Attenuation at U-link point in DDF

In Ericsson DDF there is a U-link that connects the incoming and outgoing E1 co-axial cables from exchange. What level of signal is lost at that point. Reason for this question is there is plan to extract signal from the monitor port of U-link. So the attenuation level is needed so that the signal can be tapped without issue.

Thanks,
Ram