56k modems/frame/ptp revisited (LONG)

13 people so far have asked me to post a summary to the list on this
subject, so here it is. I have included all responses I received,
with the name of the respondent at the top of their answer. Both
questions are included at the top for continuity purposes.

Question #1:

Anyone have a nice layman's terms explanation of the throughput/latency
differences between a 56k modem, a 56k leased line, and a 56k frame relay
circuit? This is assuming a "perfect" lab enviroment, ie. the modem
connects and sustains at maximum capability, the frame cloud is not
overloaded etc.. Please reply off list.

Question #2:

I've gotten lot's of responses on my original question, but I'm finding
perhaps I didn't ask the correct one. What I really need to know is what is
the real world effect of latency on throughput? I know that frame relay has
a higher latency than a point to point line, and that a point to point is
generally regarded as faster. Would someone mind explaining the specifics
of that relationship a little bit? Again, off list please, unless someone
thinks it's an appropriate topic for this list..