el is called a frame. not necessarily imply that full-duplex transmission can be achieved through simultaneous use of both pairs. Very long-distance circuits require echo suppressers Convergence technologies that effectively disable one pair of a four-wire circuit while the other pair is in use. Thus only one pair can be Telecommunications convergence is the merger of used at a time. Long-distance (four-wire) leased lines legacy-based TDM architecture with today's packet- for data communications typically have the echo switching technology and call-control intelligence, suppressers removed so that both pairs can be used which allows commercial carriers and service providers simultaneously. to consolidate voice and data networks to provide Data and voice traffic CHAPTER 3.1 Regular, sequential order Input channels Typical scanner output Random access non-sequential order Typical multiplexer output Figure 3.1-8 Time division multiplexing techniques. integrated communications services. Convergence in dial data access. Rather than create a new class of technologies are changing the way telecommunications equipment to divert data traffic from the PSTN, it is companies will provide voice and data traffic. The more prudent to develop strategies that leverage existing public switched telephone network (PSTN) is one of features found in the voice network today. What makes the most reliable communications networks in a converged network work is the ability to control both existence. Using traditional PSTN services as an access networks from one platform simultaneously while being point to the Internet has significantly encouraged the able to manage call-control and multiple protocols from growth of data over costly Class-5 facilities, resulting in different switch applications. the need to reengineer this traditional TDM architec- The SS7 network is the vital link between the voice ture. Convergence technologies will provide a packet- and data networks. SS7 enables routing and control of based architecture that combines th