Someone has just reminded me Ixel that the Firebricks sit at both ends of an AAISP connection for aggregation - thats how they aggregate it to a single IP address via two backhauls for others who really aren't getting this.
I suspect that's correct, Rizla. For downstream, there is a box in the A&A network that maps a single IPvx address to a bundle of pipes and weighted round-robins the traffic. My firebrick picks this all up and merges the outputs of the three pipes (so for example giving one triple-speed d/s TCP stream) pouting the whole lot onto the LAN. The weighting is informed by the speed reports that BT, say, give out as needed concerning each line.
For upstream, my firebrick does the same in reverse, taking the stream of outgoing IP packets from a single LAN host and distributing them across the outbound pipes. For u/s, it needs to be told what the speeds of the different pipes u/s are. This is difficult as it could change, though luckily it doesn't. My three modems can give me their u/s speeds, which _do_ differ.
The bit about a firebrick at the AA end is informed supposition, based on the availability of high end Firebricks plus various comments made. The box, whatever it is, does all the same things my Firebrick does. Plus things like giving out a pcap, using data over PPP LCP optionally, I believe ISP-end firewalling is an option too for users in trouble,
