TcpCommunicationSpi is default communication SPI which uses TCP/IP protocol and Java NIO to communicate with other nodes.
At startup, this SPI tries to start listening to local port specified by LocalPort property. If local port is occupied, then SPI will automatically increment the port number until it can successfully bind for listening. LocalPortRange configuration parameter controls maximum number of ports that SPI will try before it fails. Port range comes very handy when starting multiple grid nodes on the same machine or even in the same VM. In this case all nodes can be brought up without a single change in configuration.