Subject: Re: [linux-audio-dev] Gibson magic protocol
From: Martijn Sipkema (msipkema_AT_sipkema-digital.com)
Date: Wed Apr 16 2003 - 02:50:24 EEST
> On Tuesday 15 April 2003 19.40, Martijn Sipkema wrote:
> [...]
> > It will _not_ coexist with standard Ethernet
>
> Right; it *can't*, unless all machines on the network have a hard real
> time layer between the NICs and the protocol stacks. There are
> protocols that would work for running RT streaming together with
> normal network traffic, but there's no way around the fact that all
> nodes must be hard real time. (Well, except for building it into the
> hardware, perhaps...)
>
>
> > and I doubt a NIC can
> > be used because the timing is very critical.
>
> That's not a problem normally, as most NICs have hardware latencies in
> the microsecond range. All you need to implement hard QoS guarantees
> is an RTOS, RT safe drivers and a suitable protocol.
Actually, from the specs:
"The default MaGIC frame timing is 48 kHz with an acceptable tolerance
of 80 picoseconds."
I think this needs to be implemented in hardware.
--ms
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