Migrating FreePBX SIP Trunks from Chan_SIP to Chan_PJSIP Channel Drivers
by Provider Adminlast verified 2026-08-13
Overview
With chan_sip officially deprecated and removed in modern Asterisk releases, migrating FreePBX trunks to chan_pjsip is a critical maintenance task for administrators. This guide outlines the structural differences between legacy and modern channel drivers, provides mapping logic for trunk parameters, and details step-by-step procedures for transitioning both registration-based and IP-authenticated trunks. Readers will learn how to resolve port binding conflicts, configure PJSIP trunks cleanly in FreePBX, and execute seamless cutovers.
Key takeaways
- Understand the modular architecture of chan_pjsip compared to legacy chan_sip.
- Resolve UDP port binding conflicts when running dual channel drivers during migration.
- Map legacy chan_sip configuration key-value pairs directly to PJSIP equivalents.
- Configure both registration-based and IP-authenticated carrier trunks using FreePBX GUI.
- Verify trunk registration, endpoint matching, and media flow using Asterisk CLI diagnostic commands.
Prerequisites
- Administrative access to the FreePBX GUI and SSH access to the underlying OS.
- An existing active chan_sip trunk with stored carrier credentials or IP details.
- Knowledge of your carrier's SIP signaling requirements (e.g., Auth Username, SIP Server, Transport).
Full guide locked
The full guide sections and further reading are members-only.
This article contains 6 verified steps, 6 code blocks, and 0 additional screenshots.