Re: [DNA] Possible way forward: combining Link ID and Landmark?

[Syam Madanapalli <smadanapalli@gmail.com>]

Hi Pekka,

We need to use linkid for its robustness against 
changes in linkid due to prefix addition/deletion,
landmark to benifit for nodes moving from non-DNA
to DNA link, complete RA to build the CPL fast for
fast moving nodes. And also it may be good to use
Landmark YES answer and to avoid the periodic
complete RA to save the bandwidth (use linkid).

So I am thinking about the following solution.

1. On DNA links routers advertise linkid in RAs.

2. A node with Link_Up sends an RS with landmark,
   if the landmark presents, the router sends an 
   RA with linkid.

   The other alternative is to send YES answer.

3. If the Landmark does not present, it sends a
   complete RA with linkid (i.e. I bit set for one
   of the prefixes)

4. If no linkid present (moving from non-DNA to DNA link)
   the node picks one of the prefixes as the landmark.

The complete RA is sent only when there is a link change.


-Syam

PS: are we over engineering?


On 8/8/05, Pekka Nikander <pekka.nikander@nomadiclab.com> wrote:
> [As I wrote earlier, I haven't been able to follow the ML discussion,
> and won't.  My sincere apologies.]
> 
> Based on what I heard during the WG meeting on Thursday and in some
> discussions afterwards, the following proposal occurred to me.  It
> may be completely off the mark.  If so, please ignore it.  I am
> offering this just in the case it might be useful and let the WG to
> move forward.
> 
> Would the following work?
> 
>   1. Define a new Link ID RA option, as in the Link ID draft.
> 
>   2. Define new Landmark RS and RA options, as in the landmark draft.
> 
>   3. Routers in a link are encouraged to create a Link ID and
> announce it, but not required.  [Details need to be filled in, e.g.,
> if all routers need to agree etc.]
> 
>   4a. A host that arrives on a link *with* a Link ID picks the Link
> ID as its landmark.
> 
>   4b. A host that arrives on a link *without* a Link ID picks one of
> the prefixes as a landmark, just as in the current landmark draft.
> 
>   5. When a host detects that it may have changed links, it looks
> for a landmark (as in the landmark draft) unless it gets a Link ID
> (as the landmark) very quickly (as in the case of FastRA-like
> optimisation).
> 
> Based on my very partial understanding, the above outline might
> work.  However, it may also be more expensive (in term of bytes or
> packets) than the current proposals.  On the other hand, it might
> also be more flexible or robust.
> 
> Maybe someone could do further thinking and analysis.
> 
> --Pekka
> 
>