OT Newsgroup File Size

[george41407]

This is sort of off topic, but I was not sure where else to ask.

I dont understand this. When I download a binary file on a newsgroup,
my newsreader (for example, a MP3) shows the file size as
approximately One Meg. But when I download it, it ends up being
around 80 megs. Why does the newsreader show it as 1M when it's much
much larger?

Another thing. When I am downloading a binary or even text messages,
my internet connection button shows bytes sent and bytes received.
For example, right now it shows about 30megs received and 1.4megs
sent. Why does it SEND bytes? What is is sending? I've used the
internet for years and never understood this.

Thanks
George

 

[Marcel Overweel]

This is sort of off topic, but I was not sure where else to ask.

I dont understand this. When I download a binary file on a newsgroup,
my newsreader (for example, a MP3) shows the file size as
approximately One Meg. But when I download it, it ends up being
around 80 megs. Why does the newsreader show it as 1M when it's much
much larger?

Another thing. When I am downloading a binary or even text messages,
my internet connection button shows bytes sent and bytes received.
For example, right now it shows about 30megs received and 1.4megs
sent. Why does it SEND bytes? What is is sending? I've used the
internet for years and never understood this.

Thanks
George

Mostly, data transfer between any sort of device is done in blocks.
The same is true for internet communication protocols.
Your computer need to send information about what it wants, then
it gets an answer.
After that, data blocks are coming in and your computer needs to
respond to every block saying like "yes I've got it" or "didn't get it,
can you re-send" (ofcourse these things aren't sent as plain text).

This proces is called handshaking.

As for the 1MB / 80MB difference, I am not sure.
Maybe you downloaded a multi-part file where each part is 1MB
in size?
I guess this depends on the newsreader you are using.

regards,
Marcel

 

[george41407]

Mostly, data transfer between any sort of device is done in blocks.
The same is true for internet communication protocols.
Your computer need to send information about what it wants, then
it gets an answer.
After that, data blocks are coming in and your computer needs to
respond to every block saying like "yes I've got it" or "didn't get it,
can you re-send" (ofcourse these things aren't sent as plain text).

This proces is called handshaking.

Thanks, that makes sense. I understand it now....

As for the 1MB / 80MB difference, I am not sure.
Maybe you downloaded a multi-part file where each part is 1MB
in size?
I guess this depends on the newsreader you are using.

regards,
Marcel

Not a multi-part. It was a large song over 10 minutes in size. All
one file. I actually went back and looked at the actual example. The
file was listed in AGENT 2.0 as almost exactly 1meg (on the newsgroup
files list). The actual download was about 60megs. The saved MP3
file ended up being 45megs. I can understand the 60megs becoming 45
megs saved, because of the (I'll call it overhead) of the download.
But listing it as 1meg in the messages just dont seem to make much
sense.

I just saw someone post a 3meg song. On my dialup connection that
would take days to download. That 1megger took around 7 hours.

George

 

[Marcel Overweel]

Thanks, that makes sense. I understand it now....

Not a multi-part. It was a large song over 10 minutes in size. All
one file. I actually went back and looked at the actual example. The
file was listed in AGENT 2.0 as almost exactly 1meg (on the newsgroup
files list). The actual download was about 60megs. The saved MP3
file ended up being 45megs. I can understand the 60megs becoming 45
megs saved, because of the (I'll call it overhead) of the download.

Correct, NNTP (usenet usenet) has a lot of overhead.

But listing it as 1meg in the messages just dont seem to make much
sense.

I just saw someone post a 3meg song. On my dialup connection that
would take days to download. That 1megger took around 7 hours.

George

1MB 7 hours, 3MB about a whole day maybe (3x 7 hours?).
Sounds like the 45(or 60)MB file was compressed to 1MB.
Strange... didn't know nntp had compression.
Don't have a clue about this one

regards,
Marcel

 

[jaster]

Thanks, that makes sense. I understand it now....

Not a multi-part. It was a large song over 10 minutes in size. All one
file. I actually went back and looked at the actual example. The file
was listed in AGENT 2.0 as almost exactly 1meg (on the newsgroup files
list). The actual download was about 60megs. The saved MP3 file ended
up being 45megs. I can understand the 60megs becoming 45 megs saved,
because of the (I'll call it overhead) of the download. But listing it
as 1meg in the messages just dont seem to make much sense.

I just saw someone post a 3meg song. On my dialup connection that would
take days to download. That 1megger took around 7 hours.

George

Well, something is wrong. Mp3 are 1-6mg in size unless it's a complete
album (30-60 minutes) in which case the original post was incorrect.

As I said the original post could have been incorrectly posted. With
dialup if the connection isn't clean the download repeats itself several
times before completing. The transmission has static with the
connection handshaking, causing repeated attempts to synchronize the
connection and download.

 

[george41407]

Well, something is wrong. Mp3 are 1-6mg in size unless it's a complete
album (30-60 minutes) in which case the original post was incorrect.

As I said the original post could have been incorrectly posted. With
dialup if the connection isn't clean the download repeats itself several
times before completing. The transmission has static with the
connection handshaking, causing repeated attempts to synchronize the
connection and download.

The actual length of this song is exactly 17min 10 sec. Remember
Iron Butterfly - 'vida long version. These rural dialups are never
clean, and my max speed is 45K (usually 42K).

George