Re: [clue] Benjamin Kaduk's Discuss on draft-ietf-clue-protocol-17: (with DISCUSS and COMMENT)

[Adam Roach <[e-mail]>]

Trying to help out a bit on one of the discuss points...

On 11/19/18 12:25 PM, Benjamin Kaduk wrote:
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> DISCUSS:
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>
> Thanks for the generally clear and well-written document!
> I would like to discuss whether there needs to be more prominent coverage
> of timers/timeouts, especially as relating to the state machines.  (I'd be happy
> to learn that this is well-covered elsewhere in the document set; I just haven't
> run into it yet.)


The initial document included several timers that triggered 
retransmissions of messages -- but since the CLUE protocol uses TCP as a 
substrate, these kind of application-level retransmissions can cause a 
spike of traffic when the networks starts getting congested, which is 
the opposite of what we want to happen. So they were removed, and the 
protocol now relies exclusively on the reliability mechanisms provided 
by TCP both for retransmission and for detection of connection failures.

In terms of supervising the overall lifetime of the state machines, it's 
important to keep in mind that these operations always take place within 
the context of a larger session (e.g., a SIP session), which naturally 
limits how long the state machines can live: at the end of the 
corresponding session, all CLUE state goes away.

/a