Direct routing for Azure Communication Services is now available in public preview. Direct routing is a virtual connection between a developer application and the legacy on-premise telephony or carrier used for calls on the public switched telephone network (PSTN). Developers will be able to build calling through PSTN almost anywhere and allow for connections into third-party equipment through a certified session border controller (SBC).
Consumption billing for direct routing begins August 1st, 2021. See pricing details here.
Read the documentation.
Read the blog.
Learn more about Azure Communication Services.