Subject: Re: [lisp] lisp Digest, Vol 14, Issue 5

From: "Sriram, Kotikalapudi" <[email-masked]>
Date: Thu, 7 Jan 2010 15:57:20 -0500

Some comments inline below.
Sriram
http://www.antd.nist.gov/~ksriram/ 

> 
> Message: 1
> Date: Thu,  7 Jan 2010 10:46:58 -0500 (EST)
> From: [email-masked] (Noel Chiappa)
> Subject: Re: [lisp] Design discussion -06-(3) -> return all
> 	overlapping	prefixes
> To: [email-masked]
> Cc: [email-masked]
> Message-ID: <[email-masked]>
> 
>     > From: "Joel M. Halpern" <[email-masked]>

--- snip -----------
>     > We are talking about overlapping EIDs, not overlapping locators.
>     > There are LOTs of overlapping addresses in the current tables.
>     > There are multiple reasons for these.
>     > It is not clear to me that any of them apply to EIDs.
> 
> Good point. A list of uses for overlapping EIDs would be a good input to
> the decision below, but...
> 
> 
>     > an interesting idea for how one might use overlapping EIDs if they
>     > are allowed. That usage clearly has value. Is that value more than
>     > the complexity required for allowing overlapping EIDs?

The proposal summary document that I submitted to the RRG list recently
identifies some use cases for overlapping EIDs.
http://www.ietf.org/mail-archive/web/rrg/current/msg05541.html 
(We may have come at this from a different angle though --
trying to preserve EID aggregation and reducing processing
and memory requirements related to mapping distribution.)

For more details, please take a look at the cited document/slides: 
http://www.antd.nist.gov/~ksriram/NGRA_map_mgmt.pdf
http://www.antd.nist.gov/~ksriram/MDP_Dublin_KS_Slides.pdf
(Presented at the Dublin RRG meeting in 2008)

--- snip -----------
> 
>     > Particularly if, as appears to be the case, we would need to
>     > indicate that any request for a block that has nested EIDs needs to
>     > return all those nested EID mappings as well?
> 
> This is the other main facet, a thorough understanding of the engineering
> implications (and choices) - and it's the one I most don't understand well
> yet.
> 

We grappled with this issue as well in the documents cited above --
how to manage/optimize mapping messages when you have nested EIDs. 

--- snip -----------