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SIP & SDP Standards Compliance

sip2json is designed and validated against official IETF Session Initiation Protocol (SIP) and Session Description Protocol (SDP) standards.

Standards Conformance Architecture

graph TD
    subgraph Core ["SIP Core Standards"]
        A["RFC 3261: Base Protocol Grammar"]
        B["RFC 3261 §20: Compact Header Abbreviations"]
        C["RFC 3261 §7.3.1: Case-Insensitive Normalization"]
    end
    subgraph Torture ["IETF RFC 4475 Torture Corpus"]
        D["50 Bit-Exact Test Cases (.dat Fixtures)"]
        E["Escaping, Long Fields & Character Sets"]
        F["Malformed Frame Safety & Rejection"]
    end
    subgraph SDP ["SDP & WebRTC Specifications"]
        G["RFC 4566 / RFC 8866 Session Syntax"]
        H["RFC 3264 Offer / Answer Model"]
        I["RFC 8829 / RFC 8839 WebRTC BUNDLE, ICE & DTLS"]
    end
    Core --> Torture
    Torture --> SDP

Automated Compliance & Torture Test Suite

The library includes an automated compliance module located in tests/compliance/. For a complete section-by-section mapping of all test runner files, line numbers, sample fixtures, and direct links to official IETF standard specifications, see Test Suite Sources & Standards Reference.

Test Suite File Standards Covered Key Verifications
tests/compliance/src/rfc3261_compliance_tests.cpp RFC 3261 Request line parsing for 14 RFC methods (INVITE, ACK, OPTIONS, BYE, CANCEL, REGISTER, SUBSCRIBE, NOTIFY, REFER, PUBLISH, UPDATE, PRACK, INFO, MESSAGE), status line classes (1xx-6xx), case-insensitive header key canonicalization, compact header field abbreviations (v, f, t, i, c, l, m, s, k, e), and body framing.
tests/compliance/src/rfc4475_torture_tests.cpp RFC 4475 All 50 official bit-exact IETF torture test cases (.dat files): wsinv.dat (§3.1.1.1: minimal valid request), multi01.dat (§3.1.1.2: character set variations), esc01.dat/escnull.dat (§3.1.1.3/4: URI escaping & escaped nulls), lwsdisp.dat (§3.1.1.6: no LWS before <), longreq.dat (§3.1.1.7: long header values), unreason.dat/noreason.dat (§3.1.1.12/13: non-ASCII & empty reason phrases), ncl.dat (§3.1.2.3: negative Content-Length), badvers.dat (§3.1.2.16: invalid protocol version), mpart01.dat (§3.1.1.11: multipart MIME rejection), and shortbuf (§3.1.2.5: incomplete buffer handling).
tests/compliance/src/sip_certification_suite.cpp RFC 3261, 3262, 6665, 3515, 3903 End-to-end certification for SIP Core (§7.1, §7.2, §7.3), PRACK reliability (RAck/RSeq), Event Notifications (Event/Subscription-State), Call Transfer (Refer-To), and Event Publication (SIP-ETag).
tests/compliance/src/sdp_compliance_tests.cpp RFC 4566, 8866, 3264, 8829, 8839 Complete Session Description Protocol parsing: RFC 4566 Section 9 reference session description, Offer/Answer direction attributes (sendrecv, sendonly, recvonly, inactive), WebRTC BUNDLE media grouping (a=group:BUNDLE), ICE candidates (a=candidate), ICE credentials (a=ice-ufrag, a=ice-pwd), DTLS fingerprints (a=fingerprint:sha-256 ...), RTCP multiplexing (a=rtcp-mux), multiple SDP sessions (v=0 demarcation), and UNIX \n line endings.

Detailed Standard Verification Matrix

1. SIP Start Line Verification (RFC 3261 §7.1 & §7.2)

  • Supported Methods: INVITE, ACK, OPTIONS, BYE, CANCEL, REGISTER, SUBSCRIBE, NOTIFY, REFER, PUBLISH, UPDATE, PRACK, INFO, MESSAGE.
  • Method Rejection: Non-standard or custom method tokens (e.g. BENCHMARK, CUSTOM) are rejected during startline matching and serialization validation.
  • Protocol Version: Rejects unsupported protocol versions (SIP/1.0, SIP/3.0, HTTP/1.1), enforcing strict SIP/2.0 compliance.

2. Header Field Processing (RFC 3261 §7.3.1 & §20)

  • Case-Insensitive Normalization: Normalizes incoming header field names (vIa, fRoM, cALL-id, cONTENT-lENGTH) to canonical Pascal-Kebab-Case keys (Via, From, Call-ID, Content-Length).
  • Compact Form Expansion: Automatically maps single-letter abbreviations (v, f, t, i, c, l, m, s, k, e) to their canonical header field equivalents.
  • Multiline Header Folding: Unfolds multiline header values continuation lines beginning with LWSP (\r\n and \r\n\t) per RFC 3261 §7.3.1.
  • Multiple Headers: Preserves multiple header occurrences (Via, Record-Route, Route, Accept) as JSON arrays.

3. SDP Body Processing (RFC 4566, RFC 8866, RFC 3264, WebRTC RFC 8829 / 8839)

  • Format Compliance: Parses SDP session descriptions into structured /b/sdp JSON objects per RFC 4566 and RFC 8866.
  • WebRTC Extensions: Full support for BUNDLE media grouping (a=group:BUNDLE), ICE credentials (ice-ufrag, ice-pwd), candidate lines (a=candidate), and DTLS fingerprint attributes (a=fingerprint:sha-256 ...).
  • Line Ending Flexibility: Seamlessly parses SDP payloads formatted with internet CRLF (\r\n) or UNIX LF (\n).