How do I park a call?

Technical explanation of Call Parking:

PBXtra uses extensions to keep track of just about every element of the phone system.  People have extensions, groups have extensions, and calls are parked at extensions.  Think of extension 9000 as the company receptionist.  When you park a call, you're asking the receptionist to temporarily assign an extension to that call for later retrieval and putting the call into a 'waiting room' of sorts.  When you wish to return to the call, you needn't go to the receptionist again, you can simply proceed directly to the location of the parked call (in this case - an extension).

Extension 9000 will never be the location of a parked caller.  Parked callers begin at extension 9001.