As part of my SPDY work, I published an informal slide deck about the effect of TCPâ€™s slow start on HTTP performance.
- It has been known that TCPâ€™s slow start adversely effects performance in high-latency, high bandwidth networks for years.
- Increasing cwnd (reducing slow start) has been slow through standards due to concerns about internet collapse.
- But web servers and browsers have already worked around TCPâ€™s slow start by pummeling the net with excessive connections â€“ effectively making slow start irrelevant.
- If slow start has already been worked around, and the internet has not collapsed, it is time to seriously look at changing how slow start works so that we donâ€™t have to open 30 connections in order to have a low-latency transaction.
Feedback is welcome!