Within the SAFE SMR model, the medium-sized network design consists of three modules:
Corporate Internet module
Campus module
WAN module
Figure 15-1 shows six modules; however, the Public Switched Telephone Network (PSTN), Internet Service Provider (ISP), and Frame Relay/ATM modules are shown for clarity but are not considered a part of the medium-sized network design model:
ISP module
PSTN module
Frame Relay/ATM module
Corporate Internet module
WAN module
Campus module