Re: Lot of missing segments (Windows 7)


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

Hi,

I am trying to set up my new EUMETCast reception PC under Windows 7 and I am having a lot of missing segments. Statistics of Tellicast 2.4.4a show lot of "missed packets before FEC". With the same antenna I am using a second and very old PC with Win XP working without any looses. Both, have 0 value for BER at Setup4pc GUI.

I have tested with other Skystar2 Card but I get the same result. I have disabled all windows services recomended by Eumetsat. Search indexing seemd to be the trick, but there is something more.

I have tuned the system to best performance, and just receiving Channel 2. Ramdisk for tem file...

I see some of you have the eumetcast pc working under WIN7, did you find something that really makes the difference to have the system working without looses. I'm thinking about going back to WinXP for this new pc also.....

Any comment highly appreciated.

Dan.
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Dan,

The single-core Windows XP receive-only PC (with an old 1.9 GHz Pentium 4) is essentially lossless. It has a SkyStar 2.6D PCI card, and a 100 Mb/s network interface. For 24 x 7 operation, having a two-PC system means that you can take your processing PC down for those all-important Windows Updates without losing any data.

I have three Windows-7 systems which are both receiving and processing, and perhaps I have been unlucky but none are completely lossless even after trying to trim as many services etc. as I could:

- PC Alta which is a recent quad-core PC is almost completely lossless, even though it has a 1 Gb/s network interface. It's using the DVB World USB-connected receiver. Some network-intense operations (1 GB downloads and large transfers between PCs) can produce missed packets which are not recovered. However, this PC is becoming my main interactive PC, so I would expect more losses to come.

- PC Stamsund has a hyper-threaded processor and SkyStar 2.6D PCI card, receiving and processing Meteosat-8 and Meteosat-9 data. I needed to turn down the network speed from 1 Gb/s to 100 Mb/s to achieve near-lossless operation, and even now if I burn a DVD or do some other disk-intensive operations I can lose data.

- PC Hydra is a very old Compaq with a single-core AMD processor, trying to receive the full EUMETCast stream (including all the Metop data) with the exception of Rapid-Scan. It's overloaded, and no longer typical of what might be in use today.

So if you can run XP without loss, I would ask, "Why change?".

Do also note that recently there have been a few missed packets seen across Europe - I'm talking about 2 missed and two recovered yesterday, for example, not very large numbers. But there have also been some weather-related outages at the uplink station a week or two back. So it may be worth checking what others a are reporting if it's just the occasional packet which is missing. There are some graphs here:

http://www.satsignal.eu/mrtg/performance_eumetcast-europe-packets.php

Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@...

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