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Showing posts from March, 2009

TCP Window Scale

One of the overlooked subjects especially when it come to the CCIE RS is the real deep knowledge and understanding of TCP, the one subject from the scope of TCP that I would like to pass to you readers is the concept of Window Scaling. Why do we need window scaling or what the hell is it?! First may be lets start with the why, I do not know about you guys but when I am buying something I expect to utilize it fully and not half way, and the same goes to my Internet line if I buy 10Mbps pipe I do not want to utilize only 5Mbps. So What is Window Scaling and how can he help us better utilize our pipe?! Window Scaling is an optional enhancement that allows us to extend our window size so you say wait why do I need to extend my window size? Well normally the window size is 16 bit with a max size of 64K byte and when you are talking about a in your LAN delay (1ms avg) that is more then enough for just above 500Mbps but when we are over the WAN we start experiencing some delays the amoun…