Gambler,
If you mean the old Inter-Tel CS controller called the CS-5000 or Inter-Tel 5000 and then the Mitel 5000 followed by the MiVoice Office 250 then yes.
If you are referring to the Aastra 5000 that then became the Mitel 5000 when the old one became the MiVoice Office 250 then no.
The way to know is whether or not it is a SIP based system.
Thanks,
TE
