Capability bits on the browser-requested ingress SERVER_INFO frame.
The durable-ACK verdict travels here rather than on the handshake because
neither handshake carrier can deliver it to a browser: X-QWP-Durable-Ack
is unreadable from page JavaScript, and the questdb.qwp.durable-ack.v1
subprotocol cannot carry it either, since a browser fails the whole
connection when it offered a subprotocol and the 101 names none. The server
therefore echoes the subprotocol whenever it was offered -- confirming only
that it speaks the browser negotiation -- and reports the capability here.
Capability bits on the browser-requested ingress
SERVER_INFOframe.The durable-ACK verdict travels here rather than on the handshake because neither handshake carrier can deliver it to a browser:
X-QWP-Durable-Ackis unreadable from page JavaScript, and thequestdb.qwp.durable-ack.v1subprotocol cannot carry it either, since a browser fails the whole connection when it offered a subprotocol and the 101 names none. The server therefore echoes the subprotocol whenever it was offered -- confirming only that it speaks the browser negotiation -- and reports the capability here.