TCP: How are the seq / ack numbers generated?

Question

I am currently working on a program which sniffs TCP packets being sent and received to and from a particular address. What I am trying to accomplish is replying with custom tai

Answer 1

Seems that the rest of the answers explained pretty much all about where to find detailed and official information about ACK's, namely TCP RFC

Here's a more practical and "easy understood" page that I found when I was doing similar implementations that may also help TCP Analysis - Section 2: Sequence & Acknowledgement Numbers