Plenty of Iwatsu systems still out there. We had to add a couple of SIP ATAs at a medical site and install 4 or so trunks into the 408 cards in the ECS. They've had a PRI for years, before that I assume analog trunks since they had 408 cards. Like many places, they require patients to call before entering the building.
Callers were getting busies big time before adding the trunks.

I went over the Call Processing menu of another medical facility. We were getting frequent busies to the main number while testing off site. I suggested they re-record the very lengthy main greeting to include the new Covid info option first to try to get callers to listen to what they need, then hang up to release the trunk,

Our in-house test ECS voicemail has the 4 port expansion card installed. Off hand don't know which model the voicemail card is. As old as the system is, we have another ECS customer who wants to add 5 more IP phones, preferably 5900s. The IP Icon phones are especially getting hard to come by.

I've heard now that vaccine rollouts are underway - websites also are experiencing trouble due to so much traffic.