Long description

A set of four blocks consisting of two segments labeled user space and kernel space is shown here.

Figure a: Here a modem is pointed to the user process inside the user-space given segment.

Figure b: Here a modem is pointed to the rectangular block of the user process given inside the user-space segment.

Figure c: Here an arrow labeled 1 is pointed from the modem to a block given inside the kernel space. Again an arrow labeled 2 is pointed from this block to another block of user process given inside the user space.

Figure d: Here two arrows labeled 1 and 3 are pointed from the modem to two blocks given inside the kernel space. Another arrow labeled 2 points from the first block to another block of user process given inside the user space.