# Navico GoFree: screen-mirroring protocol findings

> Navico GoFree records screen-mirroring protocol behavior observed on a Simrad NSS12 evo3 marine display. It maps UDP multicast discovery at 239.2.1.1:2052, the TCP connection on port 6633 that enables video output, and the RTSP /screenmirror endpoint, with small client probes.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-08
- Original resource: <https://github.com/ThePhantomPuppet/navico-gofree-protocol>
- Primary source: <https://github.com/ThePhantomPuppet/navico-gofree-protocol/blob/0757d0bfc74fe2cd5d7a7f949626c299525be4fb/README.md>
- Catalog page: <https://awesomerea.org/resources/navico-gofree-protocol-case/>
- Record JSON: <https://awesomerea.org/resources/navico-gofree-protocol-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/navico-gofree-protocol-case/index.md)

## Requirements & limits

- **Prerequisites:** Requires a compatible GoFree marine display and access to its Wi-Fi network.
- **Limits:** Observations are primarily from a Simrad NSS12 evo3; behavior on other models needs confirmation.
- **License:** MIT License.

## Primary sources

1. <https://github.com/ThePhantomPuppet/navico-gofree-protocol/blob/0757d0bfc74fe2cd5d7a7f949626c299525be4fb/README.md>
2. <https://github.com/ThePhantomPuppet/navico-gofree-protocol/blob/0757d0bfc74fe2cd5d7a7f949626c299525be4fb/docs/protocol-overview.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.