• Different hardware between now and then. • Modify the implementation of TCP to improve its performance • DCTCP (Data Center TCP) • MPTCP (Multi Path TCP) • Google BBR (Modify Congestion Control Algorithm) • New Protocol •  • Re-architecting datacenter networks and stacks for low latency and high performance
• Sends the packet to its receive queue (RX) • System (kernel) needs to know the packet is coming and pass the data to a allocated buffer. • Polling/Interrupt • Allocate skb_buff for packet • Copy the data to user-space • Free the skb_buff
in server. • We can dedicated some CPU to handle network packets. • Polling mode • Zero-Copy • Copy to the user-space iff the application needs to modify it. • Sendfile(…) • UIO (User Space I/O) • mmap (memory mapping)
than the system L1/L2/L3 cache • Too many cache miss (increate latency) • A Single Application unlikely can congest the network bandwidth. • Authors says. • 20-30 GBs for data buffer 4KB • 2-4 GBs for data buffer > 4MB • Too many cache miss.