Citation:
J.H. Saltzer, D.P. Reed, and D.D. Clark, "End-to-End Arguments in System
Design", ACM Transactions on Computer Systems, November 1984, pp. 277-288.

* Summary

A principle for guiding the placement of functionality among the modules 
in a distributed system is presented. The end-to-end argument suggests 
that functions placed at low levels of a system may be redundant or of 
little value when compared with the cost of providing them at this low level.

* End-to-End Argument

The function in question can completely and correctly be implemented only 
with the knowledge and help of the application standing at the endpoints 
of the comunication system. Therefore, providing that questioned function 
as a feature of the communications system itself is not possible. Sometimes 
an incomplete version of the function provided by the communications system 
may be useful as a performance enhancement.

* Keys to Decisions on End Points

1. Consider the "bad case" performance penalty of supplying the function 
   at each available level, choose the end point that minimizes the penalty 
   for the app
2. Placing functionality at a level that is shared by multiple higher-level 
   components causes all those components to incur the cost of providing 
   that functionality.
3. Will providing incomplete functionality at lower levels fool higher levels 
   into believing their requirements are being met?