SCP (Service Communication Proxy)

In telecommunications, the SCP is a 5G Service-Based Architecture function that mediates HTTP/2 traffic between Network Functions, providing indirect communication, message routing, load balancing, and OAuth2 token handling. Because the SCP sits in the middle of all SBA flows, its hardening (mutual TLS, strict authorization, isolation) is critical to overall 5G security.

Categories: Core NetworkSecurity ControlsInternet and Routing

SCP in context

The mobile core is where subscriber sessions, mobility and policy live. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

Security controls in telecom span signaling firewalls (SS7/Diameter/GTP screening at the network edge), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both the packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36 and, in Europe, NIS2 sectoral rules.

To place SCP in the wider telecom-security picture, review Authorization, SCP Abuse, SBI, HTTP, Network Exposure Function (NEF) and OAuth2 in 5G Core.

Related terms

Equipment

5G SBA control (NRF, SCP, NSSF, BSF, NWDAF)

Articles in the P1 mobile network security guide

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