a. Draw an annotated end to end telephony network system to differentiate the following:

a local loop; subscriber’s line, local switch, trunk switch, trunks (interchange carriers).

b. Draw a simplified block diagram of the South African telephony network, including the core-network, zone codes, and area codes (kzn only). Illustrate how

i. An outgoing international call

ii. Incoming international call

iiii. Local how

iv. National call will be routed across the network

c. Provide a simple classification of the various types of network.

d. Demonstrate, your understanding of the phrase, “ a telephony network is hierarchical in nature”.