Where along the line must the monitor point be installed?
It does not matter. A monitor point can be installed at any point between the two systems communicating over an E1/T1 line. Some installations have a patch panel near one of the two systems, this is a good spot. Some systems have built-in monitor points. There are, however, some restrictions on the monitor point itself. The distance between the E1 line and the resistors must be short, 1m maximum. The distance from the resistors to the GTH system can be 200m maximum.