Despite us fearing the free voice service to already have disappeared, Vivox had an outage and seems to be back online. The server that is used for open simulator voice seems to be available again. This does however change nothing about their earlier communications regarding their intentions with this service. We still expect the service to stop in the near future, as a 3 years notice is more then polite. Hence the earlier assumptions in the previous post.
OSgrid setup a discord server for offline communications. Inworld there is a backup Mumble server for all Plaza’s in case vivox voice is / goes unavailable. You can click the signs in the plaza for instructions on how to connect. If you run regions of your own, (and still have a vivox account) you should think about how relevant voice communications are for you and your region(s) in the future.