>“We continue to try and contact the Tonga network operations centre but at this stage remain unable to do so, even via satellite phone. While we understand Tonga also has satellite links, we don’t know whether the satellite ground equipment has been affected.”

The ground link between Fiji and Tonga was broken. Even satellite links are down due the ash cloud. That's why there's no telemetry from anything at all. Hard to imagine but we have no link to Tonga.

https://www.stuff.co.nz/business/127512800/southern-cross-ca...