Source note · Setting up FreePBX with a SIP trunk
For inbound traffic through NAT, the endpoint option force_rport, enabled by default, sends responses back to the source address of the request.
Checked 2026-09-25
- Vendor
- Asterisk Project
- Product
- Asterisk res_pjsip
- Subsystem
- NAT
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- Asterisk PJSIP Troubleshooting Guide — Sangoma / Asterisk Project · tier 2 current vendor documentation · ARGH! NAT!
Cite this note
APA
WarmTransfer. (2026, September 25). Setting up FreePBX with a SIP trunk: source note freepbx-sip-trunk-setup-force-rport-default. WarmTransfer. https://warmtransfer.net/knowledge/claims/freepbx-sip-trunk-setup-force-rport-default
BibTeX
@misc{warmtransfer-claim-freepbx-sip-trunk-setup-force-rport-default,
title = {Setting up FreePBX with a SIP trunk: source note freepbx-sip-trunk-setup-force-rport-default},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/freepbx-sip-trunk-setup-force-rport-default},
note = {Source note freepbx-sip-trunk-setup-force-rport-default, checked 2026-09-25}
}