pm/FURPS.md

# Waku FURPS

- 🏗️: New planned property, yet to be delivered.
- (Vac-DST): Simulations to verify this property
- (Vac-QA): Additional test coverage by Vac-QA to verify this property

## Core Protocols

### Light Push

#### Functionality

1. Enables light nodes to push messages to service nodes for relay to the network.
2. Requests service nodes to publish messages to WAKU2-RELAY pubsub-topics.
3. Provides confirmation that a message has been received by at least one node.
4. 🏗️ Supports comprehensive error codes for various failure scenarios.

#### Usability

1. Implements simple async request/response pattern.
2. Uses standard Waku Message format.
3. Only requires an established libp2p connection.
4. 🏗️ Provides descriptive error messages in responses.

#### Reliability

1. Implements retransmission on failure with exponential backoff.
2. Implements DoS protection through request rate limitation.
3. 🏗️ Status codes indicate the best recovery method (retry, discard service node or irrecoverable failure).
4. 🏗️ 80% message transmission success rate on live Status network (service node from both Status Desktop and fleet Waku instances)
 
#### Performance

1. Only one network round trip is required for operation; including both configuration and message transmission.
2. Minimizes protocol overhead for efficient resource usage.

#### Supportability

1. Linux amd64 CLI as service node
2. Browser as client

### Store

#### Functionality

1. Provides historical message retrieval from the Waku network, enabling nodes to query for messages they missed while offline.
2. Supports multiple query types: time-based, content-topic filtered, and message hash lookups.
3. Enables message presence verification without retrieving full message content.
4. Supports pagination for efficient retrieval of large message sets, and resuming retrieval after disconnection.
5. Supports comprehensive error codes for various failure scenarios.
6. 🏗️ Industry practices are applied to PostgreSQL setup to reach appropriate performance

### Usability

1. Implements simple async request/response pattern.
2. Uses standard Waku Message format.
3. Only requires an established libp2p connection.
4. Provides descriptive error messages in responses.
5. Supports query filtering to retrieve only relevant messages by content topic.

#### Reliability

1. Implements DoS protection through request rate limitation.
2. (limitation) No guarantees in terms of message presence or retention duration.
3. Store node always provide a response; thanks to DoS protection.

#### Performance

1. Only one network round trip is required for operation; including both configuration and message retrieval.
2. Implements pagination to manage resource usage on both client and server.
3. Allows presence queries to verify message existence without transferring full content.
4. Targets query response times under 2 seconds for typical requests.
5. 🏗️ Hash query of less than 10 hashes are served under 400ms; for a database less than 250 GB size and average message size under 500KiB **(Vac-DST)**.
6. 🏗️ Time range queries of less than 24 hours, with less than 10 content topics, are served under 400 ms; for a database less than 250 GB size and average message size under 500KiB **(Vac-DST)**.

#### Supportability

1. Linux amd64 CLI as service node
2. PostgreSQL as database engine.
3. Browser support as client.

## Application Protocols

### P2P Reliability

#### Functionality

1. Improves probability of message propagation through redundant publishing and receiving.
2. Enables detection and remedy of message losses between peers using Store or Filter based reliability strategies.
3. Enhances Lightpush reliability through service node pooling, redundant publishing, and failure detection.
4. Improves Filter reliability through redundant subscriptions and subscription health monitoring.

#### Usability

1. Provides feedback on message delivery status leveraging store protocol.
2. Automatically handles reconnection and retransmission when failures are detected.

#### Reliability

TBD

#### Performance

TBD

#### Supportability

1. 🏗️ Within browser environments (edge node mode)
2. Integrated in Status applications