Serial multiplexing

I’ve ran into a dilemma with a project. I need to get several serial links between 2 locations, but only have access to 1 serial channel. I already have an arduino mega at each end. Does anyone know of a library or setup that can ‘tunnel’ a couple of low baud serial connection over a higher baud setup?

I thought I would ask before I started attacking it. I can see how it could be done, but can also see a lot of pitfalls, does anyone know of an existing library that can do this?

Boards [u]can[/u] handle more serial connections.. If you want to use a signle channel, you can tag each transmission packet with channel number and size. This way the receiving end can determine "what/where"

That was nominally my plan, its handling the buffering, routing etc that will cause me issues. I didn't want to half ass it, if someone had already done it properly.

I would use TP-cable and hook up two separate connections...

Sufficed to say adding another serial line is not an option. In its final setup it will be operating at long range via a fibre optic system. It's the existing fibre channel creating the limit (high speed but only 1 channel for 3 independent data streams.

OK. then there is the option of packets containg ID and size++

only 1 channel for 3 independent data streams

Are the three data streams at the same baud rate? Is it one way or two way communication?