Posted by Gene E. Bloch on 02/12/07 19:11

On 2/09/2007, Gene posted this:

[...]

> I was not aware that the internet protocol had changed, I thought that
> everything was still in multi-packets, and over different paths. It's
> probably
> silly to keep the old security protocol, given that the net is no longer a
> national
> security thing. Guess packet verification is no longer really all that
> necessary.
> Geesh, I have not seen a parity check in years:-)

[...]
"Rick Merrill" <rick0.merrill@NOSPAM.gmail.com> wrote in message
news:Ws2dnb9h_s5DclHYnZ2dnUVZ_uednZ2d@comcast.com...

[...]

>> Well you got the transmission by packets right - but the truth is that the
>> odds are HUGE that each packet will in fact take the same path.

[...]

Just a few comments here for clarity.

1. The transmission by packets is NOT for security, Gene. It is because
it is hard (impossible?) to transmit a whole lot of bits in a huge
single block without any errors. So you send a lot of small blocks,
each with error checking data. If the received block is incorrect, the
receiving stations asks the sender for a retransmission. This has been
the norm for decades (e.g., xmodem, zmodem).

2. A corollary of that is that, in the multi-connected net of today,
these packets don't all have to take the same path to get to the final
destination. This would happen for sure if one of the intermediate
nodes failed during a long series of blocks. I have no idea how rare it
is for one collection of data to get to you by varied paths, but I
would tend to agree a little with Rick Merrill. I would just say it's
usual for the data to all use the same path, but not at all impossible
for paths to vary.

3. I don't chink the Internet Protocol has changed. I *do* think your
understanding of it is changing :-)

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

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