We have both Phone System (implemented when it was Cloud PBX) using CCE and an Avaya PBX. Our dial plan and numbers are on-premises with access to PSTN for Phone System through a CCE connection to the Avaya PBX. We have both Avaya and Phone System users. What will happen when Skype for Business is deprecated in favor of Teams when Teams calling cannot use CCE for PSTN. What happens to our current Skype for Business Phone System users? What is the future for customers using CCE?