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Do You Send Occasional Files Via Skype?


NoelC

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This doesn't belong in any particular OS section, as multiple operating systems are involved, but this is the sub-forum I'm most active in, so I'll post it here...

 

Occasionally I collaborate with astronomers in other parts of the world and we've used Skype for a long time to send datasets on the order of tens to a few hundred megabytes.

 

Up to recently such transfers would take a reasonable, expected amount of time, given the speeds of our internet connections.

 

Lately our file transfers involve 5x more data crossing the link as they once did - and thus take much longer.

 

Put simply, sending a 30 megabyte file via Skype from a Win 7 system in England to a Win 8.1 system in the USA now causes more than 150 megabytes of actual data transfer on the network.  This means a transfer that should take less than 5 minutes takes almost 25.

 

No call or other data transfer is in progress; our systems are not carrying other folks' Skype calls or data. The connection is direct.

 

See this screen grab that shows the actual data transferred.

 

http://community.skype.com/skypec/attachments/skypec/Windows/297572/1/SkypeFileXfer.png

 

My question is: Why?  No reasonable protocol has this kind of overhead.

 

Here's the kicker - I've tested file transfers with others and found no such extra data.

 

Do you know of anything we can set to fix this?  What can we do to gather more detailed info?  Could it be a bum Skype installation at the other end (it's up to date)?  Malware?  An alien signal embedded in our own satellite communications?

 

Thanks in advance for any wisdom you can share.

 

-Noel

 

 

P.S., yes, I know of many other alternative solutions - e.g., copying a file to OneDrive, then copying from at the other end, etc.  We've tried them, and they work.  But since we use Skype chat and voice to communicate it turns out most convenient to do it via Skype.  One just sends from the file on one's PC, in-line with the conversation that defines the meaning of the file, then the person at the other end starts the transfer when it's convenient.

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Could it be a bum Skype installation at the other end (it's up to date)?  Malware?  An alien signal embedded in our own satellite communications?

Don't forget to include among the possibilities:

  • A bum Skype installation at your end. ;):whistle:
  • The intervention of any of the three or-more-letters US or UK Government agencies. :w00t::ph34r:
  • A man-in-the middle kind of attack/sniffing/whatever by hacking groups steganographing LOLCAT images in your astronomical photos in order to avoid custom fees. :unsure:.

Seriously, it seems like a very "strange" and "preoccupying" (given the amount of files exchanged globally through SkyPe) issue. :(

 

Which format are the images?

 

I mean it is not that the service is attempting to decompress (for virus scanning or *whatever* reasons)  the contents (or a local antivirus or something similar)?

 

Is this behaviour "bidirectional" (i.e. it happens BOTH if you send or receive the image) AND it happens ONLY with this other user?

 

jaclaz

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Thanks.  As I mentioned, the ability to send the files in-line with the chat is what makes Skype the attractive choice.  We already have alternatives that work (and I do see the advantages of the direct sending process of Sync), but the alternatives just turn out to be intrusive (got to get the file name exactly right, got to share the link, got to remember to delete the file later, etc.).  Skype is already in use.

 

I wonder whether Microsoft is, as with much of its other work, actively trying to destroy the Skype data transfer process so that people will more and more migrate to their stupid "cloud" services.  If this is the case there's little hope for using it in an ongoing way and having it ever be efficient again.

 

Even though it's inconvenient, we may try Sync.  Thanks again.

 

Still looking for anyone with specific wisdom on Skype mechanics...

 

-Noel

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Don't forget to include among the possibilities:

  • A bum Skype installation at your end. ;):whistle:

 

That would be a consideration, save for the fact that I've spot tested with others and have no such failure.

 

 

  • The intervention of any of the three or-more-letters US or UK Government agencies. :w00t::ph34r:

 

The thought crossed my mind, but wouldn't they have to be idiots to alter the transfer process so obviously?  I mean, if the data's all there, couldn't they just lap it up without altering it at all, no?  And as far as I'm concerned, they're welcome to it.  We don't do illegal things, nor would I trust ANY communications process (including that BitTorrent Sync thing above) to not be tapped in some fashion.

