Chapter Summary Continued
The Physical layer WAN connections concern the interface between the DTE and DCE.
The DTE is the endpoint of the user’s network, which connects to the WAN interface.
The WAN service provider typical provides the DCE, which is often a CSU/DSU, modem, or terminal adapter.
The DCE is then connected to a demarc, which is a communications facility owned by the WAN service provider.
The local loop is the connection (usually copper cable) that connects the demarcation to the WAN service provider’s CO Switch, which is actually part of the toll network or PSTN.