GTP-C and GTP-U Finally Separated Control from Subscriber Traffic
GTP made more sense once I stopped treating it as one protocol and separated tunnel-control signalling from the packets that actually carry user traffic.
GTP-U
N2 and N3 Helped Me Draw a 5G Call Path Without Hand-Waving
Separating N2 signalling from N3 user traffic made the gNB-to-core boundary much easier to troubleshoot.