FLUTE and its building blocks are specified by the IETF. 3GPP SA4 profiles FLUTE for MBMS download in TS 26.346 and for the MBS Object Distribution Method in TS 26.517. This page lists the documents and which profile uses which.
The page follows the latest Release 19 issues: TS 26.346 V19.3.0 and TS 26.517 V19.3.0.
At a glance
- FLUTE version 1: RFC 3926, with ALC (RFC 3450) and LCT (RFC 3451). Both 3GPP profiles refer to it. FLUTE version 2 (RFC 6726, with RFC 5775 and RFC 5651) is current IETF text, not used by them.
- FEC schemes: Compact No-Code (RFC 3695) in every profile; Raptor (RFC 5053) mandatory to support by the UE in MBMS download and in the MBMS Download Profile, which MBS Object Distribution follows.
- Requirement by requirement: FLUTE: what each profile requires lists every requirement by feature, with the clause that changes it in each profile and release.
- 3GPP profiles: MBMS download in TS 26.346 clause 7.2 and annex L.4; MBS Object Distribution in TS 26.517 clause 6.2, which conforms to the MBMS Download Profile.
- Also tracked: ROUTE (RFC 9223), not used by either 3GPP profile, and CMMF (ETSI TS 103 973 V1.2.2), which has its own page.
Which profile uses which
A tick means the profile requires the document, directly or through the profile it builds on.
| Document | Used for | Unprofiled FLUTE | MBMS download | MBS Object Distribution |
|---|---|---|---|---|
| RFC 3926 | FLUTE version 1 | ✓ | ✓ | ✓ |
| RFC 3450 | ALC | ✓ | ✓ | ✓ |
| RFC 3451 | LCT | ✓ | ✓ | ✓ |
| RFC 3695 | Compact No-Code FEC (FEC Encoding ID 0) | ✓ | ✓ | ✓ |
| RFC 5053 | Raptor FEC (FEC Encoding ID 1) | — | ✓ | ✓ |
| RFC 1952 | GZip content encoding | — | ✓ | ✓ |
| TS 26.346, clause 7.2 and annex L.4 | FLUTE usage for MBMS download; the MBMS Download Profile | — | ✓ | ✓ |
| TS 26.346, annex L.6 | Profiled FLUTE FDT schema | — | — | ✓ |
| TS 26.517, clause 6.2 | FLUTE for the Object Distribution Method | — | — | ✓ |
- Unprofiled FLUTE: RFC 3926 builds on RFC 3450 and RFC 3451, and refers to RFC 3695 for FEC Encoding ID 0. It allows content encoding, GZip among others, without requiring it.
- MBMS download: clients and servers implement RFC 3926 with the ALC and LCT features it inherits. Compact No-Code is supported, every UE decodes Raptor, and UEs support GZip decoding.
- MBS Object Distribution: the MBS Distribution Session conforms to the MBMS Download Profile, and the MBSTF uses the profiled FDT schema of annex L.6.
What each profile requires, row by row, is in the Technical Analysis.
