E2 Application Protocol

Also known as: E2 Application Protocol

E2AP is the O-RAN application-layer protocol on the E2 interface that carries procedures between the Near-RT RIC and E2 nodes: RIC subscription, RIC indication, RIC control request, service update, and node configuration. It is transported over SCTP with mandatory TLS/IPsec and is the vehicle by which xApps observe and act on the RAN.

Categories: Radio Access NetworkProtocols and Standards

E2AP in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Telecom security is written into standards from 3GPP, GSMA, ETSI, IETF and ITU-T. Understanding which body owns which specification, and how the specs interlock (for example 3GPP TS 33.501 with GSMA FS.34 for 5G SBA security), is essential for both design and audit work.

To place E2AP in the wider telecom-security picture, review E2SM, TCP/IP, E2 Interface, Open Fronthaul, XnAP and X1.

Related terms

Related topic hubs

  • Open RAN Security O-RAN xApp/rApp, E2/A1/O1 interfaces and RIC security.
  • SEPP Security N32-c/N32-f, PRINS, JWE and OAuth 2.0 at the 5G roaming edge.
  • NAS Security Non-Access Stratum security, integrity and ciphering algorithms.

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.