Paper review: <
IP Multicast Channels: Express Support for Large-scale Single-source
Reviewer: <Ryan Gehl>
- State the problem the paper is trying to solve.
The main problem this paper is trying to solve is the weakness of the
current IP multicase model to address the problems presented by emerging
large-scale multicast applications such as (1) no basis for charging, (2)
no access control, and (3) scaling difficulties.
- 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 work is the presentation of an extension to
IP multicast which supports the channel model and describes Explicitly
Requested Singles Source (EXPRESS) multicast.
- Summarize the (at most) 3 key main ideas (each in 1
(1) Express channels can be provided as a simple modification to the IP
multicast service model using a small portion of the class D address
(2) Based on the authors' estimates, it appears feasible for a router to
support millions of multicast channels without extraordinary investment in
either processing power or memory.
- 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 3 because it does present a straight-forward,
easy-to-implement solution to the growing problems in the area of
- 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.)
I felt like the authors methodology and assumptions were convincing. I do
think it is fair to say that large-scale multicast applications are almost
largely single-source and, as such, EXPRESS takes advantage of this
- What is the most important limitation of the approach?
The most important limitation to this approach is that if multi-source
multi-cast applications do become more prevelant, the additional
overhead from each channel that needs to be created may be significant.
- What lessons should researchers and builders take away from this
work. What (if any) questions does this work leave open?
One lesson I will take away from this work is that good solutions often
arise from applying new assumptions to old architectures.