[routing-wg] Support for "Publish in Parent" [RPKI RFC 8181]?

Hi working group,

In recent mail threads the concepts of "Hosted RPKI" and "Delegated
RPKI" came up, but as mentioned by Tim and Rubens, another flavor also
exists! A "hybrid" between Delegated and Hosted, informally known as
"publish in parent" (aka RFC 8181 compliant Publication Services).

There are multiple benefits to the general RPKI ecosystem when RIRs and
NIRs support RFC 8181:

    * Resource Holders are relieved from the responsibility to operate
      always online RSYNC and RRDP servers.

    * Reducing the number of Publication servers reduces overall
      resource consumption for Relying Parties. Consolidation of
      Publication Servers improves efficiency and is generally
      considered advantageous.

    * Helps avoid "reinventing the wheel": it might be better to have a
      small group of experts build a globally performant and resillient
      infrastructure that serves everyone, rather than everyone building
      the 'same' infrastructure.

Other RIRs and NIRs are also working on RFC 8181 support. RFC 8181 is
relatively new so it'll take some time before we see universal
availability.

    NIC.BR (available): https://registro.br/tecnologia/numeracao/rpki/
    APNIC (available): https://blog.apnic.net/2020/11/20/apnic-now-supports-rfc-aligned-publish-in-parent-self-hosted-rpki/
    ARIN (planned): https://www.arin.net/participate/community/acsp/suggestions/2020/2020-1/

Is implementing RFC 8181 support something RIPE NCC should add to the
https://www.ripe.net/manage-ips-and-asns/resource-management/rpki/rpki-planning-and-roadmap ?

What do others think?

Kind regards,

Job

Relevant documentation:
https://datatracker.ietf.org/doc/html/rfc8181