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We would like to use passive PoE for Cisco CP-7821 IP phones in a special application. Edit: By passive PoE I mean applying voltage without the standardized protocol that determines device class etc before the application of 48V. 1. Does the phone su...
I am trying to get a Cisco IP Phone 7821 to register to an Asterisk PBX. But according to my wireshark log it never even tries to register. It just keeps getting its files from the tftp server in a loop every 3 minutes. The phone display says "Regist...
Thanks, I am referring to providing power directly - without IEEE 802.3af negotiation, - with the pinout of 802.3af mode B which in the final state provides 48V on the two unused pairs in 100Base-TX.No questions that the Cisco phones supports 802.3af...
Thanks, but No, I don’t want to buy passive injectors. We are developing our own PCB. My question is simply if I can add the 48V to the two unused pairs. If I were to use a COTS power supply I would use the ordinary power bricks, but those are not ap...
The power brick is too large and too expensive. We are (based on customer requirements) designing a small box that will sit on the back of the phone. The box will have 230VAC and Optical fiber as inputs. Our box will provide media conversion 100Base-...
The question is if passive POE is supported. I.e. without the standardized protocol to determine device class etc before applying the 48V. Or is this a supported case in the standard?
Old question, but I put an answer here as I had problems finding the answer to the same question.First however, question yourself if you really want to enable SSH as it makes the phone vulnerable, e.g. to DOS attacks. Best security practice is to nev...
