It’s hard to remember back to those days but there was a huge legal/congressional pushback against p2p technology driven by the big media companies who saw p2p as the core enabler of file sharing. One side effect was the legal risks of providing p2p services were looking way heavier than traditional client service services. Skype was also heavily used in those days by people who wanted “anonymity” not from the government but from other users on the web. The old p2p architecture allowed users to discover each other’s IP addresses and either attack or discover identities of the other person on the call. I won’t for a moment pretend to say I think Microsoft has made good decisions around Skype (the UI is an unmitigated disaster that somehow still manages to get worse with each new release), but I do believe there were a ton of reasons back in the era of their switch from p2p to client server architectures that did make it the legitimately correct engineering decision in that moment. That’s nowhere near as fun an answer as the NSA conspiracy theories, but engineering decisions don’t have to be fun.

I remember back then ISPs would just block p2p traffic outright every once in a while to see if they could get away with it.

One time I got a piracy warning (not dmca, just like an angry generalized letter) because I had p2p traffic... For torrenting Ubuntu lol

Does someone have a good writeup of this? Engineering wise they could still do peer to peer, but also send lower sampled audio to a central server via UDP, code it into text, then send it to the other client and brand it as an accessibility feature. Fast connection with NSA logs :)

A good talk on this subject is NSA Operation Orchestra: Annual Status Report[1].

1. https://youtu.be/fwcl17Q0bpk