 

 

 

  • A man-in-the middle kind of attack/sniffing/whatever by hacking groups steganographing LOLCAT images in your astronomical photos in order to avoid custom fees. :unsure:.

 

Something along these lines also occurred to me, and I really do need to capture some of the data packets and look inside them.

 

 

Which format are the images?

 

I mean it is not that the service is attempting to decompress (for virus scanning or *whatever* reasons)  the contents (or a local antivirus or something similar)?

 

Is this behaviour "bidirectional" (i.e. it happens BOTH if you send or receive the image) AND it happens ONLY with this other user?

 

The images have been things like Canon .CR2 raw files (as shown in the screen grab example), TIFFs, JPEGs, etc.  We've noticed it with images, since those tend to be large.  It happens with both compressible and substantially uncompressible data (I even thought maybe it might be a compression algorithm gone awry).  I tested with the very same .CR2 file with someone else (both of us here in the US) and the data bloat did not occur.

 

My observation of this so far has been with one particular user, someone I collaborate with a lot.  He's only partially computer savvy, and it's entirely possible his system may be infected with something, or that his (ironically AOL-provided) communication line is faulty or tapped.  He has reported some mysterious issues he's attributed to his router lately. 

 

Oh, and I almost forgot:  Yes, the problem is bidirectional with this one user.  I have begun to most suspect a faulty communication line on his end, causing massive retransmissions.  Now, to be fair, we don't get any obvious problems with our voice communications, but I don't know the level of redundancy or error correction in that.  If he IS corrupting large numbers of packets, that could possibly explain what we're seeing.

 

All these things need to be checked further.  Thanks for the conversation; it helps clarify things.

 

-Noel

Edited by NoelC
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Well, of course they *need* (like I do) to add all those u's that you insist on removing from common words, but it is actually a very little overhead, while replacing -ize with -ise does not of course later the length of messages, and when your English friends sends messages to you, the message would be actually shortened on-the-fly.
 
Those are "revocation letter" items #1 and #2 in it's most widely reknown version:

1. You should look up "revocation" in the Oxford English Dictionary. Then look up "aluminium". Check the pronunciation guide. You will be amazed at just how wrongly you have been pronouncing it. The letter 'U' will be reinstated in words such as 'favour' and 'neighbour', skipping the letter 'U' is nothing more than laziness on your part. Likewise, you will learn to spell 'doughnut' without skipping half the letters. You will end your love affair with the letter 'Z' (pronounced 'zed' not 'zee') and the suffix "ize" will be replaced by the suffix "ise". You will learn that the suffix 'burgh is pronounced 'burra' e.g. Edinburgh. You are welcome to respell Pittsburgh as 'Pittsberg' if you can't cope with correct pronunciation. Generally, you should raise your vocabulary to acceptable levels. Look up "vocabulary". Using the same twenty seven words interspersed with filler noises such as "like" and "you know" is an unacceptable and inefficient form of communication. Look up "interspersed". There will be no more 'bleeps' in the Jerry Springer show. If you're not old enough to cope with bad language then you shouldn't have chat shows. When you learn to develop your vocabulary then you won't have to use bad language as often.

2. There is no such thing as "US English". We will let Microsoft know on your behalf. The Microsoft spell-checker will be adjusted to take account of the reinstated letter 'u' and the elimination of "-ize".

 
http://www.snopes.com/politics/soapbox/revocation.asp
 
jaclaz

Edited by jaclaz
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We did more investigation and testing today and came to the knowledge that there are many, many rapid errors being introduced on my collaborator's last mile link.  The excess of data is actually retransmission.  The amount of bytes sent to get the same amount of data through varies a good bit from transfer to transfer of the same file.

 

The protocol's logic to detect and correct errors is covering up the real problem, which I'm guessing is probably something like an overwhelming 50Hz buzz in the circuit.  The next challenge is to get British Telecom to do something about it.

 

-Noel

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The protocol's logic to detect and correct errors is covering up the real problem, which I'm guessing is probably something like an overwhelming 50Hz buzz in the circuit.  The next challenge is to get British Telecom to do something about it.

You see the good thing of the UK ?

If the issue was on your side of the pond, you would have likely had a much higher frequency 60 Hz buzz instead ;).

 

jaclaz

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