Lab: Fix a failed registration

Debug Challenge

Now put your knowledge to the test with real failed registration traces. You will be presented with protocol captures showing registration failures at different points in the flow — authentication failures, security mode rejects, and subscription-related rejections. Your job is to identify exactly where the failure occurred, decode the 5GMM cause code, determine the root cause, and propose the correct fix. This simulates the troubleshooting work performed daily by NOC and SOC engineers in production 5G networks.