The high-level protocol used in a peer-to-peer network. Peer-to-peer protocols are typically application-level protocols (see
OSI model). Gnutella and Kazaa are examples of peer-to-peer file sharing protocols. SIP and Skype are examples of voice over IP (VoIP) protocols. In the crypto world, the blockchain protocol is a peer-to-peer protocol that includes other functionality (see
consensus mechanism). See
peer-to-peer network,
SIP and
Skype.