SIP (Session Initiation Protocol)
The signaling protocol underlying most VoIP and cloud-dialer calls — the plumbing that connects dialers, carriers, and PSTN.
Full Definition
Session Initiation Protocol (SIP) is the IETF standard for initiating, maintaining, and terminating voice and video communication sessions over IP networks. In insurance, SIP is relevant because virtually all modern dialers (ReadyMode, ConvoSo, Five9) connect to the PSTN via SIP trunks provided by carriers (Bandwidth, Twilio, Telnyx, Peerless). SIP trunks are where STIR/SHAKEN attestation is applied — the originating carrier signs the caller ID at the SIP layer. SIP-level call quality (codec, jitter, packet loss) directly affects agent productivity; poor SIP routing shows up as dropped calls, one-way audio, or echo, and materially degrades contact and close rates. Agencies should monitor SIP MOS (Mean Opinion Score) alongside lead-level KPIs.
Example
An agency's contact rate on Monday drops 15%. Monitoring reveals a SIP trunk provider outage causing 22% call drops. The dialer fails over to a backup trunk and contact rate recovers within 40 minutes.
Related Terms
- Dialer (Predictive / Power / Manual) — Outbound calling software that accelerates agent dial volume — operating in predictive, power, progressive, or manual modes with very different TCPA risk profiles.
- STIR/SHAKEN — A caller ID authentication framework required of U.S. voice carriers to combat illegal spoofing and reduce robocalls.
- Call Recording — The capture and retention of agent-prospect phone conversations — required for Medicare sales (10-year retention) and heavily used for QA and TCPA defense.