The Ocean Protocol v0.9 (Trilobite) Testnet is an Ethereum [Proof-of-Authority (PoA) network](https://wiki.parity.io/Proof-of-Authority-Chains) where all the nodes (Keeper nodes) are running [Parity Ethereum](https://www.parity.io/ethereum/).
There are two kinds of Keeper nodes in the Trilobite Testnet: authority nodes (voting nodes) and user nodes (non-voting nodes).
Authority nodes have a say in determining which transactions are valid. _In the Trilobite Testnet_, the authority nodes are run by BigchainDB GmbH and its partners. If you're interested in running an authority node in the Trilobite Testnet, then email <ahref="mailto:contact@oceanprotocol.com">contact@oceanprotocol.com</a>.
Anyone can run a user node. It will stay in sync with the other nodes in the Trilobite Testnet, it just won't have a say on whether transactions are valid.
Marketplaces and publishers should run user nodes.
See the pages for [marketplaces](/setup/marketplace/) and [publishers](/setup/publisher/).
