Just a side note. I haven't read the gnutella protocol yet - btu feel like I should comment on your post.

It the protocol both implementes TTL and HOP and TTL is decremented by 1 each HOP and HOP incremented... what's the use of TTL then?

TTL usually is a value in seconds and thereby relative to the package timestamp of sending.

The HOP should be sufficient for this use. Not to have clients search infinite and or make crazy round trips.

Maybe I have misunderstood the concept you just explained... if so - sorry for taking up your time

// A-Vizion