We have used VoIP for four years with no issues.  On December 7, Shaw swapped our modem.  No issues, just apparently necessary due to upgrades.  The new modem is a CODA-4582 in bridge mode.  We use a Tomato router configured with a static IP.

Today, all our VoIP phones experienced a no audio issue, despite the the phones using TLS, modem being in bridge mode, no changes made to the router since 2017, and other internet traffic working properly.  Rebooting the router and the phones did not solve the problem.  Rebooting the modem solved the problem.

Any suggestions for how to prevent this from happening again would be appreciated.