Re: A couple of introductory questions

[Timothy Stack <stack@cs.utah.edu>]

> Hello from a newbie:
> 
>   My name is Peter Lutz and I am a Professor of Information
> Technology at Rochester Institute of Technology in Rochester,
> NY.  I have a couple of questions about JANOS that perhaps
> you can answer for me.  At the end of this email, FYI, is
> a short intro to why I care and who I am, as I may have
> other questions in the future, and you might be able to help
> me in that case.
> 
> QUESTIONS:
> 1. The most important regards the layered architecture
> of the JANOS system.  On the page:
> 	http://www.cs.utah.edu/flux/janos/index.html
> a layered architecture is displayed.  Is this still accurate?
> In particular, for a stand alone system, does one still
> need (from the bottom up) the OSKit, Moab, then the JanosVM
> and the Java NodeOS and then ANTS?  

Yes, they all provide different pieces of the puzzle.

  OSKit - The device drivers and network/cpu resource controls
  Moab - Provides a NodeOS standard API on top of the OSKit
  JanosVM - Runs the java code and manages the memory resources.
  Java NodeOS - Provides the java version of the NodeOS API
  ANTSR - An actual active networks EE that uses the java NodeOS API.

> 2. If the answer to the above is YES, then in the case of
> ANTS running on top of UNIX, where is the NodeOS?

The java nodeos can be configured to work with JanosVM/Moab or a regular
java VM.  However, there are no resource controls when running on a
regular JVM, but it works well enough for testing/experimenting purposes.

> Is it the eumlation .jar file???

The emuJanosVM.jar file provides some JanosVM specific classes that the
java nodeos uses.  If the java nodeos was running on top of JanosVM than
it would use the real classes which provide separation/class sharing and
other JanosVM specific things, otherwise we just use the fake ones.

> This is what I suspect, but
> I am uncertain.  Also, is there a layered diagram for this
> emulated environment that I could view?

Not really, just replace JanosVM and below with a regular JVM and regular
OS.

> Thanks in advance for your time.

> Pete Lutz

thanks for your interest and good luck,

tim stack