PBX & VoIP Fundamentals — Course

Two-week self-paced curriculum: telephony, SIP/RTP, PBX, and WebRTC.

Week 1

Foundations: PBX, telephony, SIP, RTP, first PBX lab

Week 2

Advanced: NAT/ICE, routing, trunks, security/SBCs, IVR, WebRTC

SIP Messages — Basic Call Flow

This diagram summarizes REGISTER, INVITE/200/ACK, RTP, and BYE.

SIP call flow: REGISTER, INVITE, 180 Ringing, 200 OK, ACK, RTP, BYE — UAC ↔ Proxy/SBC ↔ UAS sequence.

PBX & VoIP Fundamentals