@Wolfmanjm I think, if the network is fast enough then gcode command could get dropped by smoothie because the print buffer is full. Tcp/ip does flow control for the receive window, but not for the higher level application (the print buffer). Anyhow, once I find some free time I will try to implement a network backend and will need the help of others to test it.
@Mathias_Dietz that is incorrect, I wrote the TCP/IP stuff in smoothie so I know it works, you could actually do a cat file.gcode | nc ipadderss 23 if you wanted. It is totally irrelevant how fast the network is, this is just how TCP/IP works. It s quite complex and I would highly recommend you read up on TCP/IP it is an extraordinarily well designed protocol. Especially the windowing features 
@Wolfmanjm no worries. I know tcp/ip well enough but was concerned if the application is handling it correct. e.g. if the application accepts a packet even if its own buffer is full, tcpip would not help.
Anyhow, since you did the coding I trust that you are the expert in this area