Paper review: < Integrated Services in the Internet Architecture: an Overview [BCS94] >

Reviewer: <Ryan Gehl>

1. State the problem the paper is trying to solve.

The purpose of this paper (memo) is to discuss the proposed extension of the Internet architecture and protocols to provide integrated services (support for real-time and non-real-time services of IP).

2. State the main contribution of the paper: solving a new problem, proposing a new algorithm, or presenting a new evaluation (analysis). If a new problem, why was the problem important? Is the problem still important today? Will the problem be important tomorrow?  If a new algorithm or new evaluation (analysis), what are the improvements over previous algorithms or evaluations? How do they come up with the new algorithm or evaluation? 

The main contribution of this memo is to present an overview of the elements necessary to extend the Internet architecture to support integrated services.

3. Summarize the (at most) 3 key main ideas (each in 1 sentence.) 

(1) Real-time applications often do not work well across the Internet because of variable queueing delays and congestion losses.
(2) The real-time QoS infrastructure required for real-time applications must be designed from the beginning for multicastinging; simply generalizing from the unicast (point-to-point) case does not work.
(3) The proposed architectural extension is comprised of two elements: (1) an extended service model (IS model), which defines the externally visible behavior, and (2) a reference implementation framework.

4. Critique the main contribution
   • Rate the significance of the paper on a scale of 5 (breakthrough), 4 (significant contribution), 3 (modest contribution), 2 (incremental contribution), 1 (no contribution or negative contribution). Explain your rating in a sentence or two.

   I would rate this paper as a 4 because it clearly outlines the design space in which to build an extension to the existing Internet architecture which supports integrated services.

   • Rate how convincing the methodology is: how do the authors justify the solution approach or evaluation? Do the authors use arguments, analyses, experiments, simulations, or a combination of them? Do the claims and conclusions follow from the arguments, analyses or experiments? Are the assumptions realistic (at the time of the research)? Are the assumptions still valid today? Are the experiments well designed? Are there different experiments that would be more convincing? Are there other alternatives the authors should have considered? (And, of course, is the paper free of methodological errors.)

   As opposed to most papers which we've read for this course, this paper presents an outline of the design landscape for this problem as opposed to performing specific experiments, simulations, etc. The authors did implement a code package (CSZ) which realizes the services described in the memo.

   • What is the most important limitation of the approach?

   One limitation of the authors' approach is that I felt like the authors were forced to make some rigid assumptions in order to make this document limited in size. I wonder how relaxing some of the assumptions used by the authors would change the design space for this problem.

5. What lessons should researchers and builders take away from this work. What (if any) questions does this work leave open?

One lesson researchers should take away from this work is that one doesn't need to start entirely from scratch when building additional functionality into a system.