Legend R7, point-to-point PRI, Paradyne CSU each end to D100. Have developed a pronounced echo only on remote end, otherwise audio is crystal clear. More pronounced on CO calls but system-system intercom has them, on remote only. Outgoing over direct CO w/o routing to PRI are clear. All modules and cables have been reseated but no change. Suspect something in software as each end had some recent program changes, but I can see nothing out of ordinary and do not recall any intentional changes to PRI. Error Events at each end show no problems. Likely spots to look??