So ALMA, being an array, is a bit of a different beast than single-dish telescopes like the one where I'm employed; they do indeed have an array of antennae and

So ALMA, being an array, is a bit of a different beast than single-dish telescopes like the one where I'm employed; they do indeed have an array of antennae and correlate all the collected data at a central correlator (at least, for normal observations). My institute has a single, much larger primary reflector (30 meter diameter) and does not require such a process during normal observation. However, during VLBI observations, which EHT is, the receiver is dumping data to four collector computers, which is what I was referring to as "nodes" generating ~16Gbps of data apiece. I wish I could shed some more light on the ins-and-outs of exactly how these observations work, but I just run the computers, man. :) What I can tell you is that in order to move data off of the collector machines, they typically use m5copy, which is a part of the JIVE project (they have a Github repo: https://github.com/jive-vlbi/jive5ab https://github.com/jive-vlbi/jive5ab). All communication between the control computer and the collectors happens within a private, physically-distinct network, but it's just standard commodity networking equipment between the control computer and the collectors. The folks in charge of the node's design are in the process of removing some of the bottlenecks to make electronic transfers more viable (the current spec doesn't even include a 10Gbps uplink!).