This read-write enumerated setting programs the receiver sensitivity of the T1 line, choosing between t1e1EGLLow(1) for a -30 dB sensitivity recommended for most applications, and t1e1EGLHigh(2) for a more sensitive -36 dB setting used in specific applications at the cost of greater susceptibility to crosstalk and reduced jitter tolerance. Administrators, under qualified supervision since this is a private-mode setting, adjust it when a T1 line runs over a longer or noisier cable span than the default sensitivity can reliably receive. For example, an admin might switch to t1e1EGLHigh(2) on a long cable run where the default low-sensitivity setting fails to recover the signal.