I am looking at an application idea, it is for user to forward their mobile to a SIP number. a caller will call the mobile and it will be forward to this SIP number which answered by VAPI bot. Which type of Bot will load based on the number it is forwarding from. For SIP side, there is this Diversion header, so I wonder if this process is possible, assuming I can find a SIP trunk that support passing Diversion header over.

@sh.lim You can't rely on that. Diversion headers, depending on where your call is routed at origin, may or may not be available to VAPI to consume. Your idea is something 15 different people come to me every year to ask about - and every time the answer is identical. They start working on it, then 6 months in, and $50,000 of investment into numbers and intergrations and consulting, they realize the GTM is impossible to maintain and the ROI is too small - resulting in yet another "AI Voicemail Replacement Tool" failure.

hi! Thanks for the advice! I did similar solutions with ISDN + SIP in the 2000s but yes you are right, it is very carrier dependent and ROI is very small then. This is why I wonder if this is doable in a small scale and lower cost in this AI days. Thanks again!

@sh.lim Look, I'm an old-school Asterisk and Kamailio developer - look into the code, you will find my name in various places - trust me, if it would have been economical or had a sustainable Go To Market which made sense - people would have done it alrady.