Re: [Embedlets-dev] Global Light Blinker Project (approach JINI community too)

[Ted K. <tk...@ya...>]

Gregg wrote:

> In the end, IP routability does not disappear.  Thus, there have to be well 
> known addresses for rendezvous.  This means that while the peer groups might
> be dynamic, you must have a server infrastructure with well known addresses 
> somewhere [...] there is still no possibility of two NAT'd JXTA peers finding
> each other without some well known address to find a rendezvous.

One only needs a well known initial rendezvous address to bootstrap a
PeerGroup.  After a PeerGroup is bootstraped the PeerGroup's rendezvous can
dynamically scale up and down in number and move around.  If all of the
rendezvous in a PeerGroup would somehow drop offline, the Peers themselves are
designed to fire up their own Rendezvous services in order to keep the
PeerGroup online.  Beyond this, Rendezvous can even be situated behind
firewalls and NATs.

The main server infrastructure that is absolutely needed on the open internet
are JXTA Relays so that devices behind firewalls and NATs can participate in a
PeerGroup.

Anyway, I think that remotely controlling devices is unlike illegal file
sharing where one is in danger of having one's servers shut down.  The cost for
server hosting of Rendezvous and Relays is very reasonable and so I do not view
this issue as being a major problem.



> While 128 bits is a big number, it is still possible for duplicates, so the 
> UUID must be generated with many important considerations such as MAC
> address, date/time etc.  So, you must follow the rules, and thus consider
some > aspect of your physical environment if you are going to operate in the
world 
> community.

Agreed.  And the JXTA reference implementation already comes with the proper
tools for creating world-community class UUIDs and so I am not too concerned
about this issue either.  If this issue eventually does become a problem I
think that the JXTA developers can be relied upon to come up with a solution.



> This is where you have to be careful.  JXTA provides protocols between JXTA 
> clients that allow a proxy (of sorts) to interconnect them.  This is a well 
> known architecture.  I have a proxy at my work location that an X-10 server
> at my house (whose network is NAT'd) connects to.  My J2ME phone connects 
>to the proxy which then provides the connecting pipe between the two 'worlds'.

Is the connection between your phone and your in-home proxy secure at the
transport level (including over multi-hop networks) and also as the
authentication level?  Can anyone who has the appropriate credentials securely
log into your in-home domain from anywhere on the internet using any class of
device?  JXTA 2.0 includes the technologies which are needed to do these things
which is one of the main reasons that I am excited about it.



> There are many competing technologies working in the world of distributed 
> computing.  JXTA is very interesting.  I'm on the Jini wagon because it 
> provides the solutions that I need for the same types of problems. [...], and
> in the end, the first technology to deploy the next killer application, 
> may end up with the momentum to carry the lead...

As people like Bruce Boyes can tell you, at JavaOne this year I expended a ton
of energy trying to determine whether to go with JINI or JXTA.  After sitting
in on most of the JINI and JXTA sessions, and asking developers in both
communities where these technologies excelled and where they overlapped, I
still did not have a good answer by the last day of the show.  I did discover,
however, that the JINI and JXTA communities do not talk very much and this
surprised me.

Thankfully, the last session of the last day of the show was about using JINI
and JXTA together and during this session it all fell into place for me.  The
presenter showed how JINI was operating at a higher level of abstraction than
JXTA was and that a very reasonable thing to do was to use JINI on top of JXTA
and to not worry too much about the levels where they overlap.

I very much admire both of these amazing technologies and after attending this
session I felt relieved about there being a good chance that they will
cooperate in the future.


So Gregg, what about bringing the JINI community into this Global Light Blinker
project too?  As an Embedded Java developer, I am extremely excited about the
prospect of any group making use of Embedded Java technologies and if we are
about to go through the effort of coming up with a Secure Outpost standard, why
not make it so that JINI based software can use these devices too?

Bringing the Embedded Java and 'Computer Science' Java worlds closer together
is one of the Embedlet Projects stated goals and so including the JINI
community in this project seems like a great way support this goal.


Ted

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