On Saturday 07 June 2003 12:44, Jeremy C. Reed wrote:
> On 7 Jun 2003, Bryce C wrote:
> > That's exactly the problem. With packet loss and no error checking, that
> > last c may be garbled and thus ignored by rm/bash. There's a reason SSH,
> > telnet, http, etc are all on TCP and not UDP.
False. UDP has CRC checking to verify packet integrity. It just doesn't care
whether a packet got there or not. So, the "last c" will either show up or
you type it again - it will NOT be a garbled character.
>
> Back in the mid to late 1980's, I wrote a bunch of xmodem and BBS software
> (in Turbo Pascal). I used simple checksums to verify the data before
> acknowledging successful receipt (or complaining to resend). It would be
> simple to add that to a UDP-based remote login tool.
Yes, it would be easy to add those features. UDP just leaves error
correction (bad checksum == drop packet), sequencing, flow control, etc. up
to the application itself. UDP is a very simple protocol compared to TCP.
>
> But I don't see any advantage over using TCP and a regular SSH (or
> SSL-telnet or kerberized telnet) even for some "extremely unreliable
> connections such as a high altitude weather balloon communicating over
> packet HAM radio." :)
>
> Jeremy C. Reed
> http://bsd.reedmedia.net/
-dallas
>
>
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