[Asterisk-Users] Polycom 501 power over ethernet

[Michael Welter]

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.
>>>>> _______________________________________________
>>>>> --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
>>>>
>>>> _______________________________________________
>>>> --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 --
>>
>> 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