Calculation of Ethernet packets per second in PPS performance test flow test

Ehternet Baotou Format:

Gap/12bytes+preamble/8bytes+des add/6bytes+sourceadd/6bytes+type/length/2bytes+ (802.1Q/4bytes) +CRC/4bytes= 42bytes

In the calculation of PPS must be calculated GAP+PREAMBLE+CRC total 24bytes. Let's analyse, gap is called frame Gap, which is located between each Ethernet frame being sent, length is 12bytes, the function is to distinguish 2 frames before and after. Preamble are typically sent before real data, often including information that is used for proper reception, such as channel encoding, scrambling code, packet length, and so on. Some will be a training sequence for synchronization, channel estimation, frequency offset correction, etc., length is 8bytes.

The bit rate and PPS are not included GAP+PREAMBLE+CRC when the Cisco router receives the message and checks the traffic with ' show Interface/showpolicy-map '. That is to say, after the router has finished processing the message is not to see these 3 parts, but the message transmission on the link is carried by these 3 parts. See example: Interface bandwidth is 1G, data packets are sent ippayload for 60bytes/1500bytes, with VLAN TAG.

If Ippayload is 60bytes:1000000000bits/8/(60bytes+gap/12bytes+preamble/8bytes+desadd/6bytes+sourceadd/6bytes+type/ length/2bytes+ (802.1q/4bytes) +crc/4bytes) = 1225490. You can send 1,225,490 packets per second.

If Ippayload is 1500bytes:1000000000bits/8/(1500bytes+gap/12bytes+preamble/8bytes+desadd/6bytes+sourceadd/6bytes+ type/length/2bytes+ (802.1q/4bytes) +crc/4bytes) = 81063. You can send 81,063 packets per second.