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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.

Automated Compliance & Torture Test Suite

The library includes an automated 226-test suite featuring a dedicated compliance module located in tests/compliance/:

Test Suite File Standards Covered Key Verifications
tests/compliance/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/rfc4475_torture_tests.cpp RFC 4475 Official IETF torture test cases: wshort (minimal valid request), clnfrn (compact headers and mixed casing), foldhdr (multiline header folding with LWSP \r\n\t and \r\n), unkhdr (preservation of unknown/extension headers), multvia (array formatting for multiple Via headers), badact (rejection of unsupported method tokens), badlen (negative Content-Length rejection), and shortbuf (incomplete header section buffer handling).
tests/compliance/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/sdp_compliance_tests.cpp RFC 4566, RFC 8866, RFC 3264 Complete Session Description Protocol parsing: session-level lines (v=0, o=, s=, i=, u=, e=, p=, c=, t=), Offer/Answer direction attributes (sendrecv, sendonly, recvonly, inactive), WebRTC ICE/DTLS attributes (a=candidate, a=ice-ufrag, a=fingerprint:sha-256 ...), multiple SDP sessions (v=0 demarcation), and UNIX \n line endings.

Detailed Standard Verification Matrix

1. SIP Start Line Verification

  • 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

  • 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

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