[lime-users] Routing to the Internet

Hi, I would like to know a bit about the routing protocol, specially when there are several Internet gateways available. I was once told it makes decisions mainly based on packet loss. That sounds good in order to find the best way out to the Internet. But, is there any kind of load-balance system so that every gateway is used according to its capacity? When having multiple Internet gateways, is it a normal scene to have only one active in the whole network? Or it should normally use different gateways at the same time? Besides packet loss, what other criteria are taken into account to make decisions? Cheers!