From Oscilloscope to Wireshark: A UDP Story
5 hours ago
- #Network Analysis
- #UDP
- #QSGMII
- UDP is a transport-level protocol in the OSI model, used for sending messages through an IP network.
- The article details a deep dive into UDP packets, starting from raw voltage waveforms captured by an oscilloscope.
- The author works at Oxide Computer Company, focusing on the management network for rack-scale computers.
- The investigation involved decoding QSGMII (Quad Serial Gigabit Media-Independent Interface) signals to analyze UDP packets.
- QSGMII combines four SGMII streams into a single physical link, using 8b/10b encoding for data transmission.
- The process involved synchronizing with comma characters in the data stream to correctly interpret the code-groups.
- The decoded data was then converted into Ethernet frames and further analyzed using tools like Wireshark.
- The final output was a .pcap file containing the decoded UDP packets, confirming the successful analysis.
- The article highlights the challenges and solutions in low-level network debugging and packet analysis.