Hi!

I'm currently working on ultrapeer support in mutella and it's not entirely clear to me when shall the client promote itself from being a leaf to the ultra-node. And when shall it downgrade itself back...

Another question: what are the typical bandwidth requirements for a typical ultrapeer? 20kbps? 30? 100? Or at wich line speed it makes sense to promote? Is DSL enough?

regards,
Max

Usually it should be 1024 kbps and good processing abilities (1 GHz and faster).

well, processing power is cheap these days, 1GHz is not going to surprise anyone... however, the requirement of 128 kilobytes per second dedicated to gnutella connections only is somewhat impressive... No surprise, I couldn't get mutella in superpeer mode to hold connections for longer periods of time with 30-40 Kbytes per second total connection bandwidth limit...

Your client could use these variables when deciding the suitability for Ultrapeer mode:

Bandwidth capacity: at least 256kbps in both directions, dedicated only for hosts traffic, for example
Uptime (average, for a week(?) long perioid): Couple of hours minimum
CPU power and RAM: Depends on the optimization of your client
OS type: Win9x nor old MacOS systems should not be promoted to ultrapeer mode. Generally all OSes which lack in TCP performance should remain in Leaf mode.
Horizon: If host fails to maintain proper horizon, it could demote back to leaf mode
Demand for UPs: If most of UPs in the horizon are full, you could be promoted easily to Ultrapeer and vice versa.

There's a couple of suggestions... The more varialbes you take account when deciding the proper mode, the more scalable will your client be when the network grows and the better will the network work. Also, good target would be to maintain the selected mode long enough. The more stable the network is, the better performance will it have.