I have a PRI on an EL system lw19

in maintenance, reports, show errors my PRI card bay 4, slot 6, I show 99 slips per hour. Frame and Bipolar are 0

System works fine but my modem for rmats via a DID is barely working. I dropped alot on modem calls. I switched modems/ons ports, no change. I am curious if the slips are the reason? System last rebooted in 18 months.

can the Pri provider check the line, where I am the provider installs a HRU which is their demarc and they can go into the HRU remotely and tell if the slips are on the line or coming from the pbx. Might be a cable pair going bad

Did you double check that your Synch Source is set in form 44?