Tacodi — SIP & conference telephony (C++)

Engagement: Native C++ on client product team Stack: C++ · SIP · VoIP · conference bridges Domain: Live conferencing / telecom

Low-level C++ for SIP session lifecycle, PSTN/VoIP bridging, and network phone interfaces — the plumbing behind operator-facing conference products, not a web wrapper.

C++SIPVoIPConference bridgesNative telecom

Architecture

Session control vs media path

SIP signalling (INVITE/ACK/BYE, re-INVITE for hold/transfer) runs on dedicated threads separate from media mixing. Phone-interface adapters normalize hardware events into the same state machine conference cores use for soft clients.

Design decisions

Why native C++

Decision	Rejected	Why
Native C++ modules	Node/Java SIP stacks only	Latency + direct hardware/codec integration Tacodi already had
Explicit call FSM	Ad-hoc flags per feature	Conference transfers and hold states stay auditable under load
Interface adapters per phone type	One mega driver	Field deployments vary; adapters isolate vendor quirks

Reliability

Production constraints

Graceful teardown on partial network loss — no zombie SIP dialogs
Logging tied to Call-ID for field support correlation
Release cadence aligned to Tacodi field feedback, not agency milestones

Outcomes

Results

Production SIP and phone-interface modules in conferencing products
Proof of native C++ depth alongside Speechlogix telecom lineage
Comparable complexity to Trading Qt — different domain, same engineering bar

Tacodi programme. Details available under NDA.