Subject: RE: [nemo] Re: Question-HAHA

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Mon, 19 Apr 2004 09:12:28 +0100

You may want to give a look at the appendix in the HAHA protocol. 

For the global HA distribution, there is an overall aggregation of all
MNPs that is advertised by all HAs, wherever they are (they are not
expected to be on a same link) to the infrastructure (the internet). So
all the MNPs are 'topologically correct' at any of the HA regarding the
external infrastructure.

Then the HAs are cross connected with a mesh of tunnels, over which they
run HAHA, in order to distribute a finer granularity of routes. The MNPs
are partitioned in smaller aggregations that belong to a given home
link, which aggregation is advertised by HAs to other HAs using HAHA. If
a MRs binds to its normal HA, the HA does not need to reinject the MNP
routes to the other HAs because the MNP belongs to the aggregation that
it already advertises.

By if a foreign MR binds a foreign MNP to the HA, then the HA needs to
reinject the MNP granularity over HAHA, long as the binding stands. If
the MR uses an MNP address to bind, it does not need to recomputed a
Home Address, but if it uses a home link address, then it needs to
compute it from the prefix on the new home link.

For end to end communications, the MR has to choose between it's careof,
it's home address and its address on MNP. We already discussed the
heuristics for that choice. The MNP based address is the longest lasting
one, but it's also the most costly in terms of path (hops).

LFN communication should not be interrupted but for the duration of the
BU and then the MNP route redistribution between HAs.

Pascal

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf Of
Alexandru Petrescu
> Sent: vendredi 16 avril 2004 23:30
> To: Jee J.Z.
> Cc: [email-masked]
> Subject: Re: [nemo] Re: Question-HAHA
> 
> Jee J.Z. wrote:
> >> Pascal Thubert (pthubert) wrote:
> >>
> >>> It depends on the model. If the MR takes its home address from
> >>> its MNP then it does not need to. If the Home address is from a
> >>> home link, then it needs to change if it takes a home agent on a
> >>>  different home link. This may happen in the case of Home Agent
> >>> Global Distribution with the HAHA protocol.
> >>
> >> Right, and in all the above cases all app->level communications
> >> running on MR or LFN will be interrupted when MR >changes its HA,
> >> right?
> >
> > Why will all communications (running on MR or LFN) be interrupted in
> >  the first case (the MR does not need to change its home address)?
> 
> Because one can not have the same Home Address topologically correct
at
> two different Home Agents that sit on different links (links separated
> by routers), right?
> 
> > Moreover, in the second case (the MR needs to change its home
> > address), why will communications running on LFN be interrupted?
> 
> Because the address of the LFN is derived from a prefix that is
> topologically correct at only one HA, and that prefix can not be
> topologically correct at another HA that sits on a different link
(links
> separated by routers), right?
> 
> On another hand, if it is assumed somehow that a MNP prefix or a Home
> Address can be made topologically correct at two distinct places in
the
> network mesh (like with multi-homing or something) then no Mobile IPv6
> is needed at all to tunnel traffic from a Home Address to a Care-of
> Address, because the Care-of Address is, in fact, the Home Address
> itself that was made topologically correct everywhere, no?
> 
> Alex