You will struggle to sort licenses and keys out for the 400 given its been discontinued.
Originally Posted by oxide54
The 450 was a relatively simple upgrade and actually takes the entire unit up to a much higher standard and powerful system, although again it is short lived we will have to reconsider what we do in the next 3-5 years but gives us the time to plan and budget to change to probably MS Lync would be ideal.
With the FreePBX solution it took me around a week to play with it and configure how I wanted for the school and the roll out was really simple, setup a PXE boot on the freepbx server and all the phones pxe booted to get configs - which where all done via a barcode scanner on the box and a bit of word mail merge's with a bolt on to seperate them to new files.
Plugged each phone in and put on correct vlan and walked away.