[ih] Overlay networks

[Barbara Denny]

In 1985 and 1986, SRI performed a few experiments at SAC of the Reconstitution Protocol. I think the term overlay network applies to what we did to repair partitioned networks.  The overlay network was dynamic in the sense if the network repaired itself,  the overlay network disappeared. These experiments used Packet Radio networks and the ARPAnet. 
If you haven't heard of these experiments before, they were a lot of fun.  I got to break ARPAnet links and we had military aircraft involved.
Excuse any typos/word modifications from my phone. Missed the big one in the last message.
barbara

    On Wednesday, August 20, 2025 at 01:53:46 PM PDT, Brian E Carpenter via Internet-history <internet-history at elists.isoc.org> wrote:  
 
 On 21-Aug-25 01:57, Joe Touch via Internet-history wrote:
...

> So overlays go back over 20yrs as an active area of investigation before the ones you found. Anyone know of earlier that explicitly layered a net on a working net? (Vs ones that arguably to this with different layers, as with bang-path routing of email in the 1980s)

As you say, the model is recursive. At CERN in the late 1980s we layered bridged Ethernet over CERNET (the in-house packet switching network) and layered TCP/IP, DECnet, and probably more on top of that. In the early 1980s, I personally layered a primitive version of OSI/CLNP directly over another rather obscure in-house packet switching network. This was just the obvious thing to do.

Regards/Ngā mihi
    Brian Carpenter