ther proxy.
This protocol extends TCP as follows:</p><ol><li>TCP client, as a first sequence of bytes, sends a magic byte string and a length prefixed payload.</li><li>TCP server, as a first sequence of bytes, sends a magic byte sequence and a length prefixed payload. These payloads
are protobuf encoded serialized metadata.</li><li>Client and server can write simultaneously and out of order. The extension filter in Envoy then does the further
processing in downstream and upstream until either the magic byte