STP vs DEA
The STP (Signalling Transfer Point) is the SS7 routing and screening node. The DEA (Diameter Edge Agent) is its LTE counterpart, sitting at the operator's Diameter boundary. Modern signaling firewalls terminate at whichever node applies.
| Attribute | STP | DEA |
|---|---|---|
| Protocol | SS7 (SCCP, TCAP, MAP, CAP) | Diameter |
| Screening spec | GSMA FS.11 | GSMA FS.19 |
| Placement | International SS7 border | LTE roaming border (S6a, S9) |
| Trust model | Point-code + GT screening | Origin-Host / Origin-Realm |
| Firewall role | FS.11 category enforcement | FS.19 application-level check |
Verdict
STP and DEA are structurally the same idea in different protocols. Deployments that harden the STP while leaving the DEA on defaults have simply migrated attacker interest to LTE — the same operator, the same subscribers, a fresher protocol.