4.1 Establishing a Connection

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Node 2 wants to connect to a graph previously created by Node 1. Node 1 is already listening for incoming connections, and its address and port are known by Node 2. Node 2 has never connected to the graph before.

Example of a message exchange when connecting to a graph

Figure 5: Example of a message exchange when connecting to a graph

To establish the connection, the following steps occur:

  • Node 2 establishes a TCP connection to Node 1.

  • Node 2 sends an AUTH_INFO message to Node 1. Because this graph is not using a graph security provider, authentication is complete without any additional messages.

  • Node 2 sends a CONNECT message to Node 1. Node 2 is not yet listening, so no addresses are contained in the CONNECT message.

  • Node 1 has no other connections (and, thus, has not reached its maximum neighbor count), so it accepts the new neighbor connection. In response, Node 1 sends a WELCOME message to Node 2.