The trick was to run many HTTP requests in parallel, using different subdomains so they wouldn't be subject to the browser limit on number of parallel connections to a domain, a dummy first request per subdomain so the interesting messages went over established persistent connections, and decoupling outbound from inbound messages to make a set of "short-long-polling" connections.
That resulted in real-time message throughput close to the game frame rate, bidirectional, and no connection setup latency per message, just the transmission latency even over TLS (SSL back then).
That resulted in real-time message throughput close to the game frame rate, bidirectional, and no connection setup latency per message, just the transmission latency even over TLS (SSL back then).