Re: [TLS] TLS Record Size Limitation

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 08 December 2015 10:12 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Dave Garrett <davemgarrett@gmail.com>, Software Engineer 979 <softeng979@gmail.com>
Thread-Topic: [TLS] TLS Record Size Limitation
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Date: Tue, 8 Dec 2015 10:11:52 +0000
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Subject: Re: [TLS] TLS Record Size Limitation
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Dave Garrett <davemgarrett@gmail.com> writes:

>A TLS extension to negotiate max length might be viable.

I think a better starting point would be to look at the implementation that's
causing the problem.  There's nothing magical about a 16K max segment size
that causes poor performance, TCP typically has an MSS of 1400-1500 bytes, one
tenth of the TLS segment size, without there being a 187% loss in throughput
so it looks like the problem is in the implementation, not the protocol.  I
don't see any reason why you couldn't get close to wire speeds, or at least
min( crypto speed, wire speed ) for TLS for a properly-done implementation.

Peter.