Home / server / Questions / 288135
Accepted
joechip
Asked: 2011-07-08 18:56:17 +0800 CST

Are Cisco Small Business 300 series switches compatible with pre-standard PoE detection of old Cisco IP-phones?

  • 772

I have a humble Cisco SF302-08MP managed PoE switch that I'm trying to use for powering an old Cisco 7902G IP phone. This phone uses the proprietary Cisco pre-standard (i.e., non-802.3af) PoE detection method. Connecting the IP phone to the switch results in the phone staying off. The switch has been updated with the latest firmware, but it still doesn't work. I couldn't find any CLI command to activate pre-standard PoE detection on the switch. Both devices are in working order (tested with other equipment). Is it at all possible to use these two Cisco devices together? If so, how?

cisco voip power-over-ethernet

3 Answers

  1. Nope, they don't work together. The 300 series only supports 802.3af. Unfortunately the two standards aren't compatible.

    • 1
  2. Best Answer

    As of September 2011 there's new firmware available for the 300 Series that adds support for Cisco's pre-standard PoE (a.k.a. Cisco Inline Power). See https://supportforums.cisco.com/docs/DOC-18337 .

    • 1

  3. There is an update that fix this. https://supportforums.cisco.com/docs/DOC-18337

    • 1