SIP - The Session Initiation Protocol (RFC 3261)
How SIP (RFC 3261) sets up, modifies, and tears down multimedia sessions using a text request/response model, its elements, layered design, transactions, dialogs, and security.
2026, Jul 20 —
RFC
Articles written directly from an IETF specification, following the RFC's own structure.
So far: the IPsec and IKE document roadmap (RFC 6071), the Session Initiation Protocol (RFC 3261), and the HMAC-based one-time password algorithm (RFC 4226).
3 posts
The IPsec and IKE Document Roadmap (RFC 6071)
A guided tour of RFC 6071, the roadmap that maps the sprawling IPsec and IKE RFC landscape - the seven document groups, IPsec-v2 vs v3, IKEv1 vs IKEv2, extensions, and crypto requirement levels.
2026, Jul 20 —
HOTP - An HMAC-Based One-Time Password Algorithm (RFC 4226)
How HOTP (RFC 4226) turns a shared secret and a counter into a 6-digit one-time password using HMAC-SHA-1 and dynamic truncation, with its security analysis, validation rules, and link to TOTP.
2026, Jul 20 —
