Not another guess: installed coturn locally (apt-get install coturn) and
ran the actual server + turnutils_uclient against it to verify this
before shipping, since the last two rounds shipped based on reading the
usage text alone and both turned out incomplete.
-e 127.0.0.1 satisfies turnutils_uclient's "-e or -y required" check, but
then fails allocation with "channel bind: error 403 (Forbidden IP)" —
services/coturn.sh never sets --allow-loopback-peers, so loopback as a
peer address is correctly rejected by a real coturn instance, and the
previous fix's own comment about "loopback is always reachable" missed
that reachable and permitted aren't the same thing.
-y ("client-to-client") sidesteps this: it negotiates both ends of a real
relay through the server itself, needs no separate peer address, and
works fine over loopback. Verified directly against a real local
instance: exits 0 with real packet-loss/RTT stats on valid credentials,
and correctly fails ("Cannot complete Allocation", exit 255) on a wrong
password — so it's still a meaningful pass/fail, not just "didn't crash."
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn