User Manual

TRex 39 / 113
4.11.2 How to determine the packet per second(PPS) and Bit per second (BPS)
• Let’s look at an example of one flow with 4 packets.
• Green circles represent the first packet of each flow.
• The client ip pool starts from 16.0.0.1, and the distribution is seq.
TotalPPS =
∑
n
k=0
(CPS
k
× f low_pkts
k
)
Concurrent f low =
∑
n
k=0
CPS
k
× f low_duration
k
The above formulas can be used to calculate the PPS. The TRex throughput depends on the PPS calculated above and the value
of m (a multiplier given as command line argument -m).
The m value is a multiplier of total pcap files CPS. CPS of pcap file is configured on yaml file.
Let’s take a simple example as below.
cap_info :
- name: avl/first.pcap < -- has 2 packets
cps : 102.0
ipg : 10000
rtt : 10000
w : 1
- name: avl/second.pcap < -- has 20 packets
cps : 50.0
ipg : 10000
rtt : 10000
w : 1
The throughput is: m*(CPS_1*flow_pkts+CPS_2*flow_pkts)
So if the m is set as 1, the total PPS is : 102*2+50*20 = 1204 PPS.
The BPS depends on the packet size. You can refer to your packet size and get the BPS = PPS*Packet_size.
4.11.3 Per template allocation + future plans
• 1) per-template generator
Multiple generators can be defined and assigned to different pcap file templates.
The YAML configuration is something like this: