More problems that system does not support
ring groups although if you use disa you can ring a whole ext group in theory.Next problem
There is no intercept routing so the best you'll get is a 15 second ring delay then bang the voicemail answers.Believe me many have failed that box just is not flexible .If you had overhead paging you may be able to get the tva
to hold the call via auto attendant and page
overhead over and over again and say "incoming Call....."