2010/2/12 ilter yüksel <[email protected]>: > Hello, > > For exit router selection path-spec says that; > > "For circuits that do not need to be "fast", when choosing among multiple > candidates for a path element, we choose randomly. For "fast" circuits, we > pick a given router as an exit with probability proportional to its > bandwidth." > > Could anybody explain why Tor pick exit router with probability proportional > to its bandwidth only for fast circuits? As far as i know Tor uses this > technique for load-balance. But why it uses this technique only for fast > circuits?
First of all, "Fast" circuits are a bit misnamed as used in path-spec.txt. Basically, "fast" means "bandwidth-sensitive". The only ones that aren't don't need to be "fast" in this sense are ones that are going to be used only for a tiny amount of traffic. That said, I think the statement in path-spec.txt may be poor. It probably makes sense to weight all choices by bandwidth, now that bandwidth is measured rather than just being self-advertised. To see what the code is actually doing, the string to search for is need_capacity or NEED_CAPACITY. The most interesting layer to look for this is at is where it's passed as a flag to circuit_launch_by_router() or circuit_launch_by_extend_info(). -- Nick *********************************************************************** To unsubscribe, send an e-mail to [email protected] with unsubscribe or-talk in the body. http://archives.seul.org/or/talk/
