[telephony] Implement T-Mobile Visual VoiceMail Support ( new VMs generate blank text message from # 129 )

[Chris Gagnon]

version
maguro on phablet build #78

steps:
1. call SUT but do not pickup
2. leave a voice mail

Expected results:
missed call message shows up on phone.

Actual results:
129 message shows up on phone as a text message 2 times. 1 time with just the 129 number the other time with 129 as the number and this text:
//
VVM:SYNC:ev=NM;jd=94;c=4;t=v;s=16033036968;dt=11/02/2013 19:34 -0500;l=4

Additional info:
I am using t-mobile in the USA to call the SUT which is also using a t-mobile sim

Root Cause:

Messages from the number 129 on a phone using a T-Mobile SIM are for T-Mobile's Visual Voice Mail service. This is an operator specific voice mail application.

We will need to implement special SMS code to handle Visual Voice Mail if it becomes a required feature.

[Tony Espy (awe)]

@Chris

I'm not sure what you mean by "129 message"? Can you take a picture/screenshot? What number is the incoming message from? "129"?

I tried reproducing this by calling from my personal maguro to a maguro running image #79. As there's no VM associated with the AT&T SIM I'm using, I get an operator message instead of VM. The telephony-app correctly shows a "missed call" message.

Can you grab the syslog from the phone and attach it to the bug?

[Chris Gagnon (chris.gagnon)]

You have to leave a voicemail to get the 129 text message

[Chris Gagnon (chris.gagnon)]

I was able to reproduce this using google voice to leave a voicemail message the SUT which has a t-mobile SIM, on the #79 build

[Tony Espy (awe)]

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.

[Jamie Strandboge (jdstrand)]

I also see this after accessing TMobile voicemail (which due to bug #1268982 is quite difficult to access).