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The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:11:01
Ben Laurie (ben@algroup.co.uk)
Thu, 27 Aug 1998 16:20:41 +0100
proff@iq.org wrote:
>
> > Here's what I've located on reliable multicast. I'm interested in reliable
> > distribution of 200+ GB files via a DS3 satellite link to 5,000+ recipients.
> > In most cases I'll have a real-time terrestrial reverse link but for some
> > cases the link only comes up after the initial transmission is complete.
> >
> > It's turning out to be an interesting problem.
> >
> > /pbp
> > ====
>
> This isn't a hard problem to solve, but before you can design an
> optimal solution many more variables need to be clarified. i.e how
> fast must errors be resolved, what is the likely packet loss, what
> is the typical rtt/bandwidth on the return link, how fast can new
> data be injected into the sat stream, what are the cost minimisation
> variables, what is the shape of the error curve, what are the
> limitations on the use of ECC and processor cycles, etc.
And, of course, these variables are always known in advance :-)
The reason the problem _is_ hard, is that most of these quantities are
either vague, or have rather wide ranges. In real life, you probably end
up with two or three schemes that each apply to a broad range of
requirements (certainly that is what current research seems to be
converging on), and do their best to adapt dynamically to what is going
on.
Cheers,
Ben.
-- Ben Laurie |Phone: +44 (181) 735 0686| Apache Group member Freelance Consultant |Fax: +44 (181) 735 0689|http://www.apache.org/ and Technical Director|Email: ben@algroup.co.uk | A.L. Digital Ltd, |Apache-SSL author http://www.apache-ssl.org/ London, England. |"Apache: TDG" http://www.ora.com/catalog/apache/WE'RE RECRUITING! http://www.aldigital.co.uk/recruit/
The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:11:01