Re: Originally Re: [MSG-1] SR1 Traffic dial. - now missed packets


geojohnt@...
 

David,

Thanks again for your further information.

Regarding the 'stuck' TC red icon issue, 'now I know.'
It seems the red icon may have misled me into thinking that I had 42 minutes of no HVS-1 reception.
Demonstrated another day by seeing data flowing on the HTML Shell graph whilst a red icon was showing.

Might be worth taking this up with EUMETSAT?

Regarding PC activity and missed packets, despite my PC being able to cope with its high processing demand from all your programmes running at the same time, I think I added to missed packets yesterday having been using HRPT Reader and GSS to process and display Metop and and MSG Hi-Res images - 'at the same time.'

Anyway, as I said earlier, I'm not aware of and image gaps so there is no problem.

>As I've mentioned many times before, automatic monitoring with e.g. MRTG can
>help you tie periods of loss to periods of high CPU, low memory, high
>network I/O, or scheduled malware scanning.  Otherwise it's more guesswork.

Indeed you have.

It would be an interesting exercise but since I'm not suffering image degradation, it's just another thing to set up.
And really, I guess, I don't need the EUMETCast computer connected to wifi 24/7 in which case I could turn off 'active' BullGuard scanning?
I only need Internet access on that computer to upgrade SatSignal programmes.
Oh, and importantly kepler updates.

Regards,
John.



In a message dated 29/09/2019 16:22:37 GMT Standard Time, gm8arv@... writes:


The red icon behaves differently in two circumstances:

- with signal loss and restoration the icon goes red and then clears.

- with some file errors the icon stays red, until you reset it.  The error
message gives a clue to the problem.

I think the present behaviour is satisfactory, once you know the above.

The missed/recovered packet count can be greater if the link margin is
lower, yes, particularly if there are variations in the signal causing
momentary drop-outs (wind is a cause in this location).  The lower the link
margin, the greater the chance of it being below the threshold.

Even with the perfect signal (well, 4 dB or greater steady link margin), if
any PC activity causes the data stream to be interrupted, that can result in
lost packets.  Yes, virus scanners can cause this, so if the PC doesn't have
any users, turn off the scanner, of if there's a keyboard someone can
interact with stop the scanner looking at the EUMETCast directories.  In the
past, a RAMdisk has been shown to ameliorate this problem, but I'm not so
sure these days with faster PCs and updates to TelliCast.

As I've mentioned many times before, automatic monitoring with e.g. MRTG can
help you tie periods of loss to periods of high CPU, low memory, high
network I/O, or scheduled malware scanning.  Otherwise it's more guesswork.

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