Comment 7 for bug 1122584

First I tried reproducing this using the ATT test SIM I have. Unfortunately, this account doesn't have VM enabled. So although I ignored the call, the calling phone eventually got an operator message stating that no VM was configured for the called number. No 129 text messages were received on the called phone.

Next, I swapped my personal T-Mobile SIM into the test phone and tried the scenario again. Bingo.

After leaving a voicemail, I see both a missed call and an empty text message from # 129. Note, the times differ... this probably has something to do with the fact that we hard-code the system TZ. I'll enter a separate bug for the time mis-match.

Anyways, after each VM was left, I got another missed call and an empty text from 129. I did some research and found a bunch references to blank 129 messages being produced by T-Mobile's Visual Voice Mail service. Apparently if one T-Mobile subscriber calls another, they have an option to page the person using VVM too. I haven't investigated this option. Also, the message with the series of escaped characters from 129 is most likely a more complicated protocol message for T-Mobile's Visual VoiceMail.

I've changed the Importance to Wishlist, as this is a feature we'd need to implement if an OEM wanted to build a phone for T-Mobile.