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Date: Thu, 10 Jan 2013 08:45:01 +1100
Subject: Re: ANN: PyDTLS
From: Chris Angelico <rosuav@gmail.com>
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Xref: csiph.com comp.lang.python:36521

On Thu, Jan 10, 2013 at 7:04 AM, rbit <py@liquibits.com> wrote:
> The following are some of the main use cases that force applications into
> datagram protocols:
>
>     * Minimizing protocol overhead. TCP has relatively high overhead,
>       for example, its 3-way handshake for connection establishment.
>       One can see why DNS uses UDP.

Yep. Related to that: One of our systems at work uses UDP rather than
TCP in order to simplify the detection of node loss. Rather than
working with TCP retry etc and handling the variety of different ways
in which "the other node is down" could be reported, the nodes simply
send UDP packets to each other, and keep track of the timestamp when
one was last received. There's only one failure state: silence. Not
sure if high-level protocol simplicity counts as the same thing or
not; it's a different form of overhead.

ChrisA