Integrating Two Live Networks Without Breaking the Customer Network integration · 5G · observability . 8 min read Large-scale network integrations are often described as a cutover problem. In reality, they are a behavioral problem. When two live mobile networks are stitched together, the hardest issues rarely come from radios or core elements in isolation. They emerge at the edges, where assumptions from one network collide with the operational realities of another. One of the earliest lessons during a nationwide integration effort was that roaming logic and native-network logic behave very differently under load. What works well for a roaming footprint can expose weaknesses quickly when millions of devices begin behaving as if the network is home. The issues that surfaced were not configuration gaps. They were assumption gaps. What surfaced only under live conditions None of the hardest problems appeared in lab testing. They appea...