For use with the BT500D headset Connects your BT500 to your PC or Laptop The headset and USB Dongle are pre-paired and ready for use Softphone interoperability through USB/computer with 3CX, Avaya One-X Agent, Broadsoft UC-one, Cisco Jabber, Counter Path, or Skype for Business with assistance from the JPL Gateway. JPL Gateway software must be installed and running for remote call control functions to work with supported softphones.