server/src/main/java/com/orientechnologies/orient/server/OClientConnectionManager.java
public OClientConnection connect(final ONetworkProtocol iProtocol) {

    final OClientConnection connection;

    connection = new OClientConnection(connectionSerial.incrementAndGet(), iProtocol);

    connections.put(connection.getId(), connection);
    OLogManager.instance().config(this, "Remote client connected from: " + connection);
    OServerPluginHelper.invokeHandlerCallbackOnClientConnection(iProtocol.getServer(), connection);
    return connection;
  }
public OClientConnection connect(final ONetworkProtocol iProtocol) {

    final OClientConnection connection;

    connection = new OClientConnection(connectionSerial.incrementAndGet(), iProtocol);

    connections.put(connection.getId(), connection);
    OLogManager.instance().config(this, "Remote client connected from: " + connection);
    OServerPluginHelper.invokeHandlerCallbackOnClientConnection(iProtocol.getServer(), connection);
    return connection;
  }
Create a connection.

@param iProtocol protocol which will be used by connection

@return new connection