[JDEV] File transfers

[Mike Oliver]

Why have just one protocol?

SMTP does pretty well at file transfers that are asynch.  The Jabber 
protocol can include a header for the attachments and the user at the other 
end can decide if they want to download the file.  The a request can then 
be sent to the originating peer and an SMTP transfer begun and the remote 
client can notify the user when the transaction is complete by asking where 
to put the file.  There are SMTP libraries in almost every language you can 
name, so this doesn't appear to be a big problem.

FTP is another and offers the ability to transfer files without the base64 
encoding.

Ollie

At 11:45 AM 6/5/2002 -0400, you wrote:

>In-band transport of large payloads is something we and others have been
>looking at pretty intensely. Obviously it would be a nice thing to have,
>but it is also very, very difficult to do properly. If you just stick
>base64 in an X element, you have huge problems because if that takes 10
>minutes to transmit, you can't send anything else for those 10 minutes. You
>could chunk them, but that hardly makes things simpler for the client
>software. This also makes it massively more difficult to distinguish
>legitimate traffic from a denial of service attack. Furthermore, it means
>the server has to do a whole lot more XML processing (which may already be
>a bottleneck), because all XML content has to be at least checked for
>well-formedness. To speak nothing of the bandwidth implications.
>
>Ultimately, I don't believe there is a satisfactory way to transport large
>payloads in-band while keeping things simple for the client. The solution
>to this problem will involve a more complex system on the client endpoints
>- though not necessarily in typical client software.
>
>-Mike
>
>
>
>|---------+---------------------------->
>|         |           Andy Beetz       |
>|         |           <andy.beetz at clear|
>|         |           swift.com>       |
>|         |           Sent by:         |
>|         |           jdev-admin at jabber|
>|         |           .org             |
>|         |                            |
>|         |                            |
>|         |           06/05/2002 10:29 |
>|         |           AM               |
>|         |           Please respond to|
>|         |           jdev             |
>|         |                            |
>|---------+---------------------------->
> 
>  >------------------------------------------------------------------------------------------------------------------------------|
>   | 
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>   |       To:       "'jdev at jabber.org'" 
> <jdev at jabber.org> 
> |
>   |       cc: 
>                                                         |
>   |       Subject:  [JDEV] File 
> transfers 
> |
>   | 
>                                                         |
>   | 
>                                                         |
> 
>  >------------------------------------------------------------------------------------------------------------------------------|
>
>
>
>I've set up jabberd and got a couple of clients connecting to it (winjab).
>I
>tried a file transfer which worked no problem. What I saw looking at the
>Winjab source is that the receiver downloads the file from the sender on
>it's own socket based connection.
>
>I'm just thinking that there should be a better way to do this and inside
>the message. I'm not saying my idea is the best or anything, but I do think
>that it would present the client authors with less headaches. Anyway, my
>idea is that a message element can have a child, let's say attachment or
>even an x, which will contain the contents of the file. XML can handle this
>if the file is base64 encoded, as it ends up as plain text.
>
>Just some thoughts
>Andy Beetz
>
>
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Michael Oliver
Chief Technology Officer
AppsAsPeers.com
7391 S. Bullrider Ave.
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