dscp school...

i posted this to the ccie r&s forum on cln in response to a post where someone was having difficulty understanding dscp... i'm hoping someone attempts to refute it...

no takers yet...

here is a copy of the text larger... i wrote that in a couple of minutes from off the top of my head in the forum... this is the way dscp should be taught...


here is a chart that helped me make sense of it... the key is the class selector... the ip precedence simply follows the class selector, in other words it's the same for each cs... there are three af values per class selector... the classes are 0 to 7 or 8 total... class zero is zero, class 1 is decimal 8 and each selector increments by 8 there after... so 8x5 is 40 or class selector 5, whose decimal value is 40... the binary values simply follow the decimal values...  for each af value within each class selector the af values increment by 2 until they reach the next class selector... so class selector 2 = 16 and it's first af value is 18... the afs' themselves are described 1, 2 and 3for each class selector, so for class selector 2, they are 21 22 and 23, class selector 4 is 41, 42 and 43... see the chart below... ef breaks the pattern with a value of 46, but that's phone and you just remember that one...  6 and 7 are easy, just multiply by 8...