[Asterisk-biz] PoE for Cisco Phones

[Roderick Montgomery]

According to Adi Linden:
> 
> But Cisco doesn't do 802.3af ...

This isn't the first time I've seen this meme on asterisk-biz, but I haven't
seen any statements to the contrary. It's just not true.

Cisco developed their IP Phones and inline power before the 802.3af standard
was ratified in June 12, 2003. This method, first introduced in 2000, is
commonly called 'Cisco PoE' or 'pre-standard inline power.' When 802.3af was
finalized (by the IEEE PoE Committee, in which Cisco played a significant
role), Cisco announced support for the standard and has followed through
across their switching platforms, and with 802.3af support in the 7970G.

The following phones can be powered using pre-standard inline power:
  7902G		7905G
  7910G		7910+SW
  7912G		7940G
  7960G		7970G
The 7970 and 7971 concurrently support 802.3af.

Their 802.3af white paper says, "With the ratification of IEEE 802.3af, as
with other Cisco innovations, Cisco will support both IEEE 802.3af and
prestandard Power over Ethernet concurrently. Cisco has also extended
prestandard power management extensions using Cisco Discovery Protocol
negotiation to Cisco IEEE 802.3af compliant devices to further optimize PSE
power management."

Now, I realize that most folks use the 7960 and its lack of 802.3af support
can be frustrating, but comments that infer that Cisco ignores the standard
or won't support it are misleading. They implemented inline power before the
standard, they helped make the standard, and now they're supporting the
standard. Any suggestion otherwise most likely refers to older products.

rm
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 Roderick Montgomery   rod at thecomplex.com   <URL:http://thecomplex.com/>
the fool stands only to fall, but the wise trip on grace... [Sarah Masen]
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