IOT

Interoperability testing is the reality check that conformance can't give you. Conformance proves each box obeys the spec on its own; IOT puts boxes from different vendors together — a handset chipset against vendor A's gNB, vendor A's gNB against vendor B's core — and checks they actually cooperate under realistic conditions. The interesting failures live exactly here, because specs leave room for interpretation, optional features get implemented differently, and timing or sequence edge cases only surface when two independent implementations meet.

This is bread-and-butter work in multi-vendor networks and a big deal for open RAN, where the entire premise is mixing vendors at interfaces that used to be a single supplier's private business. Plugfests and dedicated IOT campaigns exist precisely to flush out these mismatches before they reach live traffic. One naming caution: in this glossary "IOT" means Inter-Operability Testing — don't confuse it with IoT, the Internet of Things. Same letters, completely different topic.