.SH 9P Protocol Drivers .PP The file server described so far waits for 9P protocol messages to appear in its input queue. It processes each message and sends the reply back to the originator. There are groups of processes that perform protocol I/O on some network or device and the resulting messages are sent to the file system queue. .PP There are two sets of processes .CW ethi and .CW etho that perform Ethernet input and output on two different networks. These processes send Ethernet messages to/from two more processes .CW ilo and .CW ilt that do the IL reliable datagram protocol on top of IP packets. .PP The last process in Emelie, .CW con , reads the console and calls internal subroutines to executes commands typed. Since there is only one process, only one command can be executing at a time. See .I fs (8) for a description of the commands available at the console.