It depends on what desk phones you’re currently using. If you’re currently using analogue handsets its worth upgrading your handsets to receive the full benefits an IP telephone would bring. However, older analogue devices can be connected to our VoIP solution, Daisy Hosted Voice (DHV), via an analogue terminal adapter (ATA).
You actually don’t need a handset at all as with DHV you can use it on a soft phone only.