Re: [multipathtcp] Options or Payload?

William Herrin <bill@herrin.us> Tue, 10 November 2009 02:37 UTC

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Date: Mon, 9 Nov 2009 21:38:10 -0500
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From: William Herrin <bill@herrin.us>
To: "Ford, Alan" <alan.ford@roke.co.uk>
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Subject: Re: [multipathtcp] Options or Payload?
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On Mon, Nov 9, 2009 at 7:58 PM, Ford, Alan <alan.ford@roke.co.uk> wrote:
> One of the big issues to be raised during yesterday's MPTCP session was
> the question of whether TCP Options are really the right place to be
> doing this.
> Specifically, instead of doing this with TCP Options, the same
> instructions could be included in the payload.
> What do people think is the best approach?

Hi Alan,

There isn't enough room in the options to transfer an encryption key,
a hostname or other likely methods of authenticating the offered
addresses. There isn't really enough to transfer all of the candidate
addresses either, not once we start talking v4/v6 agnosticism, so we'd
have to send adds and deletes instead of updates.

When I tinkered with a throwaway concept
(http://bill.herrin.us/network/multipathtcp2.html) I pretty quickly
moved to the data section because trying to keep it all in the options
got funky fast.

Regards,
Bill Herrin



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