IPX vs GRX
GRX (GPRS Roaming Exchange) was the packet-only interconnect for 2G/3G data roaming. IPX (IP Exchange) is its multi-service successor — carrying GTP, Diameter, SIP, and eventually SBA. Most GRX carriers are now IPX carriers.
| Attribute | IPX | GRX |
|---|---|---|
| Traffic | GTP + Diameter + SIP + SBA | GTP data only |
| QoS | Contractual service classes | Best-effort |
| Standardization | GSMA IR.34 / IR.77 | GSMA IR.34 (legacy scope) |
| Security stance | Trusted intermediary — SEPP treats it as untrusted | Trusted intermediary |
| Modification role | PRINS signed modifications on N32-f | Passthrough |
Verdict
The IPX label is a business model, not a security guarantee. SEPP was designed specifically because the "trusted IPX" assumption no longer holds. Operators renewing IPX contracts should require published PRINS support, not just uptime SLAs.