Ultrapeers and leaves
 

Hi All,
I have a question about the Gnutella06 protocol. LimeWire introduced the Ultrapeer-leaf model to organize Gnutella peers into 2 hierarchy. This seems to be a good invention because it addressed the problem of heterogeneous nature of peers, delegate work according to one's capacity, and limited the message flooding. (especially avoided overloading low-capacity nodes with too many msg). I am just wondering, how does a leaf node choose its Ultrapeer? Is it relatively static (a particular leaf node is likely to get the same ultrapeer very time) or is it purely dynamic(decided rather randomly). Do you have any thought or comment about Ultrapeer/leaf convention?
THanks,

Correct me if I'm wrong, but I think ultrapeers are chosen randomly, just like normal nodes were chosen randomly. I think gnutella host caches also cache ultrapeers, but I'm not sure about that and I'm not sure whether ultrapeers are marked as ultrapeers when returned from the cache.

Ultrapeers are not chosen randomly, - if you have a certain connection speed and a certain average uptime, then you will become an ultrapeer if you try connecting to an ultrapeer that says that it doesn't have enough free leaf slots anymore.

Clearly, the servent software can decide whether the own node is ultrapeer-capable depending on the available bandwidth, CPU power etc., and this capability is (more or less) static.

But the question from lut321 was how ultrapeers to connect to are chosen, not whether the own node is an ultrapeer or not.

Well that depends on the client and you may ask this question in the GDF...
As far as I can say Darkalien, the client we're working on, is just selecting peers to connect randomly, same for UPs since you can see if you are connecting with an UP only while handshaking, eh?

Right, but it may be that the Gnutella host cache servers also return the types of the nodes (leaf, ultrapeer, normal), but I don't know if this is the case.

They can return the speed but not the type

They don't return the type because leafs do not submit their address to the caches. With normal peers almost extinct, it SHOULD be a pretty good bet that the address you receive from the cache is an ultrapeer.