The HP4952A Protocol Analyzer actually looks a lot like an old computer, even if it was never meant for general-purpose use. The heart of the machine is a Zilog Z80 CPU, though, so it shares a lot ...

Multi Stream UDP/TCP Traffic Generator and Analyzer is a hardware-based Ethernet tester capable of generating multi-stream Ethernet traffic of varying packet length ...

A hardware device or server software that captures packets transmitted in a network for routine inspection and problem detection. Also called a "sniffer," "packet sniffer," "packet analyzer ...

Amprobe LAN-1 Cable Tester is designed to work with various data cables and connectors. This cable tester provides a quick go/no-go LED display of the wiring and ...

Still, the software looks nice and even has an SPI protocol analyzer. It is all open source, so if you want other protocols before the author gets to them, you could always do it yourself.