[linux-dvb] Re: video + net with Nexus

[Steffen Barszus <st_barszus@gmx.de>]

Am Sonntag, 21. Dezember 2003 21:31 schrieb Augusto Cardoso:
> Hi!
>
> I may have miss the point here, however, I have run the skystar2
> cards at 38Mbps IP payload speeds without dropping any packets for
> more than 24 hours. With the FCII/FCIIB the maximum speed that I got
> is about 41Mbps. With FCIII I have tested it at 78Mbps and simulated
> it at 120Mbps. (Note this tests were done at B2C2 with B2C2's
> drivers). When I used to work at B2C2, we focus on data applications.
> That is the main reason the B2C2 Windows driver is a NDIS driver and
> the B2C2 Linux driver is a network driver. Unfortunately, the B2C2
> drivers are proprietary and very cumbersome.

The problem is we are not speaking about the skystar2. With the skystar2 
i have no losses, i get easy full speed with it. The problem is that 
the Fujitsu Siemens Rev 1.3 card doesn't work in multicast speed with 
an acceptable prformance (speak 3-4k vs. 120k) . After all the 
explanation i accept it and i think the skystar2 isn't really expensive 
and a second card isn't really bad in a vdr setup ;). If it could be 
solved however it wouldn't be bad as many people have/will have this 
problem. Maybe a sentence in an FAQ "fullfeatured card wont work with 
ip over dvb because of hardware limitations, use budget ones" would fix 
this bug ? ;)

> We did developed a software package for testing data in Unicast and
> Multicast. We also run the data in the same transponder that we run
> the video/audio. We tested receiving all IP data and video/audio
> without any problems.
>
> I haven't done much data tests with the linuxtv.org drivers, mainly
> because my use is for video/audio MPEG2 data.
>
> Can this be a latency issue in the driver? How are you testing? What
> type of applications/protocol? What's the service provider?
>
> 	Augusto
>
> *********** REPLY SEPARATOR  ***********
>
> On 12/19/2003 at 6:00 PM Ralph Metzler wrote:
> >Steffen Barszus writes:
> > > For me the crashes are gone, but you can sure forget to try
> > > dvb/ip over a nexus. I get data rates of 3-4 kB over the nexus
> > > and 120 over a skystar2. If this could be fixed it would sure be
> > > nice, but from current discussions i read that the card "is not
> > > designed to work" for this task and i have it understood, that
> > > this issue wont be fixed.
> >
> >The 120 kB itself are not the problem. The provider is probably
> >sending more than 10-15 Mbit over one PID. At that point the card
> > will start losing data. Neither the internal hardware filters nor
> > the software filters (only because the whole PID has to be moved
> > over the dual-ported RAM in this case) will work properly.
> >

Hmm in multicast this may be true and wolfgang wershofen states that VPN 
(no proxy) works a lot better with these cards. though i have not the 
money to test that (the german telekom want to have a lot to much money 
for that (99EUR +3months subscription)




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