Question and Answer

How Can I Generate Traffic Representative of "Realistic" Internet Traffic?

This is a common question from a number of our customers - they want to be able to test a router's performance under traffic conditions that, as closely as possible, mimic the traffic seen within the Internet.

Your first stop should be the National Laboratory for Applied Network Research (www.nlanr.net). In particular, check out the Internet statistics available at www.moat.nlanr.net/Datacube. Here, you'll find data captured from monitoring points throughout the Internet.

In February of this year, Agilent engineers performed an analysis on the data collected for the entire month at the Merit monitoring point. Through extensive analysis of this data, an accurate model for Internet traffic was developed.

Traditionally, an "Internet Mix" of packet lengths has been used, (7/12ths of the packets are 40 bytes in length, 4/12ths are 576 bytes in length, and 1/12ths of the packets are 1500 bytes in length). However, it was discovered that this is only an 89.2% correlation to actual packet length distributions.

A more accurate model, accurate to 98.5%, can be created with 4 traffic streams:

• 55% of packets are 40 bytes in length
• 15% of packets are 576 bytes in length
• 12% of packets are 1500 bytes in length
• 18% of packets are evenly distributed between 40 and 1500 bytes in length.

This can be modeled on RouterTester by creating a separate stream for each packet length or packet range. An even more accurate model can simulate the distribution of packet lengths in the Internet to 99.87% accuracy:

This model accurately reflects the spikes of packet lengths seen in the Internet, and also ensures that every packet length, from 28 octets through to 1500 octets, goes into the router.