While it is possible for things to break with firmware updates, completely disabling calls isn't usually one of them, so there is likely another configuration issue somewhere that is being affected by the update. It is hard to provide much detail on what your issue could be without further information on your environment, like what control platform are you using? Are the calls/registrations H.323 or SIP? Are the devices showing as registered correctly on the endpoint's web interface? Are there any errors showing on the device?
Wayne
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