Cisco Voice Technologies, now typically referred to as Unified Communications Technologies, not only depend on a solid network foundation, but also use conceptual building blocks from the world of traditional telephony. The reasons for this are:
Capability to interconnect the Unified Communications Environment to the PSTN
Creating “new world” equivalent logical functions that mimic “old world” methodologies
Understanding the basic elements utilized in older telephony can help in knowing how these same functions are created in Unified Communications networks. Here we will map out the basics of an analog telephone call.