Answer

Ports, Ramp Up Time, Call Duration and Call Attempts Per Second (CAPS) are related to each other with the following expressions:

Ports = Call Duration * CAPS

Ramp Up Time = Ports / CAPS

It's easy to see that Ramp Up Time in these expressions equals Call Duration. It is true when desired CAPS during the Ramp Up stage is the same as CAPS during the Sustain Load stage .

Examples:

1000 Ports load test with target CAPS of 20 (call attempts per second)

1. What is my Ramp up time if I do not want to exceed 20 CAPS?

Ramp Up Time = 1000/20 = 50 seconds

2. What is the minimal Call Duration needed to reach 1000 ports?

Call Duration = 1000/20 = 50 seconds

3. What if I want to Ramp Up faster and get to 1000 ports in 10 seconds? What would be my CAPS during Ramp Up period?

CAPS = 1000/10 = 100 CAPS

4. What is my CAPS rate during the Sustain Load stage if my call duration is 100 seconds:

CAPS = 1000/100 = 10 CAPS

5. Can I reach 1000 Ports at 20 CAPS if my call duration is 20 seconds?

Ports = CAPS * Call Duration = 20 * 20 = 400 Ports

Answer: No. The max Ports at this setup is 400.