|  | 2.5 | WAN Link Options
| 2.5.2 | Dedicated lines
Dedicated lines, also called leased lines, provide full-time service. Dedicated lines typically are used to carry data, voice, and occasionally video. In data network design, dedicated lines generally provide core or backbone connectivity between major sites or campuses, as well as LAN-to-LAN connectivity. Dedicated lines generally are considered reasonable design options for WANs. When dedicated line connections are made, a router port is required for each connection, along with a CSU/DSU and the actual circuit from the service provider. The cost of dedicated-line solutions can become significant when they are used to connect many sites.