Figure 4-1 ADPCM (adaptive differential pulse code modulation) Difference

Figure 4-2 Local exchange network International Carriers Interexchange Carriers Internet Service Providers Cellular Providers Business PBX Customer Premises Equipment Residential Customer Local Loop LECs Local Exchange Network

Figure 4-3 Virtual Private Network Auckland 201 Paris 202 London 203 Johannesburg 205 New York 204 SMS NCP SMS - IXC POP SMS – Service Management System NCP – Network Control Point

Figure 4-4 Interoffice Signaling Switch Loop Signaling Interoffice Signaling

Figure 4-5 Call Setup and Transmission Send dial tone Receive and translate digits Seize trunk Disconnect. Translate digits Seize trunk Disconnect Translate digits Seize trunk Disconnect Receive digits Ring phone Disconnect Phone answered Hang up Phone off hook Call Setup Communicating Call termination LEC Central Office IXC Tandem ACDBEF

Figure 4-6 Call setup using common channel signaling Switch B’ is located at CO B Switch E’ is located at CO E LEC Central Office IXC Tandem ACDBEF Switch E’Switch B’ Note: Voice path and signal path separate STP SCP Database SSP

Figure 4-7 SS7 Architecture SCP SSP STP SSP = Service Switching Point STP = Signal Transfer Point SCP = Service Control Point Signaling Links SCP

Figure 4-8 SS7 Layers Compared with the OSI Reference Model OA&M Network Service Part Signaling network _____________________________ Signaling Link _____________________________ Signaling data link TCAP ___________ Presentation ___________ Session ___________ Transport Network Applications 7 Application ____________ 6 Presentation ____________ 5 Session ____________ 4 Transport ____________ 3 Network ____________ 2 Data Link ____________ 1 Physical ISDN Service User Part ISUP SSCP (Signaling Connection Control Part) TCAP = Transaction Capabilities Application part OA&M = Operations, Administration & Maintenance MTP = Message Transfer Part SS7 LayerOSI Layer MTPMTP

Figure 4-9 A Digital Central Office ALIDLIATIRLIDTI TDM Digital Phone Analog Phone FAX PBX CPU CS PS MCC Test monitor Line and Trunk Interfaces ALI - Analog Line Interface DLI - Digital Line Interface ATI - Analog Trunk Interface DTI - Digital Trunk Interface RLI - Remote Line Interface TDM - Time Division Multiplexer CPU - Central Processing Unit PS - Program Store CS - Call store Switch Features ACT - Automatic Coin Telephone AMA - Automatic message accounting ANI - Automatic Number Identification LIT- Line Insulation Test System LMS - Local Message Metering System MCC - Maintenance Control Center TMS - Transmission Measuring System TTS - Trunk Testing System Class 5 Switch Components Remote Line Interface Trunks to Other COs ISDN Phones

Figure 4-10 An AIN (Advanced Intelligent Network) STP SS7 Network SCP CO SSPIP CO Central Office SSP Service Switching Point STP Signal Transfer Point SCP Service Control Point IP Intelligent Peripherals Customer Systems

Figure 4-11 IXC Tandem Switch Architecture IMT Intermachine trunk DAL Dedicated access line FEX Foreign exchange FGA Feature group A FGB Feature group B FGD Feature group D LEC = End Office PBX IMT LATA FGB (trunk side) FEX FGA (line side) FGD LEC DAL Tandem Switch Phone Operator Console

Figure 4-x An Intelligent Network

Figure 4-7 SDH/SONET Architecture

Figure 4-11 Common Channel Signaling

Figure 4-12 SS7 Network

Figure 4-1 Digitizing a Voice signal Quantizing Noise

Figure 4-5 SONET/SDH Architecture Protect Fiber Counter-clockwise Primary Fiber Clockwise SONET Multiplexer SONET Multiplexer DLC Administrator DLC Administrator

Figure 4-6 Terminal Multiplexers and Add/Drop Multiplexers Terminal Multiplexer Add/Drop Multiplexer High Speed Low Speed DS Mbps to OC Mbps OC Gbps DS Mbps to OC Mbps OC Gbps

Figure 4-8 SS7 Layers Compared with the OSI Reference Model Signaling network Signaling Link Signaling data link TCAP Presentation Session Transport Network Applications OSI Layers Application Presentation Session Transport Network Data Link Physical ISDN Service User Part ISUP SSCP (Signaling Connection Control Point) OA&M Network service part MTPMTP TCAP = Transaction Capabilities Application part OA&M = Operations, Adminiaration & Maintenance MTP = Message Transfer Part