Alocal area network is used as follows. the user issues a system call to write a data packet to the network. the operating system then copies these data to a kernel buffer. then it copies these data to the network controller board. when all the bytes are safely inside the controller, they are sent over the network at a rate of 10 megabits/sec. the receiving network controller stores each bit a microsecond after it is sent. when the last bit arrives, the destination cpu is interrupted, and the kernel copies the newly arrived packet to a kernel buffer to inspect it. once it has figured out which user the packet is for, the kernel copies the data to the user space.

if we assume that each interrupt and its associated processing takes 1 millisecond (msec), that packets are 1024 bytes long (including the headers), and that copying a byte takes 1 microsecond (μsec), what is the maximum rate at which one process can pump data to another?

assume that the sender is blocked until the work is finished at the receiving side and an acknowledgement comes back. for simplicity, assume that the time to get the acknowledgement back is so small that it can be ignored. [suggestions: observe 1) how many times a packet is copied and how long it takes, 2) how many interrupts are there to be processed and how long that takes, and 3) how long the transmission of a packet takes. then calculate the overall data transmission rate.]