I stopped at my local favorite pizza place and noticed these Avaya digital telephones. It’s really hard to tell if these sets are indeed 9408 or 9508 digital sets. To add to the confusion, there is also a 9608 IP telephone that looks identical. I checked out the cable on the backside of the phones and it was an RJ-11 so it’s a digital telephone, not IP.
These new sets are consistently being installed to replace Partner system telephones. In fact, this pizza joint used to use the Avaya Partner phones and one day I came in to see these new phones. More than likely they are connected to an Avaya IP Office.