This question was in pursuit of resolving some early proof of concept testing within a Smart Grid utility network. It was investigating how to transport bi-directional serial traffic between two devices across a Cisco routed infrastructure.
ANSWERS ARE:
a) Serial > TCP Raw Streaming is one solution there is some write ups on but it doesn’t work for bi-directionally because of varying serial communication line state changes that must be managed – can even be end-device dependent.
b) ‘Generic BSTUN’ is what Cisco is recommending for this case. However, this is a Cisco proprietary protocol and as such, won’t solve all connectivity requirements within mixed-vendor network.
c) Purpose-built serial>TCP/IP translators or data-gateway solutions exist to otherwise solve this issue.