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SOME/IP

Automotive service-oriented middleware protocol for RPC-like and event-based communication over IP.

Status Examples Runtime example Source posture
draft-structure-only synthetic/passive docs-only atlas metadata plus public/tooling cross-checks

Identity

Automotive service-oriented middleware protocol for RPC-like and event-based communication over IP.

What This Protocol Teaches

  • SOME/IP is where vehicle communication starts looking like service software.
  • It teaches how to inspect service ID, method ID, message type without mistaking field extraction for meaning.
  • It keeps observer inference separate from system truth.

Operational Context

SOME/IP appears in automotive contexts and is modeled in the atlas at the application layer(s). The binder treats it as an inspection surface: what evidence appears, what timing matters, and what outside authority is required before assigning meaning.

Draft status

draft-structure-only: this is not yet a final-copy binder page. It has an atlas-grounded teaching hook and source notes, but still needs a stronger worked trace, page-specific ambiguity case, and reviewer-validated visual before promotion.

A Concrete Artifact

# synthetic SOME/IP message
service=0x1234 method=0x0421 client=0x0100 session=0x0002 len=8

Synthetic

Synthetic offline sample for explanation; not a real operational trace or live-system instruction.

Worked Decode

  1. Treat service=0x1234 and method=0x0421 as service-interface evidence in a synthetic message.
  2. client=0x0100 and session=0x0002 are correlation fields, not permanent ECU identity.
  3. len=8 bounds the message body but does not describe its application schema.
  4. Request, response, and event labels remain observed-message roles rather than instructions to invoke a service.

Field Layout / Anatomy

Element Shape Inspection meaning
service ID artifact-specific evidence Inspect with timing and source context before naming meaning.
method ID artifact-specific evidence Inspect with timing and source context before naming meaning.
message type artifact-specific evidence Inspect with timing and source context before naming meaning.
request/response/event artifact-specific evidence Inspect with timing and source context before naming meaning.
semantic authority external source Dictionary, profile, map, or integration document that turns evidence into named meaning.
timing context cadence / gap / slot / timestamp Freshness and ordering evidence for observer reconstruction.

Visual Model

flowchart LR raw["Raw evidence"] --> structure["Field structure"] structure --> timing["Timing / cadence"] timing --> authority["Semantic authority"] authority --> inference["Observer state hypothesis"]

Timing And Authority

Repeated service, method, client, and session fields can support correlation and cadence claims within an offline record. They do not establish which ECU owns the service, whether a response was accepted, or what the payload means.

Semantic authority

Service and method semantics come from the applicable AUTOSAR interface description and its provenance. Matching numeric IDs across captures is not enough to establish that the same deployed interface is present.

Failure And Ambiguity

  • Service and method IDs need ARXML or interface authority.
  • Client/session IDs correlate messages but do not prove ECU identity.
  • Observed request/response/event wording must stay passive and synthetic.

Observer Lesson

A passive observer can correlate synthetic request-, response-, and event-shaped records by visible header fields. It cannot prove endpoint identity, service availability, application acceptance, or physical state from those correlations.

Python Model

No current runtime example is claimed for this draft page. Keep reader claims at the artifact and source level until a separate implementation plan adds a tested model.

Local Teaching Notes

Simplification

The artifact and diagrams are synthetic teaching material. The page intentionally omits conformance timing tables, electrical design detail, proprietary configuration, and exhaustive standard behavior.

Source Confidence

Source confidence is medium for scope and terminology, with semantic claims limited to public metadata, public source notes, and synthetic teaching artifacts.

Source Notes

Field Value
Governance tier Tier 2 Field Note
Canonical source status yes
Public explainer status no
Open-source tool status yes
Sample-data status none listed; use synthetic teaching artifacts
Confidence medium
Citation specificity document-metadata-level
Canonical source(s) AUTOSAR Classic Platform standards (AUTOSAR; AUTOSAR Classic Platform; public-web; metadata-only)
Public explainer/tooling source(s) none listed in atlas
Open-source tool references Scapy automotive layers: automotive layer structure and packet inspection docs
Wireshark: Protocol dissectors and PCAP analysis

References

Public Sources