Figure 6-1: Elements of the Public Switched Telephone Network(PSTN The Access System consists of the access line to the customer (called the local loop) and termination equipment at the end office (nearest telephone office switch) 2 2. Access line Access Line (Local Loop) (Local Loop 2&3 end office Switch( Class 5) 6-6
6-6 Figure 6-1: Elements of the Public Switched Telephone Network (PSTN) 2. & 3. End Office Switch (Class 5) 2. Access Line (Local Loop) 2. Access Line (Local Loop) The Access System consists of the access line to the customer (called the local loop) and termination equipment at the end office (nearest telephone office switch)
Figure 6-1: Elements of the Public Switched elephone Network(PSTN) 3. Transport Core 3. Switch 3. Trunk Line The Transport core connects end office switches and core switches Trunk lines connect switches 6-7
6-7 Figure 6-1: Elements of the Public Switched Telephone Network (PSTN) 3. Transport Core 3. Trunk Line 3. Switch The Transport Core connects end office switches and core switches. Trunk lines connect switches
Figure 6-1: Elements of the PSTN Telephone Company Switch " t 22国 ,是 6-8
6-8 Figure 6-1: Elements of the PSTN • Telephone Company Switch
Figure 6-1: Elements of the Public Switched Telephone Network(PSTN) 净 4. Signaling System Transport is the actual transmission of voice Signaling is the control of calling (setup, teardown, billing, etc. SS7 in the United States C7 in Europe 6-9
6-9 Figure 6-1: Elements of the Public Switched Telephone Network (PSTN) 4. Signaling System Transport is the actual transmission of voice. Signaling is the control of calling (setup, teardown, billing, etc.). SS7 in the United States C7 in Europe
I Figure 6-3: Points of Presence(POPs) Local Access and Transport Area ( LATA) Other Local area Local Long-Distance POP Carrier 1 Carrier a POP Sw itch E International CarrierⅩ Local Carrier 2 Sw itch Other Country Local Local In the U.s., competing Carrier 1 Carrier 2 carriers connect at Customer Customer points of presence(POPs) 6-10
6-10 Figure 6-3: Points of Presence (POPs) In the U.S., competing carriers connect at points of presence (POPs). Local Access and Transport Area (LATA) Local Carrier 1 Sw itch Local Carrier 2 Sw itch POP Local Carrier 1 Customer Local Carrier 2 Customer Other Local Area Other Country POP Long-Distance Carrier A International Carrier X