d>15012</td><td>GRPC</td><td>XDS and CA services (TLS, recommended for production use)</td><td>No</td></tr><tr><td>8080</td><td>HTTP</td><td>Debug interface (deprecated)</td><td>No</td></tr><tr><td>443</td><td>HTTPS</td><td>Webhooks</td><td>No</td></tr><tr><td>15014</td><td>HTTP</td><td>Control plane monitoring</td><td>No</td></tr></tbody></table><h2 id=server-first-protocols>Server First Protocols</h2><p>Some protocols are &ldquo;Server First&rdquo; protocols, which means the server will send the first byt