For a better understanding of how packets and data streams operate over a distributed system, check out Packet Analysis with Wireshark, Anish Nath, Packt Publishing, here: https://www.packtpub.com/networking-and-servers/packet-analysis-wireshark.
For a closer look at data streams in practice, consider Stream Analytics with Microsoft Azure, Anindita Basak, Krishna Venkataraman, Ryan Murphy, and Manpreet Singh, Packt Publishing, here: https://www.packtpub.com/big-data-and-business-intelligence/stream-analytics-microsoft-azure.