thingie toward the wall end of the cable, and you plug the wall wart
	>> into the plastic thingie.  <Notice the advanced technical jargon here>
	>>
	>> With local power, there is still only one cable one the desk--the
	>> power plugs into the cable towards the wall.  Except for a power
	>> interruption, this has all the advantages of PoE.
	>>
	>>
	>>
	>> William M Conlon wrote:
	>>> I saw that Polycom offered a cable (not stocked anywhere), at $40 a
	>>> pop for 802.3af connections.  That's what made me think the phone
	>>> itself is NOT 802.3af compliant.
	>>> Presumably, for $40, there's more than a fuse in that special cable.
	>>> On Mar 5, 2006, at 4:31 PM, Paul Hales wrote:
	>>>> For Polycom IP500/501's and IP300/301's you need a special polycom POE
	>>>> cable.
	>>>>
	>>>> When you buy Polycom phones you can usually specify POE or powerpack.
	>>>>
	>>>> PaulH
	>>>>
	>>>> On Sun, 2006-03-05 at 16:23 -0800, William M Conlon wrote:
	>>>>> When I bought two Polycom 501 SIP phones, I naively thought they were
	>>>>> Power-over-Ethernet (IEEE 802.3af) because they were "powered over
	>>>>> ethernet."  Silly me.
	>>>>>
	>>>>> Polycom must have some odd voltage or funny way of injecting the
	>>>>> power, because the POE switch I bought for them (Netgear F at 510P)
	>>>>> won't power them, though if I use the Polycom-supplied AC adapter and
	>>>>> ethernet power injector cable, they work with the switch in either
	>>>>> its powered or unpowered ports.
	>>>>>
	>>>>> Anyhow, I hadn't seen any mention of how people power these phones,
	>>>>> as I had planned on centralizing phone power on a UPS to supply my
	>>>>> Asterisk server and POE switch.  Now the question is:
	>>>>>
	>>>>> Can the Polycom AC-powered injector be used with a standard ethernet
	>>>>> patch cable:
	>>>>>
	>>>>>     switch :: Polycom injector cable :: RJ45 coupler :: patch cable ::
	>>>>> Polycom 501
	>>>>>
	>>>>> which would allow me to power the Polycom AC adapters by my UPS.  Or
	>>>>> do I need to provide a UPS at each phone and run the ethernet like
	>>>>>
	>>>>>     switch :: patch cable :: RJ45 coupler :: Polycom injector cable ::
	>>>>> Polycom 501
	>>>>>
	>>>>> thanks.
	>>>>> _______________________________________________
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	>>>>
	>>>> _______________________________________________
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	>>> Bill
	>>> William M. Conlon, P.E., Ph.D.
	>>> To the Point
	>>> 345 California Avenue Suite 2
	>>> Palo Alto, CA 94306
	>>>    vox:  650.327.2175 (direct)
	>>>    fax:  650.329.8335
	>>> mobile:  650.906.9929
	>>> e-mail:  mailto:bill at tothept.com
	>>>    web:  http://www.tothept.com
	>>> _______________________________________________
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	>>>   http://lists.digium.com/mailman/listinfo/asterisk-users
	>>
	>> --Michael Welter
	>> Telecom Matters Corp.
	>> Denver, Colorado US
	>> +1.303.414.4980
	>> mike at TelecomMatters.net
	>> www.TelecomMatters.net
	>> _______________________________________________
	>> --Bandwidth and Colocation provided by Easynews.com --
	>>
	>> Asterisk-Users mailing list
	>> To UNSUBSCRIBE or update options visit:
	>>   http://lists.digium.com/mailman/listinfo/asterisk-users
	>
	> Bill
	>
	> William M. Conlon, P.E., Ph.D.
	> To the Point
	> 345 California Avenue Suite 2
	> Palo Alto, CA 94306
	>    vox:  650.327.2175 (direct)
	>    fax:  650.329.8335
	> mobile:  650.906.9929
	> e-mail:  mailto:bill at tothept.com
	>    web:  http://www.tothept.com
	>
	> _______________________________________________
	> --Bandwidth and Colocation provided by Easynews.com --
	>
	> Asterisk-Users mailing list
	> To UNSUBSCRIBE or update options visit:
	>   http://lists.digium.com/mailman/listinfo/asterisk-users
	>
	>
	
	--
	Michael Welter
	Telecom Matters Corp.
	Denver, Colorado US
	+1.303.414.4980
	mike at TelecomMatters.net
	www.TelecomMatters.net
	_______________________________________________
	--Bandwidth and Colocation provided by Easynews.com --
	
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