We had a not-long-enough chat with Mitar and Jernej yesterday about roaming. Here's a quick summary and some ideas.
Wlan-SI are deploying a massive infrastructure across all of Slovenia and parts of neighbouring countries. They achieve multihoming by tunnelling to a central server, so no source-specific routing is required. They're currently using OLSRv1, but are in the process of transitioning to Babel. Hosts are not participating in the routing protocol, they use traditional DHCPv4/RA on their access points. Since they need to scale to thousands of routers (and probably tens of thousands of hosts), using a single L2 domain won't work for them. However, they would still like to have roaming support -- the typical use case being a large house with multiple access points. If I understood correctly, they're not trying to support wide-scale roaming -- the roaming domains will be small and well-defined. After some discussion, we agreed that Mikrotik's solution to this problem, while inefficient, is quite reasonable: they're bridging the interfaces in a home using "EoIP", which is just Ethernet over GRE over IP. Since the encapsulation will be local to the home, the resulting fragmentation should not be a serious problem. Mitar indicates that they have high-speed links, which precludes userspace forwarding. A quick web search indicates that Ethernet over GRE is supported by the Linux kernel as "gretap". I have no idea whether this is the same as RFC 3378, and I don't know whether it would be preferable to use the softwires standards. For the longer term, we should be looking at pure layer 3 roaming solutions, at least for IPv6, since that would allow roaming at a global scale. The simple solution would be to run Babel on the host (which implies rooting Android phones, unfortunately). I have no experience with Mobile IPv6, and don't know whether it's implemented. -- Juliusz _______________________________________________ Babel-users mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/babel-users
