[newbie] trying socket as a replacement for nc

[88888 Dihedral]

>  88888 Dihedral <dihedral88888 at gmail.com> wrote:
> 
> 
> 
> > It is trivial to use UDP with 
> 
> > forward error correction such as 
> 
> > the CD in 1982.
> 
> 
> 
> CD uses Reed-Solomon coding, which is great for correcting the types of 
> 
> errors expected on a CD.  Namely, bursts of bit errors caused by 
> 
> localized failure of the optical coating, scratches, dirt, etc.  It 
> 

Don't you interleave your bytes of data
first before forming several UDP 
packets to send to the receiver?

If a whole packet is lost or 
timed out, then just mark missed bytes
in the missed UDP as erasures.

> wouldn't be hard to build something like that on top of UDP, but those 
> 
> sorts of errors are not what you typically see in networks.
> 
> 
> 
> It's relatively rare for a bit to get corrupted in a network packet.  
> 
> And, when it does, it's almost certainly caught by lower-level 
> 
> mechanisms such as ethernet frame CRC.  Much more likely is for a packet 
> 
> to get dropped because of queue overflow, or for sequential packets to 
> 
> arrive out of order due to multiple transmission paths with different 
> 
> latencies.  Those are the sorts of things TCP protects against.
> 
> 
> 
> Sure, you could implement retransmit timers and packet reordering in 
> 
> user code, but it would be distinctly non-trivial and ultimately you 
> 
> would end up reinventing most of TCP.  Except that your implementation 
> 
> would suck compared to the kernel algorithms which have been 
> 
> continuously tested and fine-tuned for the past 30 years.