the window size field is of size 16 bits What is TCP Window Scaling? - GeeksforGeeksIn the TCP header, the window size field is of size 16 bits. Using this field TCP users (client or server) can advertise a maximum of 2 16 = 65536 bytes or 64 KiB as its buffer size to its other end-user.https://www.geeksforgeeks.org/what-is-tcp-window-scaling/