Re: If this wasn't meant as a deliberate backdoor...
Via the network controllers, which in the name of performance would likely have DMA access. This has the added advantage of being CPU-agnostic so should work with Intel, AMD, or whatever CPU is running the thing. It would also have the advantage of working with otherwise-open-source hardware since the technology behind high-speed low-latency networking is still patent-protected last I checked, making open-source network chips of any serious performance nigh-impossible to obtain.
Biting the hand that feeds IT
