Bit Twister

Bit Twister: A CLI tool for precise network traffic shaping. Simulate latency, bandwith limitation, drop packets, impose jitter with ease. Enhance your network testing capabilities for development.

Build

make all

Usage

sudo ./bin/bittwister start [flags]

Flags:
  -b, --bandwidth int                bandwidth limit in bps (e.g. 1000 for 1Kbps)
  -h, --help                         help for start
  -j, --jitter int                   jitter in milliseconds (e.g. 10 for 10ms)
  -l, --latency int                  latency in milliseconds (e.g. 100 for 100ms)
      --log-level string             log level (e.g. debug, info, warn, error, dpanic, panic, fatal) (default "info")
  -d, --network-device-name string   network interface name
  -p, --packet-loss-rate int32       packet loss rate (e.g. 10 for 10% packet loss)
      --production-mode              production mode (e.g. disable debug logs)
      --tc-path string               path to tc binary (default "tc")

Example

# Apply 25 percent packet loss to eth0
sudo ./bin/bittwister start -d eth0 -p 25

# Apply 1 Mbps bandwidth limit to eth0
sudo ./bin/bittwister start -d eth0 -b 1048576

# Apply 100 ms latency to eth0
sudo ./bin/bittwister start -d eth0 -l 100

# Apply 10 ms jitter to eth0
sudo ./bin/bittwister start -d eth0 -j 10

Start the API server

sudo ./bin/bittwister serve [flags]

Flags:
  -h, --help                    help for serve
      --log-level string        log level (e.g. debug, info, warn, error, dpanic, panic, fatal) (default "info")
      --origin-allowed string   origin allowed for CORS (default "*")
      --production-mode         production mode (e.g. disable debug logs)
      --serve-addr string       address to serve on (default "localhost:9007")

API Endpoints

Please note that all the endpoints have to be prefixed with /api/v1.

Packet Loss

• Endpoint: /packetloss
  • /start
    • Method: POST
    • Data: {"network_interface":"eth0","packet_loss_rate":30}
    • Description: Start packetloss service.
  • /status
    • Method: GET
    • Description: Get packetloss status.
  • /stop
    • Method: POST
    • Description: Stop packetloss service.

example:

curl -iX POST http://localhost:9007/api/v1/packetloss/start --data '{"network_interface":"eth0","packet_loss_rate":30}'

Bandwidth

• Endpoint: /bandwidth
  • /start
    • Method: POST
    • Data: {"network_interface":"eth0","bandwidth":1048576}
    • Description: Start bandwidth service.
  • /status
    • Method: GET
    • Description: Get bandwidth status.
  • /stop
    • Method: POST
    • Description: Stop bandwidth service.

Latency

• Endpoint: /latency
  • /start
    • Method: POST
    • Data: {"network_interface":"eth0","latency":100,"jitter":10}
    • Description: Start latency service.
  • /status
    • Method: GET
    • Description: Get latency status.
  • /stop
    • Method: POST
    • Description: Stop latency service.

Services

• Endpoint: /services
  • /status
    • Method: GET
    • Description: Get all network restriction services statuses and their configured parameters.

SDK for Go

The BitTwister SDK for Go provides a convenient interface to interact with the BitTwister tool, which applies network restrictions on a network interface, including bandwidth limitation, packet loss, latency, and jitter. More details about the SDK and how to use it can be found here.

Using Bittwister in Kubernetes

To utilize Bittwister within a Kubernetes environment, specific configurations must be added to the container.

For simulating latency and jitter, the container needs to be granted additional capabilities. This can be achieved by adding the NET_ADMIN capability to the container's security context:

securityContext:
  capabilities:
    add:
      - NET_ADMIN

For simulating packet loss and limiting bandwidth, the container needs to operate in privileged mode. This can be set in the container's security context as follows:

securityContext:
  privileged: true

Test

The tests require docker to be installed. To run all the tests, execute the following command:

make test

Go unit tests

The Go unit tests can be run by executing the following command:

make test-go

Note: Root permission is required to run the unit tests. The tests are run on the loopback interface.

Test Packet Loss

The packet loss function can be tested by running the following command:

make test-packetloss

Results:
Number of packets per test: 50

Packet loss: 0%     Expected: 0%
Packet loss: 6%     Expected: 10%
Packet loss: 28%    Expected: 20%
Packet loss: 48%    Expected: 50%
Packet loss: 68%    Expected: 70%
Packet loss: 78%    Expected: 80%
Packet loss: +25    Expected: 100%

Test Bandwidth Limitation

The bandwidth limitation function can be tested by running the following command:

make test-bandwidth

Results:
Number of parallel connections per test: 128
Test duration per test: 600 seconds
expected bandwidth: 64 Kbps      actual bandwidth: 47 Kbps
expected bandwidth: 128 Kbps     actual bandwidth: 92 Kbps
expected bandwidth: 256 Kbps     actual bandwidth: 186 Kbps
expected bandwidth: 512 Kbps     actual bandwidth: 361 Kbps
expected bandwidth: 1024 Kbps    actual bandwidth: 0 bps
expected bandwidth: 2 Mbps       actual bandwidth: 1 Mbps
expected bandwidth: 4 Mbps       actual bandwidth: 2 Mbps
expected bandwidth: 8 Mbps       actual bandwidth: 6 Mbps
expected bandwidth: 16 Mbps      actual bandwidth: 13 Mbps
expected bandwidth: 32 Mbps      actual bandwidth: 24 Mbps
expected bandwidth: 64 Mbps      actual bandwidth: 49 Mbps
expected bandwidth: 128 Mbps     actual bandwidth: 100 Mbps
expected bandwidth: 256 Mbps     actual bandwidth: 187 Mbps
expected bandwidth: 512 Mbps     actual bandwidth: 459 Mbps
expected bandwidth: 1024 Mbps    actual bandwidth: 948 Mbps

Test Latency

The latency function can be tested by running the following command:

make test-latency

Results:
Number of packets per test: 10

Average latency: 11.203 ms       Expected: 10 ms
Average latency: 55.192 ms       Expected: 50 ms
Average latency: 110.250 ms      Expected: 100 ms
Average latency: 220.238 ms      Expected: 200 ms
Average latency: 550.342 ms      Expected: 500 ms
Average latency: 770.362 ms      Expected: 700 ms
Average latency: 1100.419 ms     Expected: 1000 ms
Average latency: 1700.255 ms     Expected: 1500 ms
Average latency: 2300.317 ms     Expected: 2000 ms
Average latency: 3600.249 ms     Expected: 3000 ms
Average latency: 5166.803 ms     Expected: 5000 ms

Test Jitter

The jitter function can be tested by running the following command:

make test-jitter

Number of packets per test: 50

Average jitter: 4.199 ms       Max expected jitter: 10 ms
Average jitter: 16.465 ms      Max expected jitter: 50 ms
Average jitter: 34.757 ms      Max expected jitter: 100 ms
Average jitter: 66.711 ms      Max expected jitter: 200 ms
Average jitter: 167.649 ms     Max expected jitter: 500 ms
Average jitter: 216.576 ms     Max expected jitter: 700 ms
Average jitter: 289.205 ms     Max expected jitter: 1000 ms
Average jitter: 466.368 ms     Max expected jitter: 1500 ms
Average jitter: 660.321 ms     Max expected jitter: 2000 ms
Average jitter: 669.862 ms     Max expected jitter: 3000 ms
Average jitter: 780.299 ms     Max expected jitter: 5000 ms