Specifications
29 of 29 specifications
| Specification | Title | Layer |
|---|---|---|
| RFC 3926 | FLUTE - File Delivery over Unidirectional TransportCore protocol, FDT, version 1 | IETF (normative) |
| RFC 3450 | Asynchronous Layered Coding (ALC) Protocol InstantiationTransport building block | IETF (normative) |
| RFC 3451 | Layered Coding Transport (LCT) Building BlockHeader format, TSI/TOI, Close Session/Object flags | IETF (normative) |
| RFC 5052 | Forward Error Correction (FEC) Building BlockFEC OTI, EXT_FTI, source block partitioning | IETF (normative) |
| RFC 3695 | Compact No-Code FEC schemeFEC Encoding ID 0 | IETF (normative) |
| RFC 5053 | Raptor FEC schemeFEC Encoding ID 1; the MBMS FEC scheme per TS 26.346 clause 7.2.12 and Annex B | IETF (normative) |
| RFC 1952 | GZIP file formatContent encoding of files for transport (TS 26.346 clause 7.2.5) | IETF (normative) |
| RFC 4607 | Source-Specific Multicast (SSM)Reception filtered on the announced source address | IETF (normative) |
| RFC 4570 | SDP Source FiltersHow SSM sources are announced (SDP handled by consuming applications) | IETF (normative) |
| RFC 5905 | Network Time ProtocolTime base for FDT and Cache-Control expiry values | IETF (normative) |
| RFC 6726 | FLUTE version 2Revises RFC 3926; not the 3GPP-mandated profile | IETF (reference only) |
| RFC 5651 | LCT (revised)Revises RFC 3451 | IETF (reference only) |
| RFC 5775 | ALC (revised)Revises RFC 3450 | IETF (reference only) |
| RFC 6330 | RaptorQ FEC schemeFEC Encoding ID 6; not part of the TS 26.346 FEC scheme set | IETF (reference only) |
| RFC 9223 | Real-Time Transport Object Delivery over Unidirectional Transport (ROUTE)Informational, independent submission (April 2022); not used by TS 26.346 or TS 26.517 | IETF (reference only) |
| RFC 6968 | FCAST object deliveryTransport building block | IETF (reference only) |
| RFC 8216 | HTTP Live Streaming (HLS)Adaptive streaming format carried over these transports | IETF (normative) |
| TS 26.346 | Multimedia Broadcast/Multicast Service (MBMS); Protocols and codecsLatest Release 19 issue: V19.3.0. The central specification for FLUTE-based delivery. Clause 7.2 covers FLUTE usage for MBMS download (header specializations, FDT schema and 3GPP FDT extensions, FEC schemes, content encoding); clause 7.2.12 and Annex B the MBMS FEC scheme (Raptor, RFC 5053); clause 7.3 SDP for the download delivery method; clause 9 associated delivery procedures, file repair and reception reporting; Annex L the MBMS Download Profile and User Service profiles. | 3GPP |
| TS 26.347 | MBMS URLs and APIsMBMS client interface towards applications (consumer scope) | 3GPP |
| TS 23.246 | MBMS; Architecture and functional descriptionContext | 3GPP |
| TS 26.517 | 5G Multicast-Broadcast User Services; Protocols and FormatsLatest Release 19 issue: V19.3.0. Clause 6.2 defines the Object Distribution Method over FLUTE and binds it to the MBMS Download Profile of TS 26.346 | 3GPP |
| TS 26.502 | 5G MBS; User service architecture | 3GPP |
| TS 23.247 | Architectural enhancements for 5G MBSDefines the N3mb/GTP-U transport context served by rt-libflute's UDP tunnel mode | 3GPP |
| TS 29.581 | 5G System; MBSTF servicesThe service APIs of rt-mbs-transport-function, the main 5G MBS consumer of rt-libflute | 3GPP |
| TS 26.247 | 3GP-DASH; Transparent end-to-end packet-switched streaming serviceThe 3GPP DASH profile carried over these transports | 3GPP |
| ISO/IEC 23009-1 | Dynamic Adaptive Streaming over HTTP (DASH)Media presentation and segment formats | Media formats |
| ISO/IEC 23000-19 | Common Media Application Format (CMAF)Segmented media container | Media formats |
| ETSI TS 103 285 | DVB-DASHThe DVB DASH profile | Media formats |
| ETSI TS 103 973 | Coded Multisource Media Format (CMMF) for Content Distribution and DeliveryV1.2.2 (2026-05); a container for coded media from more than one source, with content delivery protocol instantiations in annex D | Multisource delivery |
For the release-by-release history, see Standards Evolution.
Sources for this page
- Which profile uses which: RFC 3926, section 5.1.2.1 and Normative References [2], [3], [7] and [17]; TS 26.346 V19.3.0, clauses 7.2.0, 7.2.2, 7.2.5, L.4.7 and L.6.1; TS 26.517 V19.3.0, clause 6.2.1.
- FLUTE version 2: RFC 6726, section 11.1.
- ROUTE: RFC 9223, header and section 1.1.