Hi Team, we just spinned up secure trunking following https://docs.livekit.io/telephony/features/secure-trunking/#configure-secure-trunking-for-sip-calls with Telnyx, but I'm not able to perform transfer calls. Is this a known limitation or is there a workaround ? Thx!

You need to work with Telnyx to enable that for you. I think they are strict with their transfer policies.

Ty! I'll reach out to them. In the meantime, i found this documentation on their website https://developers.telnyx.com/docs/voice/sip-trunking/livekit-configuration-guide#4-set-custom-headers-when-sending-sip-invites but it mentions a 'headers_to_attributes' field on the livekit outbound trunk that isnt a valid option (at least web ui doesnt let me add it )

Oh, so the issue is isolated to SIP over TLS but works otherwise?

right

Do you have a call ID where it failed?

Sure. this one from half an hour ago https://cloud.livekit.io/projects/p_2ettdbc3zkw/telephony/SCL_XB7TSFmMApUG/inbound

We looked at the call id you shared and that transfer looks like it worked.

Right, but no outbound call gets triggered.