Hi kimzymes,
In the T1 transmission system these terms describe protocols and parameters: D4/SF & ESF = are the framing formats of the digital signal. D4 and SF are the same thing, stands for Superframe. ESF stands for Extended Superframe. AMI and B8ZS are line code parameters. AMI stands for Alternate Mark Inversion, in relation to framing only allows 56kb channel bandwidth. B8ZS stans for Bipolar Eight Zero Substitution, in relation to framing allows 64kb clear channel bandwidth.
There are many sources that provide reference and tutorial info on the T1 transmission system, one that comes to mind is BellCore/Telcordia. You might do a "Google" and find some good information. Also companies like Tellabs or Telecommunications Techniques Corp(TTC) in the past had some tutorial stuff.
Hope this helps!
....JIM....