This file provides a brief overview of the tgen tests which are defined in this directory and used to test shadow network performance.

We currently have two types of tgen tests: "fixed duration: and "fixed size" tests. More information about the tgen config files can be found in the gen_conf.py scripts in the respective directories.

In the fixed duration tests, two hosts connect to each other and transfer as much as possible for a fixed duration. This is like a standard speed test.

Our tests vary parameters along two main axes:

• Client behavior: we configure the client to create a different number of streams in parallel to the server, and upload and download effectively infinitely sized files. As an example, the config file name client.10streams.graphml encodes that 10 parallel streams are used.

• Network: we configure networks of varying quality, from slower networks (less bandwidth) with higher latency, to faster networks (more bandwidth) with lower latency. As an example, the config file name 10mbit_200ms.yaml encodes that the bandwidth is set to 10 Mbit and the latency to 200 ms.

We run the speed test over all combinations of client and network. The verify.sh script that runs after each test checks that we are able to reach within a percent threshold of the expected transfer speed as configured in the network host bandwdith part of the shadow config file.

In the fixed size tests, two hosts connect to each other and perform a number of transfers of a fixed size.

Our tests vary parameters along two main axes:

• Client behavior: we configure the client to create a different number of streams in parallel to the server, differently sized bidirational transfers, and a different number of total tranfers. As an example, the config file name client.1stream_1b_1000x.graphml encodes that 1 parallel stream is used, each transfer is 1 byte, and we repeat 1000 times.
• Network: we configure networks of varying quality, from slower networks (less bandwidth) with higher latency, to faster networks (more bandwidth) with lower latency. The config file name is the same as described above in the fixed duration section.

Again, we run all combinations of clients and networks. Our choice of client parameters is such that we test both streams in parallel and streams in serial, both over different network types. The verify.sh script that runs after each test checks that we successfully completed all transfers.