Signaling Server
The small coordination service peers use to find each other before connecting directly.
A signaling server relays the messages two peers need to exchange in order to establish a direct connection: session descriptions and candidate network paths. Once the connection exists, it carries no further traffic.
It is the irreducible center of an otherwise decentralized design. Peers cannot discover each other from nothing, so something must introduce them — and that something is a server, however small. Recognizing this early prevents a lot of disappointment about how serverless a peer-to-peer architecture really is.
Its saving grace is that it is genuinely small. It holds no application state, stores nothing durable, and handles a message or two per connection. It can be a few dozen lines, it scales trivially, and it can be run on the cheapest infrastructure available.
Two design consequences follow. Room identity is signaling's concern: peers find each other by agreeing on a name, which is why URL-slug lobbies are the natural pattern — the address is the coordination, with no accounts required. And signaling availability is application availability: if the server is unreachable, nobody connects, so surfacing that state honestly is part of the design rather than an edge case.
See also3
WebRTC
The browser standard for direct peer connections carrying audio, video, and arbitrary data.
Networks & Distribution12 connections
Peer-to-Peer
An architecture where participants communicate directly rather than through a central server.
Networks & Distribution11 connections
Conflict-Free Replicated Data Type
A data structure whose replicas can be edited independently and always converge without coordination.
Networks & Distribution7 connections
Related3
Nearby in the graph rather than deliberately chosen. Looser, sometimes surprising.
Linked from7
- Conflict-Free Replicated Data TypeNetworks & Distribution
A data structure whose replicas can be edited independently and always converge without coordination.
- Eventual ConsistencyNetworks & Distribution
A guarantee that replicas converge given no further updates, without guaranteeing when.
- IdempotenceSystems & Tooling
The property that performing an operation twice has the same effect as performing it once.
- NAT TraversalNetworks & Distribution
NAT traversal is the set of tricks two devices behind separate routers use to open a direct connection anyway.
- Peer-to-PeerNetworks & Distribution
An architecture where participants communicate directly rather than through a central server.
- Virtual Private NetworkNetworks & Distribution
An encrypted tunnel that presents a remote network as local, and the narrow set of things a commercial one actually hides.
- WebRTCNetworks & Distribution
The browser standard for direct peer connections carrying audio, video, and arbitrary data.