Re: Glade :- he distributed Annex

[dennison@telepath.com (Ted Dennison)]

Ole-Hjalmar Kristensen <oleh@vlinux.voxelvision.no> wrote in message news:<7vit76kth4.fsf@vlinux.voxelvision.no>...
> dennison@telepath.com (Ted Dennison) writes:
> > Considering that TCP itself can't be used for that kind of real-time
> > application (and IP itself can't either, except under certian
> > circumstances), that's a pretty safe statement.

> On the other hand UDP/IP is perfectly good enough to run fault tolerant 
> *soft* real time systems in a workstation cluster. In other words, good enough 
> for a telephone company, but don't try running your engine controller on it.

Mostly. As I alluded to, it *can* be used for hard real-time, under
some very specific circumstances (dedicated direct link, with no other
applications using it, no outside traffic forwarded onto it, and a RT
IP stack). The main non-determinisim in IP comes in with the
collision/retry mechanisim, and with routing issues. We did this with
the last simulator I worked on. It allowed us to use a well-known API,
and industry standard PC's. It would have made the whole thing damn
cheap, if it weren't for the >$200K of custom hardware we had to
drive. :-)


-- 
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