Is there a way to add a SIP phone to a Mitel SX-200 through some sort of ATA or other device that the SIP phone would register to and convert the SIP to analog to connect to an ONS port.
Looking at a wireless solution to broadcast through a whole hotel, and thinking DECT might not work.
SIP is not supported on any SX-200 platform or software version, neither SIP trunks or stations... Sorry, but if it isn't analog, DNIC, or MiNET you are out of luck.
That said, you MIGHT have some luck using a FXS/FXO device and configuring it in reverse but I have a feeling it would be kludgy and unreliable. It would be purely trial and error on your part
There are DECT phones that connect to POTS lines and any of them should work fine, and analog cordless phones with pretty incredible range like Engenius cordless phones
