Hi Anders:
There are a number of requirement drafts for this and that. I think Julien and Mathilde tried to compile at some point what the arch minimum would be in a device to run IPv6 and looks OK. The recent developments are that people tend to think that you can live with an IPv6 derived from the MAC address without any DAD. But you'd still need the prefix information that's found in the RA-PIO and the routing information that's found in the RA-RIO (that's very much like RPL 08's DPO). So you see, it is actually very useful to RPL routers to carry those RA options unchanged within RPL's DIO Current ND is the de facto abstraction for the host interface. Some LLN/LoWPANs bring in a number of new concepts from route over. And now we're wondering what's the position of ND in that world. At one extreme we could say that the route over piece is a router problem and externalize it from ND unto RPL and such. At the other, we could consider that RPL is actually the component of ND that handles router to router. Why not after all? Cheers, Pascal From: [email protected] [mailto:[email protected]] On Behalf Of Anders Brandt Sent: Friday, May 07, 2010 9:03 AM To: Kris Pister Cc: ROLL WG; [email protected] Subject: Re: [6lowpan] [Roll] how does a node get an IPaddress Kris, > But it's not a power issue Agreed. This was meant to be an example only ;-) - Anders ________________________________ From: Kris Pister [mailto:[email protected]] Sent: Thursday, May 06, 2010 23:27 To: Anders Brandt Cc: ROLL WG; [email protected] Subject: Re: [Roll] [6lowpan] how does a node get an IPaddress Anders - there are many commercial networks (even in buildings and homes) where battery operated nodes are routers. I don't think that we should confuse the line/battery power issue with the host/router issue. There are many reasons why a node might choose or be designated to be a host not a router, so your question still stands. But it's not a power issue. ksjp Anders Brandt wrote: Let me try one more time: How much of this will I have to implement to be compliant with other LLN/RPL nodes? In a home control/building environment, the notion of a router nodes is rather artificial. I may have _host_nodes_. They are host nodes because they are sleeping (battery operated) and therefore they cannot participate in routing. They still have to get an IP address to talk to other IP hosts. Alternatively, I may have combined _host&router_nodes_ which serve a purpose application-wise and at the same time happen to be routing resources. Do these hosts have to use another way of getting IP addresses just because they happen to be able to do routing? From a designer's standpoint it does not seem quite elegant that I have to do use different methods depending on the power model for my node. Am I missing something here? Thanks, Anders -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Carsten Bormann Sent: Thursday, May 06, 2010 10:04 To: Pascal Thubert (pthubert) Cc: ROLL WG; [email protected]; [email protected] Subject: [6lowpan] RPL aware hosts (Re: [Roll] how does a node get an IPaddress) On May 6, 2010, at 09:02, Pascal Thubert (pthubert) wrote: enable RPL aware hosts Should we? (Obviously, if a node really needs to know about RPL, it can always become a router.) If I understand you correctly, this is about hosts selecting a specific RPL instance-ID for outgoing traffic. Traditionally, IP has used the TOS byte (Traffic Class in IPv6) to select between different behaviors of the forwarding system. What is it that the host wants to say by selecting a specific RPL instance ID? Why can't the router make that selection, e.g. based on the Traffic Class and the destination address? (Another interesting question is, for incoming traffic, how a host selects which instances it wants to be part of. Is that even a useful thing to do? Would that selection be made by the host, by its first-hop router, or by some configuration agent?) It would be useful to get more information about how instance-IDs are intended to be used with RPL. On the protocol side: If there really is something that a host needs to know about RPL-specific information (instances or whatever), this could be delivered in an ND option that could very well be defined in an RPL-related document, no need to define it in 6LoWPAN-ND. Another way to set up this information would be to configure it during commissioning or using a host configuration protocol like DHCP. Gruesse, Carsten _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ Roll mailing list [email protected] https://www.ietf.org/mailman/listinfo/roll
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