# uTP testing infrastructure

Testing infrastructure which enables to test uTP implementation over different
network conditions on a local machine.

Uses following tools developed to test the QUIC protocol:

[quic-interop-runner](https://github.com/marten-seemann/quic-interop-runner)

[quic-network-simulator](https://github.com/marten-seemann/quic-network-simulator)

## Prerequisities

- Machine with Docker installed

- nimbus-eth1 set-up to run `make utp_test`

## How it works

Test setup uses Docker Compose to start 3 Docker containers:
- uTP client - which is an instance of the `utp_test_app`
- uTP server - which is an instance of the `utp_test_app`
- sim - which is an instance of the ns3 network simulator with several pre-compiled scenarios

The networking is set up in such way that network traffic is routed from client to server
and server to client through the simulator.
The simulator decides what to do with packets passing through based on the selected scneario.

Explanation from [quic-network-simulator](https://github.com/marten-seemann/quic-network-simulator):

```
The framework uses two networks on the host machine: `leftnet` (IPv4
193.167.0.0/24, IPv6 fd00:cafe:cafe:0::/64) and `rightnet` (IPv4
193.167.100.0/24, IPv6 fd00:cafe:cafe:100::/64). `leftnet` is connected to the
client docker image, and `rightnet` is connected to the server. The ns-3
simulation sits in the middle and forwards packets between `leftnet` and
`rightnet`
```

## Practicalities

For now the process is semi-manual (TODO automate this as much as possible)

To run integration testing scenarios with different network conditions:

```
1. cd nimbus-eth1/
2. docker build -t test-utp --build-arg BRANCH_NAME={branch-name} fluffy/tools/utp_testing/docker
3. SCENARIO="scenario_details" docker-compose -f fluffy/tools/utp_testing/docker/docker-compose.yml up

For example:
SCENARIO="drop-rate --delay=15ms --bandwidth=10Mbps --queue=25 --rate_to_client=0 --rate_to_server=0" docker-compose -f fluffy/tools/utp_testing/docker/docker-compose.yml up
would start `drop-rate` scenario with specified delay, bandwith, and different drop rates
4. make utp-test
```

All scenarios are specified in: [scenarios](https://github.com/marten-seemann/quic-network-simulator/tree/master/sim/scenarios)