Figure 6-2: Customer Premises Equipment Site Handset PBX 4-Pair UTP Telephone Wiring Ⅲ[ PSTN A typical business site The private branch exchange is an internal switch for the site 4-pair UTP was created for business premises telephone wiring Company is essentially its own telephone company that connects to the outside Pstn 6-56-5 Figure 6-2: Customer Premises Equipment PSTN PBX Handset 4-Pair UTP Telephone Wiring Site A typical business site. The private branch exchange is an internal switch for the site. 4-pair UTP was created for business premises telephone wiring Company is essentially its own telephone company that connects to the outside PSTN