[Embedlets-dev] Peer-to-peer or master/slave

[Bruce B. <bb...@sy...>]

At 01:01 PM 6/27/2003 -0700, 
emb...@li... wrote:

>It is just an idea, but it will work just fine.  It will provide a network
>exactly like you would see with a TCP/IP switched network, in terms of
>topology.  Broadcast networks are fine for one or two users, but degrade
>quickly...  There's plenty of experience that says about 20% utilization is
>all that you can count on before you get a dramatic degradation for each
>percentage above that.
>
>Clearly there is research going on that has shown some ways to make the
>degradation less dramatic (search google for 'CSMA degradation').  LonWorks
>has a proprietary solution as do others specific to their use.  The easies 
>and
>simplest is the round-robin, equal time, equal access mechanism that I
>described.  It will provide dependable, predictable data transfer from one
>peer to another.

...only if there is a reliable master, if I understand your idea. In a true 
peer-to-peer ad-hoc (I realize I added that just now) network you can't 
count on any node being present at any time. In fact, in any realtime 
control network I think that is a good assumption. Whatever nodes happen to 
be present carry on as best they can, rather than the whole network just 
crashing.

So if a master is required to facilitate all communication amongst slaves 
there can be no true peers. Only the master and slave(s), and the network 
should not be called a peer network.

Bruce