[SR-Users] Kamailio E164 Normalisation

Hello, I have a requirement to normalise a number to an international E164 inside Kamailio. In my scenario I'm receiving a call from "a platform", and then making a call out to the same platform. I'm then adding some services to that call (e.g. recording it) on the way through. The problem is that sometimes the number I receive in the FROM field in the initial invite from "A platform" has 44 at the front, but no +. "A Platform" is then rejecting the call back in from myself, because the FROM field isn't formatted correctly. Scenario 1 - WORKS FINE - sometimes we see this. PSTN -> FROM:07700900000 -> A PLATFORM -> FROM:07700900000 -> ME Call Centre <- A PLATFORM <- FROM:07700900000 <- ME Scenario 2 DOES NOT WORK - sometimes we see this. PSTN -> FROM:447700900000 -> A PLATFORM -> FROM:447700900000 -> Aeriandi Call Centre <- A PLATFORM <- FROM:447700900000 <- Aeriandi Scenario 3 WORKS by fixing up the number by adding a + PSTN -> FROM:447700900000 -> A PLATFORM -> FROM: 447700900000 -> Aeriandi Call Centre <- A PLATFORM <- FROM:+447700900000 <- Aeriandi (ADD a PLUS) So I'm investigating if it's possible to fix up the number and add the + in Kamailio. Clearly I could detect if the number starts with 44 and change this to +44, but this seems very brittle (what about other international numbers) - it there a proper way to do this, or a standard module? Unfortunately asking "A platform" to send me the "FROM" in a consistent format is not an option. Many Thanks, Daniel