Ray, Thanks for your feedback! You bring up important points. More inline:
I realise the WG is in a hurry, but I think there's some fundamental issues to solve here on sharpening up requirements
That's probably a very valid comment.
if the architecture is going to last more than a couple of years. I really miss a discussion on requirements. I'm probably going to push forward some things you'll say are not typical user requirements and will therefore push back. That's healthy, and we should be very clear about the problem homenet is trying to solve, and what is, and what is not in scope.
OK
If I think of my own house network, I don't think it fits in any of the scenarios in the document today in terms of complexity. That's a bit scary. I have IPv4 from one provider, IPv6 from another, DMZ's for inbound services, multiple firewalls, wireless extenders...... being honest, would your home network fit in with any of the architecture pictures? Or is this wishful thinking of what you think your parents / friends could realistically manage?
I don't think your requirements are that uncommon, I have most of those things, too. Though its not clear to me exactly how that affects the architecture. Wireless extenders are part of L2 that is not usually visible, though the other things are perhaps more visible to l3. Maybe the effects are what we should be talking about in terms of the requirements.
Some major trends in home networking have been hidden from view of the network providers and network equipment prociders, (and perhaps the IETF too) by large scale use of NAT. If you want to get rid of NAT you're going to have to address the following IMVHO. The focus has been largely on the number of devices (address depletion), but the real challenge is likely to be complexity of requirements (IP becomes ubiquitous). 1) I contend that multi-homing is probably going to become the "norm" in Europe by 2022, due to The European Electricity and Gas Directive. That corresponds at least to picture 4, if not more. But that picture seems to presume a single isolation LAN to connect two ISP providers of equal worth. I think that reachability, and cost, and the services provided by the various networks, may be radically different. One may be your entertainment ISP. Another your telephony ISP. Another your electricity provider ISP. Your car may connect to the electricity network ISP to register charging. Your phone may connect to 4G whilst not at home and then to WiFi whilst you are at home, and to hard wired cable when it is connected to its charger. Or perhaps to homenet for controlling the lights and the 4G for voice calls.... We should be clear about what (if any) interaction, provider preference / selection, and fall back scenarios will be implemented as part of the homenet providing an ISP selection function; or whether the service providers should be seen as providing 3 or more logically separate home networks, and where the end device itself has to chose the outbound path independently of the ISP's and homenet(s) routing.
Today's trend is that utility networks are largely independent, parallel networks. That may change, and separate networks may not be the desirable direction. That being said, I'm a bit reluctant to convert the homenet effort into yet another IPv6 multihoming effort. I'm more in the camp that we should document good existing practice for IPv6 home networks, than try to invent lots of new technology. At least on first go.
2) Wireless is exploding. I contend that the single layer LAN in the picture is a non-starter. There is almost certainly going to be at least two short range radio system technologies in home networks: one wifi and one LoWPAN type network for device control.
Yes.
There may be more technologies given the rate electronics is moving at the moment e.g. NFC, networking via LED lighting.
Yep.
So there may also be a requirement for interconnection of multiple ultra-short range networks via a house backbone: e.g. lights on top floor pool to form a mesh network, and lights in the basement form a mesh network, but the reinforced concrete floor partitions the two wireless meshes, so you need a routed connection between them.
I think we do include that already. Its part of being able to provide a routed, multi-subnet network. Precisely for these reasons. (But if you are arguing that we should all use some form of ad hoc routing technology in the entire network, I might disagree because I don't believe those have been shown sufficient deployment experience in the general environment t obe recommended at this time. IMHO, of course.)
The various radio and lightwave standards are unlikely to be L2 bridgeable IMHO. That may add another layer of routing to your picture.
I agree, but I think you may be reading too much into the picture. Lack of ability to do L2 bridging is the primary reason for having multiple subnets.
3) Virtual machines are exploding. I run 4 VM's on my workstation. With the various upcoming application stores and multiple application developers running on one system, I could easily imagine that each application eventually runs in its own mini-VM, so each IPv6 host becomes the equivalent of an old style mainframe with multiple prefixes and intra-machine routing. That may add another layer of routing to your picture. There may also be virtual firewalls between those VM's, which adds another layer.
Yep. I have that in my network, too :-) But the question is, what does it imply in terms of requirements? It at least implies that we need to support many devices, and probably even more reason to allow for additional subnets (e.g., to allow one set of virtual machines exist in their own subnet inside a physical device).
4) IPv4 NAT allows limitless layers of stacking of networks (for outbound connectivity at least) I think stackable devices are going to be important. Why buy a whole new device to support a new wireless technology or WAN technology, rather than just an adapter?
OK, but...
I submit that a more suitable generic architecture picture for homenet would therefore be multiple trees of indeterminate depth of stacked devices, with the ISP router forming the root of each tree network and IPvs end nodes the leaves. This would obviously have major consequences for the requirements of prefix delegation, routing protocol selection etc. You can also argue whether these trees should interact in any intelligent way, or whether the end nodes should be individually multi-homed to several independent trees and thus have to provide any intelligence for ISP selection themselves.
... and I think we definitely agree that any address allocation, discovery, or routing scheme should work at least with trees of indeterminate depth (or perhaps even with more complex topologies). As noted above, I'm a bit hesitant on multihoming though.
Hope this gets the ball rolling, resulting in an architecture with an extended lifespan.
I think it does set the ambition level correctly. Thank you. Jari _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
