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Date: Tue, 6 Dec 2011 11:21:53 +0000
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Andreas Oberritter <obi@linuxtv.org>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>, HoP <jpetrous@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>, linux-media@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC] vtunerc: virtual DVB device - is it ok to NACK driver
 because of worrying about possible misusage?
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On Mon, Dec 05, 2011 at 09:41:38PM +0100, Andreas Oberritter wrote:
> On 05.12.2011 18:39, Mauro Carvalho Chehab wrote:

> > When you put someone via the network, issues like latency,  package
> > drops, IP
> > congestion, QoS issues, cryptography, tunneling, etc should be taken
> > into account
> > by the application, in order to properly address the network issues.

> Are you serious? Lower networking layers should be transparent to the
> upper layers. You don't implement VPN or say TCP in all of your
> applications, do you? These are just some more made-up arguments which
> don't have anything to do with the use cases I explained earlier.

For real time applications it does make a big difference - decisions
taken at the application level can greatly impact end application
performance.  For example with VoIP on a LAN you can get great audio
quality by using very little compression at the expense of high
bandwidth and you can probably use a very small jitter buffer.  Try
doing that over a longer distance or more congested network which drops
packets and it becomes useful to use a more commpressed encoding for
your data which may have better features for handling packet loss, or to
increase your jitter buffer to cope with the less reliable transmit
times.