Payload in Raw Scenario 

You can define the application-layer content in the payload configuration panel by expanding the test scenario tree and click either the Download or Upload depending on your traffic direction mode.

Payload Pattern defines how the payload content looks, and it provides four modes: Increment, Random, LongRandom, and Custom.

Length Type defines the length of the application-layer payload. The Infinite means that the application- layer content is large enough so that there will always be payload from the application layer during the test. The Finite means that the application layer has limited content to send to the lower layer, and you can define the length in the Patter Length field.The example below will limit the application- layer content to 10000 random bytes. As soon as these 10000 bytes are transmitted by the lower layer, the application layer will stop generating traffic.