Towards Memory Specialization: A Case for Long-Term and Short-Term RAM
arxiv.org
arxiv.org
All that being said, I'm really not qualified to speak in detail about the underlying implementation. Networking is not my background. Also, a lot of this stuff is probably changed since then. For example, Cisco IOS-XE and IOS-XR have gained prominence. Both of those are based on Linux and probably means lots of changes under the hood.