Leased Lines (LL) are circuits of permanent, dedicated and usually symmetric capacity, which enable transparent voice and data transmission between their termination points. Wholesale LL are used by providers either for their own use in deploying their network or to provide services to retail (corporate) customers.
Depending on their technology, wholesale LL may be analog, traditional digital (SDH, PDH) or Ethernet. In addition, they are classified based on their capacity and physical transmission medium (an optic fiber, copper or wireless medium). LL are distinguished into terminating segments and trunk segments of leased lines based on the needs they serve.