Subject: [decade] WG Review of draft-ietf-decade-integration-example-03

From: Richard Alimi <[email-masked]>
Date: Sat, 12 May 2012 11:10:28 -0700

The following is my review of
draft-ietf-decade-integration-example-03.  Overall, the document is
much improved.  It could still use some general revision for grammar
and to make the wording more concise.

Detailed review:

** Introduction

s/firstly/first

"we only show the feasibility of ALTO and INS without comparing to
other content distribution systems at this time"
  - what other "content distribution systems" would be compared against?
  - if not at this time, is that planned for a future iteration of
this draft (if not I'd suggest removing "at this time")

** Terminlogy

add definition for "native application client"

INS Service Provider
  - does it deploy the entire INS system, or just some servers?

INS Portal
  - why simulated? what's a simulated portal?
  - don't use 'portal' in order to define the term

** INS Client API

define what a 'token' is (or provide a reference)

s/authorized token/authorization token/

why does the particular example (ALTO + INS) determine who generates
the token?  Is this detail necessary in the API description?

** Integration of P2P Live Streaming and INS System

Introductory sentence can be simplified to just "We integrate an INS
client into a P2P live streaming client." The rest is repetative.

what does it mean to be "compatible with original P2P live streaming
signalling"?  Is it more accurate to just say that existing
signallling is still used?

"whose size can be application-customized according to the variable
requirements of of performance or sensitive factors" - wording seems
awkward. How about something like "the API supports variable-sized
blocks to cater to different application requirements (e.g., latency
and throughput)."

For live streaming, in what sense are they "bittorrent-like"?  Piece
exchanges?  (the concept of the torrent file and piece map doesn't
directly apply without modifications)

"On the other hand, INS-enabled .." - remove "on the other hand"

is the token exchange message the reason for the INS Client <-> INS
Client line in Figure 1?  If so, explain in the "Control Messages"
section tha tthis does not use (or extend) the native application
protocol.

To what extent are the recommendations based on the fact that M=1 in
the implementation?  The stronger argument to make might be that the
INS server may need to concurrently serve many thousands (or more)
clients.

"can use this range token to access all available data objects in the
INS server"  - make it clear that it isn't all objects in the server,
but only those to which it was permitted access

The design considerations would be a lot more convincing and easier to
follow if the message flow were discussed before making the
recommendations.  Otherwise, the reader is less clear on the
particular problem being solved.  (Presenting filesharing before live
streaming may solve the problem.)

** Integration of P2P file sharing and INS system

Is Figure 1 basically the same as Figure 2 with the exception of
Figure 2 saying Vuze?  If they are the same, perhaps just present the
general architecture at the beginning of the document and say it works
with both filesharing and live streaming (reuse is a good thing).

Either explain why it is an "Azureous handshake" or replace it with
just "handshake reply" or similar

There seems to be a transition sentence missing before the details of
Figure 4 are discussed.

Are ther eany additional lessons/recommendatons based on the
filesharing integration?  Even if there aren't, it seems like there
should be some sort of concluding remarks in that section.

** Integration of ALTO and INS System for File Distribution

Alto doesn't (typically) give information to end users. It gives
information to applications run by those end users :)

s/content servers/content providers/

alto won't help reduce bandwidth consumption for the end host (the
current text seems to imply that). make it clear that it can reduce
network usage within ISP

s/Architecture Design/Architecture/

how does alto help CPs to upload files ot INS servers?

In Figure 5, why don't End Users talk to INS Servers?  It makes it
look like the CP Portal and INS Portal are on the data path for
downloads.  Similar comment for End Users and ALTO Server.

In Figure 6, why not have the Portal redirect the uploder to an INS
server instead of acting as a proxy? Acting as a proxy means the
portal (a server or set of servers presumably) must have an aggregate
network capacity equal to the sum of the total upload rate that it
wishes to provide to all the INS servers.  By not using the proxy
design, it also means the INS Portal no longer needs to define
protocol messaging for communicating things like placement policies.

s/HTTP_POST/HTTP POST/

In the downloading procedure, is the user using a standard web
browser?  From the description, it seems like there must be some sort
of INS extension installed in the web browser (in order to understand
tokens, know how to communicate with INS servers, etc).  That should
be stated.

What is the relationship between the ISP and the INS Service Provider?
 Does the INS Service Provider have servers in multiple ISPs (in which
case it would make sense to consult ALTO servers from each ISP).  Or
is the INS Service Provider the same as the ISP?

How is "optimal" decided?

** Test Environment and Settings

Avoid using the word "cloud". They are large sets of servers available for use.

wild-spread area -> global?

how is geolocation distance computed?

Figure 9 - also include where the servers were in the figure?  (like Figure 8)

s/leeches/leechers/

would it be simpler to just assume PlanetLab Manager was part of the
text controller and not mention it explicitly?

"4G CPU" -> 4 CPU? (or, did you find 4-Ghz CPUs?)  If you found a VM
with 4 billion CPUs that were halfway-decent, we should chat :)

For filesharing, why is there 480MB of download traffic in the INS
case but 430MB in the native case?

Can an INS server always supply 94%, or only when there was a 1Gbps
NIC?  More specifically, does it supply 9.4Gbps with a 10Gbps NIC?

it would be interesting to note what scaling issues you found passed
400 concurrent users at an INS server.