GTP peers

I've just noticed that my code cannot handle the same GSN's Ctrl address handing out differing User plane addresses to various other GSNs. That's the point of load balancing, after all. So far I've paired up a Ctrl and a User peer 1:1, that won't do. That and the reply-to-same-port will make the structures a bit more complex still: - Each User address has its one managing Ctrl address, but the same Ctrl address may be used for several User addresses. - One address can have several ports, and a sequence number that came from a given port should get its reply with the same sequence number back to that port (discussion pending?). ~Neels