[routing-wg] [db-wg] Need for "import-via:" and "export-via:" attributes in AUT-NUM object

On 27/11/2013 17:51, Rob Evans wrote:
>> - The change is backwards compatible with older RPSL parsers. - The
>> new attributes are completely optional. - This change adds advanced
>> functionality that will especially benefit route server operators
>> and participants.
> 
> Can I encourage those that have an opinion about this to voice it?
> The NCC would like some confirmation from the community that there is
> some demand to implement this (and no objection to doing it).

I don't object to this change, and possibly a good purpose will be served
by having it although I don't plan to use it.  By way of historical
context, this syntax was previously implemented about 15 years ago using
the rs-in: and rs-out: statements for the routing arbiter project.  These
parameters were lost in the mists of time, but you can still find traces of
them here and there, e.g.

> http://www.nanog.org/mailinglist/mailarchives/old_archive/1999-10/msg00429.html

My main concern about the changes is that they unearth a more fundamental
problem with rpsl, namely that it is not possible to extend the language
without creating a new incompatible statement fork with duplicated syntax.
 Probably this can be handled relatively efficiently by the back-end code
but from the point of view of language design, it's ugly.

Nick