An example using two machines with two pairs of hardware midi ports each...
Machine A has two midi input ports named "DX-7 In" and "Polysix In" and two output ports named "DX-7 Out" and "Polysix Out"
Machine B has two midi input ports named "TR-909 In" and "K5000s In" and two output ports named "TR-909 Out" and "K5000s Out"
On Machine A, Copperlan adds two pairs of Virtual midi ports named "TR-909 In", "K5000s In", "TR-909 Out" and "K5000s Out". These are routed to the relevant hardware midi ports on Machine B.
Likewise, on Machine B, Copperlan adds two pairs of Virtual midi ports named "DX-7 In", "Polysix In", "DX-7 Out" and "Polysix Out". These are routed to the relevant hardware midi ports on Machine B.
For hardware-only Copperlan appliances, their ports would be automatically added as named virtual midi ports to all the PC's.
Tobias Erichsen, the Windows rtpMidi guy, has some apps which dynamically creates virtual midi cable at runtime on WinXP and up so I figure this should be technically feasible, at least in Windows.
This would be a really intuitive way of managing the Copperlan configuration.