PeertoPeerNetze

PeertoPeerNetze, or peer-to-peer networks, are distributed computer networks in which peers directly share resources such as bandwidth, storage, or data without relying on a centralized server. Each node can act as both a client and a server, contributing and consuming resources.

Architecture: They can be structured or unstructured. Unstructured networks (as in classic Gnutella or Kad) rely on flooding or random walks for resource discovery, while structured networks use distributed hash tables (DHTs) and predefined routing. BitTorrent exemplifies a hybrid approach with trackers or DHT for peer discovery and piece exchange. NAT traversal, firewalls, and direct connections are central to operation.

Applications: Used for file sharing, software distribution, content delivery, and distributed computing. They enable scalable distribution by spreading load across participating peers. They are also used in blockchain networks for peer discovery and data propagation, and in decentralized storage systems like IPFS.

Benefits and challenges: Benefits include resilience to single points of failure, efficient bandwidth usage, and potential cost savings. Challenges include security risks, such as malware, copyright concerns, privacy issues, and performance variability due to churn and network conditions. Legal and regulatory considerations vary by jurisdiction.

History and examples: Early P2P networks emerged in the late 1990s with unstructured designs (Gnutella) and later scaled with BitTorrent in the early 2000s. Notable implementations include BitTorrent, eDonkey, Kad networks, and IPFS. Ongoing developments focus on decentralized storage, edge computing, and privacy-preserving protocols.