Voice Mail displayed on T48S?

[jolouis]

More importantly there have been major lawsuits in the past regarding any sort of Visual Voicemail type of setup. In the US the very concept of "visual voicemail" as you describe is patented by a troll who has in the past actively gone after anyone they can find. Apple ended up paying major royalties for the privilege of having their setup on the iOS. Similarly I believe FreePBX has a commercial module that will provide the XML to do it, but part of the fee for that module goes to paying the license of use.

So yes, you can build your own but depending on your location you may potentially get sued for it. This is one of the reasons many PBX vendors never bothered to implement/offer it (didn't want to pay licensing to somebody else).