from the NIC memory to the user space memory (Step 6). Then, the header and data
are sent to the client through the Ethernet NIC (Step 7). The additional overhead in
the local NIC read is the DMA transfer time compared to local cache read. Steps 8 and
9 are the same as steps 7 and 8 in Figure 5.1.
The communication mechanism of remote NIC read is very similar to the commu
nication steps of remote cache read in Figure 5.2, except that the requested file is read
from the NIC memory, not from the main memory in the service node (shown by the
dotted line (9) in Figure5.2).