Twilio Elastic SIP Trunking has a per-trunk Symmetric RTP setting. When enabled, Twilio latches onto the incoming RTP stream and sends RTP back to where it came from, not to the SDP-negotiated address. Twilio offers this for customers behind a non-SIP-aware NAT whose SDP carries a private IP.

Checked 2026-09-24

Twilio is able to resolve this by latching onto the incoming RTP media stream and sending RTP towards that destination by enabling Symmetric RTP.
Vendor
Twilio
Product
Elastic SIP Trunking
Subsystem
symmetric RTP
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-24
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). One-way and no-way audio diagnosis: source note one-way-audio-twilio-symmetric-rtp. WarmTransfer. https://warmtransfer.net/knowledge/claims/one-way-audio-twilio-symmetric-rtp

BibTeX

@misc{warmtransfer-claim-one-way-audio-twilio-symmetric-rtp,
  title  = {One-way and no-way audio diagnosis: source note one-way-audio-twilio-symmetric-rtp},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/one-way-audio-twilio-symmetric-rtp},
  note   = {Source note one-way-audio-twilio-symmetric-rtp, checked 2026-09-24}
}

Read in context