After voip.ms switched to "more secure severs" my call-waiting stutter dial tone disappeared.
I logged into my Obi202 and there's no checkmark in "MessageWaiting" under Voice Services->SP1 Service.
As usual, I unticked "Default", put a tick in MessageWaiting and rebooted, but no matter what, MessageWaiting remains unticked.
I think voip.ms's servers now lack some crucial feature but they say no, it's a fault with the Obi.
I've tried my spare Obi200 and it's the same. I updated its firmware and it's still the same. I reset to default, set it up again and still no stutter tone.
What should I try next? Is there anything I can say to voip.ms to point out what's lacking on their end?
ps: MWIEnable and X_VMWIEnable are enabled.
Despite what a voip.ms support agent may have told you, their VMWI is not working properly and it's not due to your Obi device.
When voip.ms put in the Cloudflare edge network to mitigate the DDoS attack, VMWI with voip.ms stopped working on all of my devices not just Obi devices. On the dslreports.com VoIP forum you'll find many members reporting the same problem.
I'm not a Voip.ms user but If you're using a 200/202 there may be a simple solution. Be sure X_MWISubscribe is checked. You'll find it under the sip parameters page. They might not have required registration before but may require it now in order for your device to receive MWI.
See post by Taoman in http://www.obitalk.com/forum/index.php?topic=18730.msg110361#msg110361
A user in the VoIP forum at DSLReports.com posted the following solution that worked for me.
QuoteTo sync it up, log into your voicemail box and delete all messages. If that doesn't work, call in and leave yourself a message, and then delete it.
To identify if the issue is specific to voip.ms, driving directions (https://mapquestdrivingdirections.app) consider testing with another VoIP service (if possible) to see if the stutter dial tone issue persists.