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Re: proposed text for charter

Hi Thomas,


El 07/04/2005, a las 16:36, Thomas Narten escribió:

Catching up here...

Charter looks good overall, but it is also daunting... there is a
_lot_ of stuff here....

On one specific point:

o ULIDs will be actual IP addresses, permitting existing applications to
continue to work unchanged, and permitting application referrals to
work, as long as the IP Addresses are available. 

I'm not sure I understand what this means.

what does "as long as the IP Address are available" mean? Is this
trying to say anything other than "if packets can still be sent from A
to B (using whatever addresses happen to work) referrals will also
work"? Or is there some other subtle restriction here?


My understanding is the following:

Suppose that There are 3 nodes, node A with addresses IPA1, IPA2,..., IPAN, node B with IPB and node c with IPC

Now node B is communicating with A. As ULIDs for the communication they are using IPB and IPAj.

so for the communication between A and B if there is a failure in the path associated to IPB and IPAj, the communication can be preserved using alternative locators for node A (assuming both ends support SHIM)

Now, suppose that the application running on A passes as application level information IPAj to an application running on node C.

At this point, node C only has one of the addresses associated with node A, IPAj (the one obtained through the referral).

At this point, if IPAj is unreachable from node C, the communication will fail, because node c has no knowwledge about the alternative locators for node A.

There are possible solutions for this, like using the reverse tree for obtaining alternative addresses for node A (this may have some problems also) or modifying the app so that all addresses are included in the referral (but this needs changing the app of course)

So, i guess that this is what is being expressed in the charter...

Regards, marcelo


Thomas