What does the VARTA error `dial_failed` mean?

HTTP status: 502  ·  Type: provider_error

What it means

The telephony provider rejected or failed to place the dial.

What causes it

Raised when the LiveKit SIP participant creation call itself raises (backend/app/services/telephony.py), reached from POST /v1/calls with dial: true. The underlying provider exception is logged server-side, not returned to the caller.

What to do

Retry — this is typically transient carrier or provider trouble. Quote the request_id if it persists.