Re: Gibson Magic - A/D conversion - and fun with hacking Magic

--- In midiguitar@xxxxxxxxxxxxxxx, Tom May <tom@xxxx> wrote:
> WRT the discussion below:
> 
> Are you sure Gibson chose UDP simply because it has a litle less
> overhead than TCP?  My guess would be that they chose it because it 
is
> stateless, and simple at both the application layer and the IP 
layer.
> You just send data and forget about it.  No timeouts.  No retries.  
No
> blocking writes.  No broken connections that need to be 
reestablished.
> No complicated TCP stack.  If they really can't squeeze 24/96 data
> down a wireless link with TCP (and they can't squeeze it down an
> 11Mbps link, which never run that fast anyway, so already you're
> looking at one of the faster systems), then the 20 bytes/packet
> savings that UDP gives is not going to help much.  Compare that to a
> single six-channel 24-bit sample occupying 18 bytes.  You don't want
> to run that close to the edge.
> 
> But bandwidth, security, and encrpytion issues aside, a wireless
> signal of any kind can be interfered with.  My wireless network can 
be
> jammed by a cordless phone.  Not exactly hijacking, but bad enough.
> 

Absolutely.  Both reasons.  Even if overhead was no issue, the 
tendency of TCP to resend packets of something happens in transit 
could potentially lead to all sorts of havok if things go wrong.  You 
hear double notes, things start getting delayed, etc.  With UDP you 
just experience a quick (and maybe unnoticable) dropout.

The thing about the 20 bytes is that with all of this data, you end 
up sending a LOT of packets, and the overhead can start to add up.

Also, if things go wrong, with TCP the receiving end has to clean up 
the connections which can take a while.  SImilarly when you UDP flood 
a port when the UDP flood stops, the port is immeditately free (CPU 
and memory issues not withstanding).  With TCP, the receiver has to 
shut down all of those errant open connections.  The result is that 
the receiving port can stay "blocked" for a period of time (from ms 
to many seconds).

So, UDP was chosen for BOTH of these reasons, and I think it was a 
smart choice.  I just think their wireless vision (until technology 
improves, and it probably will by the time this technology starts to 
permeate the market place - if it does) needs some rethinking!

BTW, I was mistaken in that you can actually put **5** repeaters on 
ethernet, not the 2 that I mentioned.  All the more reason NOT to go 
wireless.

Still, if it's available, you know some people will go wireless 
anyway...  :-)

Alex F/Brain21


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