NEC SL1100 needs power cycle

Recently the SL1100 has not been allowing users to call outside extensions on the network (forgive any words used incorrectly. This is not within my wheel house) and to correct it we're having to power cycle the black box hanging on our wall. IT has stated they see no errors on their end and are currently trying to find an outside company to troubleshoot. On the lower right side of this black box I see a blue light that flashes. I get 2 blue and 1 red. This is the case even when the outside extensions are working. Any ideas on why this is happening? Ideas on how to correct the issue?

Any help or insight is appreciated.