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TracketPacer
@tracketpacer.com

explainer thread re: some of the most important physical components & what actually does what in a(n ethernet) switch:

5 reposts49 likes

TracketPacer
@tracketpacer.com

ASIC: - looks at frames - decides where they go - very smart, very dry, does not touch wires PHY: - negotiates link speed - handles encoding / signaling - pushes electrons (or photons), meaning bits without the PHY, an ASIC is just thinking thoughts with nowhere to send em

TracketPacer
@tracketpacer.com

MII / GMII / SGMII / RGMII: - the private lil interface between the ASIC’s MAC & the PHY - sits inside the box, passing bits back & forth

TracketPacer
@tracketpacer.com

tl;dr ASIC = brain thinking PHY = mouth speaking (although it does have logic of its own in there too) MII variants = internal nervous system Ethernet is teamwork actually

TracketPacer
@tracketpacer.com

caveat for “well, actually”s—MII is not a physical chip u can see on the board. the variants of MII are basically interface standards for signaling/clock frequencies BUT sometimes u can open up a switch & see traces on the board between the ASIC & PHY. that’s where your MII logic is applied :)

Frederik Hansen
@handle.invalid

For anyone wondering ASIC is an acronym for (Application Specific Integrated Circuit) and can be used to talk about anything from ethernet switches to bitcoin miners. For "cheaper" or lower volume things they are often just a pre implemented FPGA