Protocols
Protocols we speak.
A reference for the 3GPP protocols and interfaces dflux Runik puts on the wire — each with its specification. We list what we use; we don't invent coverage percentages.
By protocol
Control plane, user plane, SBI.
The wire-level surface Runik drives, organized by protocol and 3GPP reference point.
NGAP
3GPP TS 38.413N2 — gNB ↔ AMF
over SCTP (RFC 4960)
NG Application Protocol carries control signaling between the gNB and the AMF — NG setup, UE context management, and PDU-session resource setup. NAS messages ride inside it.
NAS (5GS)
3GPP TS 24.501N1 — UE ↔ AMF
tunneled in NGAP over N2
Non-Access Stratum signaling between the UE and the core: registration, authentication (5G-AKA), security mode, PDU-session NAS, and SMS over NAS. It has no transport of its own and is carried inside NGAP.
PFCP
3GPP TS 29.244N4 — SMF ↔ UPF
over UDP
Packet Forwarding Control Protocol — how the SMF programs the UPF: node association and session establishment, modification, and deletion, plus the forwarding rules for UE packets. On Runik, PFCP is licensed — not on the unsigned community binary.
GTP-U
3GPP TS 29.281N3 — gNB ↔ UPF
over UDP
GPRS Tunneling Protocol, user plane — encapsulates UE user-plane packets between the gNB and the UPF. dflux Runik generates GTP-U user-plane traffic after PDU session setup.
User-plane data (N6)
IP over TUNN6 — UPF ↔ data network
userspace datapath
The data-network side of the UPF. Decapsulated UE traffic is forwarded as plain IP, not a 3GPP-specific protocol.
SBI over HTTP/2
3GPP TS 29.500-seriesService-based interfaces
HTTP/2 (h2c by default), JSON
The 5G service-based interfaces between NFs (Namf, Nsmf, Nausf, Nudm, Npcf, Nnrf). NF service framework is TS 29.500; per-NF services live in the 29.5xx specifications (see below).
Diameter
RFC 67334G interworking — S6a / Gx / Rx
over TCP or SCTP
Diameter base protocol with the S6a, Gx, and Rx application filters. dflux Runik exercises a vendor's policy plane over Diameter.
S6a / Gx / Rx map to 3GPP TS 29.272 / 29.212 / 29.214 respectively.
SBI services
Service-based interfaces, by NF.
The per-NF service-based interfaces carried over SBI HTTP/2, each defined by its own 3GPP specification.
NFServiceSpec
NRFNnrf_NFManagement / NFDiscovery / AccessTokenTS 29.510
AMFNamf_CommunicationTS 29.518
SMFNsmf_PDUSessionTS 29.502
AUSFNausf_UEAuthenticationTS 29.509
UDMNudm_SDM / UECM / UEAUTS 29.503
PCFNpcf_AMPolicyControl / SMPolicyControlTS 29.514
SMSFNsmsf_SMServiceTS 29.540
Which tool uses what
Protocols Runik drives.
A used / not-used map — not a coverage score. Runik drives procedures as a tester. PFCP on Runik is licensed.
SBI here means the HTTP/2 service framework (TS 29.500-series); per-NF service specs are listed above. Diameter covers the S6a / Gx / Rx application filters over RFC 6733. PFCP is licensed on Runik and is not on the unsigned community binary.
Need a specific interface?
Tell us what you need to test.
Looking for a protocol, procedure, or interface that isn't listed? Tell us what you're building and we'll get back to you.