HTTP + Callbacks
Seems an unlikely candidate
- Adapted to low-latency, sink-initiated, end-to-end, reliable delivery on a one-to-one basis
Two relevant features widen its range
- HTTP syntax already affords relaying a request and response along a chain of proxy servers (incl. caching)
- Can have HTTP client and server at any Internet node
“Symmetric” HTTP client-server pair allows range of latency, initiation, intermediation, and delivery