p2p

P2P

This package provides an interface for peer-to-peer networking features, such as peer identification, addressing, connectivity, messaging, custom protocol streams, and peer discovery. These features are implemented using libp2p, and this package and its sub-packages serve as the main integration point with libp2p.

The code in this package is part of an ongoing initiative to research and implement an alternative networking stack that supports decentralized network topologies, while benefiting from the history and experience of libp2p's protocol development.

The current status of this initiative is purely experimental, and is not enabled by default or recommended for regular use. The components implemented here offer no guarantee of security, reliability, or performance. Updates will be provided on the progress and readiness of these components for standard usage in the future.

Background

Decentralized networks depend on mechanisms for discovering other peers and reliably broadcasting messages to other interested peers. Libp2p provides pluggable transports and multiplexing to allow multiple stream-based protocols to share the same connection. Libp2p also provides an implementation of a message-based gossip protocol, GossipSub.

Algorand's current network protocol sends messages between peers over bidirectional WebSocket connections. Nodes that are configured to enable message-forwarding (including nodes currently called "relays") validate incoming messages, then selectively forward messages to other connected peers. This network implementation (WebsocketNetwork) sits behind the GossipNode interface in the network package.

Current P2P implementation details

This package supports a P2PNetwork implementation of the GossipNode interface, providing the same peer connection management and message broadcast functions, but via peer connections managed by libp2p. The P2PNetwork implementation uses libp2p's multiaddress scheme and peer IDs to establish connections and identify peers.

Currently transactions (protocol tag TX) are distributed using the GossipSub protocol, while all other messages are forwarded over a custom message protocol /algorand-ws/1.0.0 that uses the same message serialization as the existing WebsocketNetwork implementation. These two protocols are multiplexed over a single connection using libp2p streams.

graph LR
    subgraph "P2P Implementation"
        P2P[P2PNetwork]
        TX[Transactions]
        AW[Other messages]
    end
    P2P --> TX
    P2P --> AW

    subgraph "libp2p"
        G["GossipSub 1.1<br/>/meshsub/1.1.0"]
        WS["Legacy message serialization<br/>/algorand-ws/1.0.0"]
        S["Multiplexer<br/>/yamux/1.0.0"]
        T["TCP Transport"]
    end
    G --> S
    WS --> S
    TX --> G
    AW --> WS
    S --> T