From the early GPRS roaming (IR.33) 
LTE EPC (IR.88/IR.65) 5G NR (NG.113 v11.0), telecom roaming has undergone a massive transformation. Let’s break it down with key highlights:
2G/3G Era (GPRS Roaming – IR.33)
APN format ..gprs
DNS-based GGSN selection 
GTP tunneling over GRX/IPX 
Basic QoS + TAP charging 
CS domain for Voice/SMS 
LTE/EPC Era (IR.88 / IR.65)
S8 Home-Routed roaming becomes standard 
Diameter replaces MAP/SS7 
VoLTE via IMS (S8HR / LBO) 
Policy control via S9 
GRX/IPX continues, IR.21 database 
5G NR Era (NG.113 v11.0)
Service-Based Architecture (SBA) 
SEPP security perimeter (N32) 
Network Slicing (S-NSSAI) 
DNN replaces APN + URSP policies 
IPUPS for N9 protection 
VoNR/VoIMS + SMS over NAS 
Key Evolution Drivers
2G → 3G: Packet data + basic roaming
3G → LTE: All-IP network + IMS voice
LTE → 5G: Cloud-native SBA + slicing + stronger security
Future: AI/ML optimization, Edge computing, and 6G prep 
Want to master Telecom Evolution and stay ahead in 5G/6G?
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