How are Gnutella ultrapeers centralized? Nodes self-promote themselves to ultrapeers if they meet uptime and resource availability requirements. It's a mechan

How are Gnutella ultrapeers centralized? Nodes self-promote themselves to ultrapeers if they meet uptime and resource availability requirements. It's a mechanism to allow low-spec'd peers to participate without getting crushed with traffic, and also an optimization to reduce churn in the routing tables. The ultrapeers are just long-uptime regular peers.