Packets/sec is the rate the Redirector is processing data packets. One packet includes (hopefully) many bytes. We say hopefully ...

Packets/sec is the rate the Redirector is processing data packets.  One packet includes (hopefully) many bytes.  We say hopefully here because each packet has protocol overhead.  You can determine the efficiency of this path by dividing the Bytes/sec by this counter to determine the average number of bytes transferred/packet.  You can also divide this counter by Operations/sec to determine the average number of packets per operation, another measure of efficiency.