Telecom 101  .  .  .  the basics . . . are often minimized, or left out entirely.  Committees are formed, complex designs are completed, and the services are installed  .  .  .  yet when the customer calls with a question about an interface, or throughput - the answer is not always available.

Here we discuss the fundamental operation of T-Carrier voice and Data circuits. 

*** a few other excellent general, "Telecom 101" type websites :

Vendor Telecom 101 Website
Xytrax  Telecom Tech Info Pages
Verizon Telecom 101
Ericsson Understanding Telecommunications