On Thu, Nov 23, 2006 at 10:16:11PM -0800, philions philions wrote: > There is one thing recently haunting me, how many mobile devices a home > agent can support in general, 'support' here means home agent can > successfully handle requests from mobile devices for update binding, process > and transfer packets to and from mobile devices on condition that home agent > act as medium for communication between mobile devices and corresponding > nodes.
Hi, Let's look at some design issues. Binding cache is a hash table with linked lists for collisions. There's 32 buckets and hash collisions should be pretty evenly distributed. When the number of bindings grows, the number of hash collisions also grows and linked lists may become a issue. You can increase the number of hash buckets. Or you can replace the whole hash table with e.g. Patricia trie. This is probably your last problem, though. :) I don't know if the number of network devices is limited in Linux or not. If it is, that would certainly put an upper limit to number of tunnels. Of course, there are memory limitations (bindings take up memory both in kernel and user space), but these are dependent on the machine running the HA. Also, HA starts a short lived (seconds) thread for a BU, so if you would dump, let's say, a million valid BUs on the HA in one second, the HA would probably run out of memory. But the biggest problem in your case (without route optimization) is the data traffic. It is highly dependent on the amount of traffic passing through HA. I would guess it is pretty easy to choke a HA (using 1Mbps link) with 1000 MNs streaming video without route optimization, while with a 10Gbps link the HA might hardly notice it. But obviously, it is the same thing for any router. There's also a number of other points where performance could be an issue, e.g. IPsec, XFRM. I do not know enough of those to even have a valid guess, though. Some performance measurements should be done, if you want to look at those. Regards, Antti _______________________________________________ mipl mailing list [email protected] http://www.mobile-ipv6.org/cgi-bin/mailman/listinfo/mipl
