TCP Headers: Window Size, Checksum & More

Window Size

Remember the ‘buffer’ we discussed in the last lesson? Well, the window size is essentially the amount of available space in that buffer. TCP at the receiving end buffers incoming data that has not been processed yet by the overlaying application. The amount of available space in this buffer is specified by the window size.

The window size can be up to 2 bytes in size hence, the numerical range of the window size is from $2^0\to2^{16}-1$ ...