[cisco-voip] 802.3at and the 9971 / VXC 2112

Mike King me at mpking.com
Fri Feb 3 11:25:02 EST 2012


As an update for google an anyone interested.

This is what I got back from Cisco TAC (I opened a case with both Juniper
and Cisco)

<quote>

I just got an analysis from a switching engineer and here's what we found:



The 9971 phone is sending  TLV of Extended Power-Via-MDI TLV and Power Via
MDI TLV.  Even though as per IEEE standards "An LLDPDU should contain no
more than one Power Via MDI TLV" which seems to be causing an issue between
the 9971 and Juniper switch.  Also the 9971 should send a class of 3 (for
802.3af) and 4 (for 802.3at) but the 9971 is sending class 5 which is not
correct.



I'm going to get in touch with the 9971 phone developers about this now.
</quote>

So a combination of sending Class 5 and two TLV's instead of 1 is what
we're chasing right now.  I personally think the Class 5 (which does not
exist) is the problem.

So the ball is in Cisco TAC's court right now.

On Wed, Jan 18, 2012 at 11:35 AM, Mike King <me at mpking.com> wrote:

> I'm running 8.5.1 and we loaded the latest device pack on cisco's website
> the week of December 28th.
> I've updated to firmware 9-2-3
>
> I've narrowed it down to a LLDP-MED problem.  I just need to figure out
> who's problem it is.   I have a juniper switch, and apparently Juniper and
> Cisco are not agreeing on the LLDP packets.
>
> From the phone, I'm getting TLV timeout
> on the switch, i'm getting TLV discarded
>
> I've opened a support case with Juniper, since it's actively making
> a decision, versus the phone that is just patiently waiting for a response.
> That's not to say that the Phone might be sending a malformed request.
>  I'm sure the first thing the Juniper TAC is going to have me do is a
> packet capture.
>
> Fun times, wohoo.
>
>  Mike
>
>
> On Wed, Jan 18, 2012 at 10:25 AM, Ryan Ratliff <rratliff at cisco.com> wrote:
>
>> What CUCM are you running?  The parameter Adam mentioned is called "Power
>> Negotiation" and should be present on the phone page in CCMAdmin.
>>
>> You should enable the Power Negotiation feature when connected to a
>> switch that supports power negotiation. However, if a switch does not
>> support power negotiation, then you should disable the Power Negotiation
>> feature before you power up accessories over PoE. When the Power
>> Negotiation feature is disabled, the phone can power up accessories up to
>> 12.9W
>>
>>
>> -Ryan
>>
>> On Jan 17, 2012, at 5:20 PM, Mike King wrote:
>>
>> I'm currently running sip9971.9-2-2
>>
>> But I'm not sure how that helps me.  :-)
>>
>> On Tue, Jan 17, 2012 at 4:18 PM, Adam Frankel (afrankel) <
>> afrankel at cisco.com> wrote:
>>
>>>  With the fix for CSCtl08010, you should be able to disable power
>>> negotiation at the device/common/enterprise level in CUCM.
>>>
>>> You also need 9.1(1) or newer firmware.
>>>
>>> Adam
>>>
>>>
>>>  ------------------------------
>>> *From:* Mike King <me at mpking.com> <me at mpking.com>
>>> *Sent:* Tue, Jan 17, 2012 2:49:36 PM
>>>
>>> *To:* Cisco VoIPoE List <cisco-voip at puck.nether.net><cisco-voip at puck.nether.net>
>>> *CC:*
>>> *Subject:* [cisco-voip] 802.3at and the 9971 / VXC 2112
>>>
>>>  We have a 9971 phone with the VXC 2112 backpack, and we've connected
>>> it to one of our Juniper switches that provide 802.3at power.
>>>
>>>  However the backpack (or the camera) does not appear to work with it.
>>> (Works fine with the power cube)
>>>
>>>  Is there anything we have to do to enable PoE Plus (802.3at)?  I know
>>> the switch is providing it. (Its registering it as a class 4 device, but
>>> the phone is only drawing 7.4W, out of a Max of 30W)
>>>
>>>  Mike
>>>
>>>
>>> _______________________________________________
>>> cisco-voip mailing listcisco-voip at puck.nether.nethttps://puck.nether.net/mailman/listinfo/cisco-voip
>>>
>>>
>>>
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>>
>
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