See the section: "3. Examples of Limited Domain Requirements" ...the problem statement starts by saying that home networks might optimize for "compatibility a

See the section: "3. Examples of Limited Domain Requirements" ...the problem statement starts by saying that home networks might optimize for "compatibility and security by default", whereas a giant CDN might optimize internal traffic for performance and violate some of the general "Internet Protocol" recommendations. That giant CDN's internal traffic might use MANY of traditional IP protocol components, but might not be fully compatible with "the open internet" for a variety of reasons. """Nevertheless, because of the diversity of limited domains with specific requirements that is now emerging, specific standards (and ad hoc standards) will probably emerge for different types of domains. There will be attempts to capture each market sector, but the market will demand standardized solutions within each sector. In addition, operational choices will be made that can in fact only work within a limited domain. The history of RSVP [RFC2205] illustrates that a standard defined as if it could work over the open Internet might not in fact do so. In general, we can no longer assume that a protocol designed according to classical Internet guidelines will in fact work reliably across the network as a whole. However, the "open Internet" must remain as the universal method of interconnection. Reconciling these two aspects is a major challenge.""" ...the underlying point is that the internet is fragmenting (home != open, cdn != open, home != cdn), and they're calling it out as a RFC... stating the problem. Their recommendation (towards the end) alludes to tagging / nesting of networking groups. (see: "With this perspective, we can list some general functional requirements.") Whether a node "IN" or "OUT" of a "LIMITED DOMAIN" is a signal that is useful to know (probably either to restrict or allow traffic in and out of a particular domain). There are definitely some valid points in there, but it's also possible to take a very dystopian/pessimistic view as to what this allows. The Good? A local wifi in your car with special rules, hardware, or protocols might be super cool! ...especially if it's compatible with other "CarWiFi(TM)" networks. Same goes for "CDN-Net9000gb(TM)". The Bad? Those same tools could be very effectively used at political, not just technical boundaries. "US-Net", "China-Net", etc. with varying degrees of compatibility or access between them.