Telecom Basics, Second Edition
This guide presents the groundwork of telecom technolgies, network, systems, and call processing.
TABLE OF CONTENTS Telecom Basics, Second Edition
Chapter 12: Call Processing
Call processing is the steps that occur during the duration of a call. These steps are typically associated with the routing and control of the call. Call processing may involve several processes that are performed by a combination of the public switched telephone network, private telephone network, or intelligent (switching) network. This chapter provides a description of some of the more popular call processing procedures.
Distinctive Ringing
Distinctive ringing is a service feature that alerts a customer via a special ring (usually short, long or rapid ring) that an incoming call is received that has a different purpose or priority from others that are received on that same telephone line. Distinctive ringing is used for sharing multiple phone numbers on a single line or for priority ringing.
Figure 12.1 shows the operation of a telephone system that has distinctive ringing feature. This diagram shows a single telephone that is assigned two different telephone numbers even though the telephone operates on one telephone number (one switch port). In this example, when an incoming call is received for the registered number 555-6234, it is re-directed (forwarded) towards the actual destination number 555-1234 along with information that allows the system to uniquely identify the call with a dual ring (2 rings in the 2 second ring period). When calls are received to 555-1234, the ring is a single 2 second/4 second cadence. This allows the receiver of the call to determine which telephone number was dialed by the distinctive ring sound.
Figure 12.1:
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