As its name implies, FreeSWITCH will "switch" or "connect" various endpoints together. Part of that switching involves making semi-permanent connections to individual telephones or telephone service providers. Service providers are usually telephone companies (telcos) or ITSPs (Internet Telephony Service Providers). Read on to learn about the many ways that FreeSWITCH can connect your telephone to the world.
The recipes in this chapter will delve into the various ways to connect FreeSWITCH to telephones and service providers. FreeSWITCH can also utilize a locally installed sound card by means of the PortAudio library. The last recipe is for advanced users and discusses the subject of codec negotiation.