Your VICIdial Calls Are Getting Flagged as Spam — Here's the 13-Layer Fix

If you're running a VICIdial call center in 2026 and think STIR/SHAKEN is just another compliance checkbox, you're about to learn what a 50% drop in answer rates feels like. Here's the part nobody in the VICIdial community spells out clearly: STIR/SHAKEN compliance is necessary but nowhere near sufficient. Getting A-level attestation is Layer 1 of a 13-layer stack. Most operators stop there and wonder why their numbers get flagged as "Scam Likely" six days into a campaign. STIR/SHAKEN Authenticates Identity. That's It. STIR/SHAKEN is a cryptographic framework. Your SIP trunk provider's Authentication Service checks: do they know who you are, did they assign you this number, did the call originate on their network. If yes to all three, they generate a signed PASSporT token and inject it into the SIP header. The terminating carrier validates the signature and passes the result to analytics engines. Those engines — T-Mobile's Scam Shield (First Orion), AT&T's ActiveArmor (Hiya), Verizon's