Cisco Inline Powered Switches with Avaya IP 4600 phone

[Ken Snyder]

Hi,

Avaya claims that Cisco uses several powering schemes, which are not in compliance with the proposed IEEE standards for powering IP phones. Avaya’s mid-span power unit, the 1152A1 Power Distribution Unit, does meet the proposed IEEE802.3af standard. I searched around on CCO and found several doc's that state Cisco is working with the IEEE task force to produce a standard but nothing states the switches are actucally in compliance. Has anyone attempted to use a Cisco inline powered switch with the Avaya IP 4600 phone?

-Ken

[mmedwid]

Cisco uses CDP to determine what's at the other end of a port connection and whether to send power down the line. There was no standard 18 months ago and this scheme works pretty well. How does Avia determine whether the device on the end of a switch port is a phone requiring power?

[jmarateo]

Ken

According to Avaya, there IP phones use pins 78 and 45 to supply power. The same if you are using Cisco's inline Power Patch Panel. There are two possible standards (1) Power over Ethernet and (2)power off the un-used pairs. Most likely that the IEEE will ratify both standards.

[mberrocal]

you can see the algorithms used by cisco at

http://www.cisco.com/warp/public/788/AVVID/ip_pwr_detect.html

[letnet]

I think you've hit the crux of the point in your own message - it's hard to meet a standard when it does not exist - as pointed out below, it certainly didn't meet it two years ago and I think we'll all agree CDP is better than power cubes :-)

Avaya's line is marketing my friend - without a ratified standard it doesn't matter a hill of beans if they meet the one that they "think" might get ratified - it's not going to get ratified next week - don't panic.

Equate it with X2 and K56Flex - once there's a standard every vendor under the sun (including Cisco) will have it - no differentation there - at this point everyone's power is proprietary but they've been plannning for a potential switch to a standard for years - not a great way to pick a product there...

(Just my $0.02 :-) And why isn't there a cents symbol on my keyboard :-)

- Ken