I come from a Cisco background and when configuring a Cisco phone system, in order test call-flow and phone behavior I would install a product called IP Communicator which is effectively a softphone client that allows you to configure it with an extension in whatever site or location you wish and then make calls and check how everything is working. This usually runs over a VPN connection that has access to the phone system.
It makes testing things like call restrictions, caller ID, trunk selection etc much easier than having to either attend site and use a physical phone or asking an end-user to dial a certain number and let me know the result.
Is there anything similar in the Mitel world that's relatively simple to setup? I've tried Micollab/MBG but always end up with a registration rejected message when trying to activate the softphone component so no doubt I've missed one of the seemingly countless steps needed to get it working.
Would a SIP softphone (like 3CX) work if configured as a generic SIP phone?