What happens if you write a TCP stack in Python?
The idea that Python is so slow that it's confusing TCP sounds wrong to me. I think it's more likely that your packet capture scheme is slow. It looks like you're using scapy, which I assume is in turn using libpcap... which may be buffering (in high-performance network monitoring, the packet capture interface goes out of its way to buffer). Which is something you can turn off.About 13 years ago, I wrote my own programming language expressly for the purpose of implementing network stacks, and had a complete TCP in it; I didn't have this problem. But I do have this problem all the time when I write direct network code and forget about buffering.Similarly: "Python is so slow that Google reset the network connection" seems a bit unlikely too. Google, and TCP in general, deals with slower, less reliable senders than you. :)What's the time between your SYN and their SYN+ACK?