Multiplexing over one connection.
WHAT IT PROVIDES
Several concurrent streams over a single connection Binary framing rather than text Header compression, which matters because headers repeat Stream prioritisation
WHY HEADER COMPRESSION MATTERS
Requests carry substantial repeated headers, particularly cookies.
WHAT MULTIPLEXING ACHIEVES
Many requests in flight without opening many connections.
WHAT THAT MAKES OBSOLETE
Splitting assets across hostnames Combining files into bundles purely to reduce request count
WHY THOSE BECAME COUNTERPRODUCTIVE
Separate files cache independently, and the request cost is now low.
WHAT SERVER PUSH WAS
Sending resources before they were requested.
WHY IT WAS ABANDONED
It frequently sent what the client already had, wasting bandwidth.
WHAT REPLACED IT
Hints telling the client what to fetch early.
WHAT REMAINS A LIMITATION
A lost packet stalls all streams, because the transport delivers in order.
WHAT THAT MEANS
On lossy connections, the benefit is reduced.
WHY THAT MATTERS HERE
Mobile connections lose packets routinely.
