Hello Mark :
>The majority of IP-based home networks today are neither power-constrained nor >particularly lossy. So, while we can certainly learn from LLN requirements >analysis, I do think the base requirements in homenet could turn out to be >quite different, or at least a smaller and slightly different subset, of the >overall LLN requirements. > Certainly, home networks have an emerging IP-based "low power and lossy" > component in them. One could even argue that it will become dominant at some > time in the future, but that's a leap I personally would be pretty > uncomfortable in the group making without some very strong data to back it up. In any case we have to consider the integration of the LLN (e.g. a Command and Control) component of the network within the HOMENET architecture, wouldn't you think? If so, there is a probably a RPL piece to the story, and the question becomes how that piece integrates with the rest of the architecture. We probably want to obtain a converged network, and probably would prefer to avoid running too many routing protocols, with redistribution policies etc... which can rapidly become nasty in terms of administration. Anyway, I'd suggest that whether the home network is fully an LLN or not is not necessarily the core if the RPL applicability discussion: * ROLL did not produce a routing protocol that is limited to LLNs, but a routing protocol that is acceptable for LLNs. IOW it is not restricted to LLNs, by far. * RPL is designed to be simple to deploy. It inherits from mesh technologies the traditional self-* properties which make it quite autonomic thus better fit for unmanaged environments. * RPL is designed and optimized for edge (stub) networks, with one or multiple gateway. Just like L2 mesh networks, RPL builds multilink nets and/or subnets that are oriented towards the gateways. It is possible to optimize traffic from/to certain destinations within the network, but the general goal is NOT any to any optimization. As a result, it can be desirable to have a non-RPL high speed backbone that can be a single backbone link or that can be a more complex IPv6 backbone network running, say, a link state protocol, when that's really needed. * Associated to the support of multiple gateways, RPL incorporates natively the concept of multiple routing topologies, for instance if you want to separate a metering network that reports to some utility with your voice and video network. This comes with 6MAN drafts that enable to tag the packets so as to follow the appropriate topology. * Finally, the brains for the routing decision is a plug in, called an objective function (OF). So even if HOMENET inherits from ROLL for the DV loop avoidance scheme and from 6MAN for the tagging/forwarding, the WG can still define one or more OFs that will dictate the shape of the resulting routing topologies. The OF is the decision maker that will, say, prefer a high speed Ethernet over an LLN, for a given class of traffic. What do you think? Pascal _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
