[TriLUG] Re: voip (POE)

[Ron Joffe]

On Thursday 19 February 2004 15:53, elfick wrote:
> During the presentation you had mentioned using switches that support
> POE. Are there any switches out there that support POE that don't break
> the bank (i.e. aren't cisco)?


Just a quick note about POE (power over ethernet). Basically what you see is 
not what you get :( . I have a Cisco 3524 switch with POE, and I also have an 
IP phone (Snom 100) which is also POE, but the two don't talk.

It seems that there are more then one method of communication between the POE 
server (i.e. the switch) and the POE client (i.e. the phone). The issue has 
to do with how the phone asks the switch to turn on power on the particular 
port to which it is connected. From what I read of the specs (IEEE POE specs) 
is that there are a number of signaling methodologies in place. The power 
lines aren't hot all the time, and are activated only after a successful 
"handshake" between the client and server.

In my case it seems that the Cisco 3524 and the SNOM 100 are not compatible 
for the POE portion. I researched this thouroughly, and it seems that some of 
the Cisco devices would be compatible, but I already have the 3524 :(.

Ron