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TS 29.500 — 5G System; Technical Realization of Service Based Architecture; Stage 3⚓︎

Release: Rel 15 · Version assessed: 15.5.0 · Network: 5G · Applies to: AMF, SMF, UPF, NRF, UDSF, AUSF, UDM, UDR

Assessed from the AMF, SMF, UPF, NRF and UDSF implementations. The AUSF, UDM and UDR are assessed from their service configuration only (HTTP/2 with prior knowledge, TLS off by default).

Mandatory items: 40, of which 19 supported, 11 partially supported, 7 not supported and 3 not applicable. A further 5 clauses of the specification carry no conformance requirement and are not listed.

Mandatory items⚓︎

Ref. Item Status Support Remarks
4.1 NF services Mandatory Supported
4.2 Service based interfaces Mandatory Partial Namf, Nsmf, Nudm, Nnrf, Nausf, Nudr and Nudsf are used; Npcf, Nnssf, Nnef, Nsmsf, Nlmf, Nchf and Nnwdaf are not.
4.3.1 NF service framework: general Mandatory Partial NF registration, discovery and access tokens through the NRF are used; indirect communication through an SCP is not.
4.3.2 NF service advertisement URI Mandatory Supported Service URIs are advertised in the NF profile registered with the NRF.
5.1 Protocol stack overview Mandatory Partial HTTP/2 over TCP with JSON payloads; TLS is available on a dedicated listener and is off by default.
5.2.1 HTTP/2 protocol: general Mandatory Supported HTTP/2 with prior knowledge (cleartext) on every service-based interface.
5.2.2.1 HTTP standard headers: general Mandatory Supported
5.2.2.2 Mandatory to support HTTP standard headers Mandatory Partial Content-Type, Content-Length, Location and Accept are used; Cache-Control, If-Modified-Since, If-None-Match, If-Match and Via are not handled.
5.2.3.1 HTTP custom headers: general Mandatory Not supported No 3gpp-Sbi custom header is read or written by any network function.
5.2.3.2.1 Mandatory to support custom headers: general Mandatory Not supported No 3gpp-Sbi custom header is read or written by any network function.
5.2.3.2.2 3gpp-Sbi-Message-Priority Mandatory Not supported Not read or written.
5.2.3.2.3 3gpp-Sbi-Callback Mandatory Not supported Not written on notifications.
5.2.4 HTTP error handling Mandatory Supported ProblemDetails bodies on 4xx and 5xx responses.
5.2.6 HTTP/2 connection management Mandatory Supported
5.2.7.1 HTTP status codes: general Mandatory Partial 3xx responses are not followed; they are treated as errors.
5.2.7.2 NF as HTTP server Mandatory Supported
5.2.7.3 NF as HTTP client Mandatory Partial 3xx, 4xx and 5xx responses end the request and start error handling; no redirection is followed.
5.2.8 HTTP/2 request retries Mandatory Supported The SMF retries with exponential back-off (eight attempts, 1 s to 16 s).
5.2.9 Handling of unsupported query parameters Mandatory Supported Unsupported query parameters are ignored.
5.3 Transport protocol Mandatory Partial TCP; TLS is available on a dedicated HTTPS listener and is off by default.
5.4 Serialization protocol (JSON) Mandatory Supported
5.5 Interface definition language (OpenAPI) Mandatory Supported
6.1.1 Routing mechanisms: general Mandatory Supported
6.1.2 Identifying a target resource Mandatory Supported
6.1.3 Connecting inbound Mandatory Partial Direct connections between network functions of one PLMN; no inter-PLMN connection.
6.1.4.1 Pseudo-header setting: general Mandatory Supported
6.1.4.2 Routing within a PLMN Mandatory Supported Peers are addressed by configured URIs; no SCP.
6.1.4.3 Routing across PLMN Mandatory Not applicable (Visited-network roaming role)
6.1.5 Host header Mandatory Supported
6.2 Server-initiated communication (notifications) Mandatory Supported
6.4.2 HTTP status code 503 Service Unavailable Mandatory Supported
6.4.3 HTTP status code 429 Too Many Requests Mandatory Supported
6.6.1 Extensibility mechanisms: general Mandatory Not supported The supportedFeatures attribute is not negotiated.
6.6.2 Feature negotiation Mandatory Not supported The supportedFeatures attribute is not negotiated.
6.7.1 Security mechanisms: general Mandatory Partial Assessed per sub-clause.
6.7.2 Transport layer security protection of messages Mandatory Partial TLS is available on a dedicated HTTPS listener and is off by default; the service-based interfaces run inside the site's network.
6.7.3 Authorization of NF service access Mandatory Partial OAuth 2.0 client credentials with access tokens issued by the NRF; the AMF and NRF validate tokens, the SMF does not.
6.7.4.1 Application layer security across PLMN: general Mandatory Not applicable (Visited-network roaming role)
6.7.4.2 N32 procedures Mandatory Not applicable (Visited-network roaming role)
Annex B 3gpp-Sbi-Callback types (normative) Mandatory Not supported The 3gpp-Sbi-Callback header is not written.

Optional items⚓︎

The specification leaves these 18 items to the implementation; 4 are supported or partially supported. An item marked Not applicable belongs to an area the platform does not provide, named in the Support column. Expand for the full list.

18 optional items
Ref. Item Support Remarks
6.3 Load control Not supported
6.4.1 Overload control: general Partial 503 and 429 are used; no other overload mechanism.
6.4.4 HTTP status code 307 Temporary Redirect Not supported
6.5.1 Support of stateless NFs: general Supported UE contexts are kept in the UDSF.
6.5.2 Stateless AMFs Partial Assessed per sub-clause.
6.5.2.1 Stateless AMFs: general Partial Contexts are stored in the UDSF; planned removal of an AMF is not supported.
6.5.2.2 AMF as service consumer Not supported
6.5.2.3 AMF as service producer Not supported
6.6.3 Vendor-specific extensions Not supported
6.6.4 Extensibility for query parameters Not supported
6.8.1 SBI message priority mechanism: general Not supported
6.8.2 Message level priority Not supported
6.8.3 Stream priority Not supported
6.8.5 HTTP/2 client behaviour Not supported
6.8.6 HTTP/2 server behaviour Not supported
6.8.8 DSCP marking of messages Not supported
6.9.1 Discovering the communication options supported by a target: general Not supported
6.9.2.2 Content-encodings supported in HTTP requests Not supported

Assessed 2026-09-17 against TS 29.500 version 15.5.0.