This excellent paper can help explain some of the complexities of signal reflections...

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 20, NO. 5, JUNE 2002

Loop Makeup Identification Via Single Ended Testing: Beyond Mere Loop Qualification

By: Stefano Galli, Member, IEEE, and David L. Waring, Senior Member, IEEE

http://www.argreenhouse.com/papers/sgalli/JSAC_LoopID.pdf

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