RADIUS backend TLS handshake timed out

Logged when TCP establishment succeeds but TLS negotiation with a RADIUS backend does not complete before the deadline. The peer_addr, tls_server_name, and handshake_timeout fields identify the peer and configured deadline.

Check backend TLS capacity, packet loss, and firewall behavior. Adjust handshake-timeout to allow normal negotiation while detecting failed peers promptly. A longer timeout delays failure detection and can delay fallback or a customer response.