Capwap Mailing List: Re: Issue 168: DTLS and Retransmissions

[Charles Clancy (clancy]

Suggested text changes to address the comments:

Replace this 2.4.1 text:

   DTLS, as specified, provides its own retransmit timers with an
   exponential back-off.  However, DTLS will never terminate the
   handshake due to non-responsiveness; instead, DTLS will continue to
   increase its back-off timer period.  Hence, timing out incomplete
   DTLS handshakes is entirely the responsibility of the CAPWAP module.

with this text:

   DTLS, as specified, provides its own retransmit timers with an
   exponential back-off.  [RFC4347] does not specify how long
   retransmissions should continue.  Consequently, timing out incomplete
   DTLS handshakes is entirely the responsibility of the CAPWAP module.

I'm not sure what needs to be addressed in 2.4.3.  Pasi -- can you be 
more specific?

--
Dr. Charles Clancy                     www.ltsnet.net/~clancy
Senior Researcher, Laboratory for Telecommunications Sciences


Pat Calhoun (pacalhou) wrote:
> Pasi's comment was:
>
>    Section 2.4.1: "DTLS will never terminate the handshake due to
>    non-responsiveness; instead, DTLS will continue to 
>    increase its back-off timer period" While RFC 4347 doesn't specify
> how
>    long you should continue retransmitting, the 
>    intent certainly was not to continue indefinitely.
>  
>    Section 2.4.3 text about DTLS retransmissions is slightly inaccurate;
>    DTLS handshake isn't strictly request/response, 
>    and both parties (not just the DTLS client) retransmit based on
> timers
>    (in some situations).
>
> It is unclear to me as to whether these are simply observations, or
> request for change. That said, I would like either Charles or Scott to
> reply.
>
> PatC