1. T1 lines can use twisted-pair, coaxial or fiber-optic cabling while T3 lines can use coaxial or fiber-optic cabling

2. Multiplexing enables several communication streams to travel simultaneously over the same cable segment

3. Time division multiplexing (TDM) is a signaling method thatallocates a time slot for each channel of T1.

4. VPN is the most expensive WAN connectivity

5. Many WAN technologies are available and differ in speed, level of security and reliability, and cost. Leased line and VPN are the most common connection methods

6.