Subject: Re: [Anima-bootstrap] agenda and details for Tuesday

From: Michael Richardson <[email-masked]>
Date: Wed, 01 Mar 2017 11:31:40 -0500

Brian E Carpenter <[email-masked]> wrote:
    >> And this led me to thing that the Registrar discovery probably needs a full
    >> NEG_SYN, rather than M_FLOOD or M_DISCOVER...

    > You could do both. Use Flood as the baseline and Negotiate or
    > Synchronize if the baseline info is insufficient.

Please remind me if I've gotten the flow wrong, I just re-read section 3.8.4
and 3.8.5 and 3.8.6 of grasp-09.

Does it go:
     Proxy             Intermediate        Join Registrar

     M_DISCOVERY --> MCAST
                        M_DISCOVERY--->MCAST
                              <---- unicast----  M_RESPONSE (I'm here)

        <----unicast---- M_RESPONSE (he is there)

     M_REQ_NEG ---------unicast----------------->
               <---------------------------------

that is, the intermediate is just caching the location of the Join Registrar,
and really if we want to do negotiation, we should do it directly?

In this context, I don't see much difference, as you say, between M_DISCOVERY
vs M_FLOOD, except for when it occurs and the need to keep the cache of
things around.  In either case, the locators that we were discussing ought
really to only tell the Join Proxy where to find the Join Registrar's
grasp daemon, not where to find the registration system itself.

    > I'm not sure if GRASP is Turing-equivalent, but I think you
    > can probably do anything you want.

ha. I await the HAL9000 GRASP objective to be defined.

--
Michael Richardson <[email-masked]>, Sandelman Software Works
 -= IPv6 IoT consulting =-

---

From: Brian E Carpenter <[email-masked]>
Date: Thu, 2 Mar 2017 14:07:08 +1300

>      M_REQ_NEG ---------unicast----------------->

Yes, once you have discovered the address. (And discovery is only supposed
to return a global-scope address, typically ULA, except for the special case
where the target is on-link and no global-scope address is available.)

> grasp daemon, not where to find the registration system itself.

Sure. The extra tweak in M_FLOOD is that you MAY attach a specific locator
to the flooded objective, in case you don't want to perform a follow-up
M_REQ_NEG (or M_REQ_SYN).

   Brian