There are three ways to connect to the BDN, each of which requires you to register an account.
Run a Gateway with a node
Run a Hosted Gateway with a node
Cloud-API (connect without a node)
Gateways peer with your node and propagate both blocks and transaction fast to your node. You can also subscribe to Transaction Streaming to receive a stream of new transactions that have been added to the TxPool and a stream of new transactions seen in the BDN. To install a Gateway, please follow the instructions available here.
Running to a Hosted Gateway is similar to running a Gateway, yet the convenience is you do not need to host and manage the Gateway locally.
To connect to a Hosted Gateway, please follow the instructions available here.
Cloud-API supports sending Ethereum transactions fast and subscribing to Transaction Streaming.