solana-labs / solana-voib-demo

Voice over Internet & Blockchain (VoIB) demo

Solana VoIB Demo

Introduction

Demonstration of the tokenization business model to implement Voice over Internet & Blockchain (VoIB).

Video Streaming Demo

Video streaming devices (currently Raspberry Pis) implement thin clients. They communicate with a gatekeeper application on a network gateway, which will open a connection upon request from a device. The data is not part of the transaction to Solana, so the data itself is not stored on chain. Devices pay for data before opening a connection by funding an account controlled by the bandwidth-prepay program. The gatekeeper can send instructions to the program either spending the account funds as data is sent, or refunding any remaining balance once the connection is closed. The client-tester and tcp-echo-server modules can interact with the gatekeeper code to test data transmission locally, not requiring any extra hardware.

The video demo right now is designed to run on a Raspberry Pi connected to an official Raspberry Pi Foundation camera v2, and an official Raspberry Pi Foundation touchscreen.

Installing

To build the UI, you need to install gtk. Instructions here.

Installing ffmpeg and mpv

ffmpeg and mpv need to be installed on the Pis for the video demo. We run with versions built on the Pis by this script, but have had varying success with the script. We have had to resort to copying successful builds onto unsuccessful machines. Versions of ffmpeg and mpv installed by other methods such as apt-get will likely work, but may have higher latency and/or CPU usage.

Cross compiling for the Raspberry Pi

While it is possible to build the project on a Raspberry Pi directly using Cargo, it will take a very long time (Initial build >30 min on a Pi 3 B+). Instead, you can easily build a cross compiler with Docker, then use scp or some other method to transfer the binaries to the Pis.

To start, install Docker and ensure that it is running in the background.

Next, navigate to the docker-xc directory and run (This will take a while)

$ docker build -t rust-pi-xc .

This builds a new docker image called rust-pi-xc that is ready to cross compile any rust project to Cargo's armv7-unknown-linux-gnueabihf target.

Now, any time you want to cross compile the stream-video package, go to the stream-video directory and run

$ docker run -v </absolute/path/to/repo/root>:/mnt -v </absolute/path/to/$HOME/.cargo/registry>:/root/.cargo/registry rust-pi-xc /mnt/stream-video/rpxc.sh

This runs rpxc.sh in the Docker container. The script tells the instance of Cargo in the container to cross compile the stream-video project. The script needs to be adapted to build other projects. docker run's -v options link directories in the host system to directories in the container, so that the build files persist. Once the compile is done, the binaries can be found in target/armv7-unknown-linux-gnueabihf/debug/. The rest of this guide assumes that you have copied the compiled binaries to the target/xc/ directory in the project directory on the Pis.

Setting up the video demo

Deploying the bandwidth prepay program

This repository depends on a Solana cluster, currently synced to v0.18.0. On the machine that will run the solana cluster, navigate to solana-voib-demo root and clone solana with the command:

$ git clone --branch v0.18.0 https://github.com/solana-labs/solana.git

Then build solana:

$ cd solana && cargo build --all

Deploy the bandwidth-prepay program:

$ cd bandwidth-prepay-program
$ ./deploy.sh

Setting up keypairs

The initiator, the gatekeeper, and the provider all need keypairs for the demo. The initiator can be an instance of client-tester for a local demo, or it can be an instance of stream-video running on a Pi for a video demo.

To setup the device's pubkey, navigate to either the client-tester directory locally, or the stream-video directory on a Pi and run

$ ./setup.sh

This puts the device's id.json into the config-local direcory.

To setup the gatekeeper's pubkey, navigate to the gatekeeper directory and run

$ ./setup.sh gatekeeper

This puts the gatekeeper's id.json and pubkey.json into the config-local directory.

To setup the provider's pubkey, run

$ ./setup.sh provider

This puts the provider's id.json and pubkey.json in gatekeeper/config-local/

Both the gatekeeper-pubkey.json and provider-pubkey.json files need to be copied to the client-tester's or the stream-video's config-local directory.

Running the video demo

The video demo runs in five parts (and should be started in this order):

1. The solana cluster
2. The provider drone
3. The gatekeeper program
4. The video listener
5. The video connecter

The video receiver and sender should run on separate Pis. The gatekeeper and cluster can be run on the same computer, or separate ones. A complete local demo, sending zeros instead of video data, can be run by replacing the video receiver with tcp-echo-server, and replacing the video sender with client-tester.

Starting the Solana cluster

See the Solana Book for instructions on how to start a testnet from the solana repo. You can use either a single-node or multi-node testnet.

Starting the provider drone

The provider drone distributes lamports from the provider's account to clients upon request.

In a new shell, navigate to the provider-drone directory and run

$ cargo run -- -k ../gatekeeper/config-local/provider-id.json

For useful messages from the drone, run with the environment variable

RUST_LOG=provider_drone=info,solana_drone::drone=info

Starting the gatekeeper program

In a new shell, navigate to the gatekeeper directory and run

$ cargo run --bin gatekeeper -- -k config-local/gatekeeper-id.json

This will listen on the default port of 8122.

You can get a complete set of command line options by running

$ cargo run --bin gatekeeper -- -h

If you would like account balance change notifications and other debug messages, run with the environment variable

RUST_LOG=gatekeeper,gatekeeper::contract=info

Starting the video listener

Running the GUI

The GUI operates bi-directionally, so it can act as either the video listener, or the video connecter, and can switch while running. A connection can be started from the GUI by pressing one of the call buttons at the top of the screen. To start it, begin by navigating to the stream-video directory. Then, ensure that the settings in config-local/config.toml are correct for your setup. If you do not have a config-local/config.toml, use template-config.toml as a template in creating one. Finally, run the GUI in one of the following ways:

1. Running the cross-compiled version

$ DISPLAY=:0.0 ../target/xc/stream_gui

2. Running a locally compiled version

$ DISPLAY=:0.0 cargo run --bin stream_gui

To get helpful debug messages, run with

RUST_LOG=stream_gui,stream_video::stream_video=debug

Running the CLI

On the Pi, navigate to the stream-video directory and run one of the following:

1. Running the cross-compiled version

$ ../target/xc/stream_cli listen

2. Running a locally compiled version

$ cargo run --bin stream_cli -- listen

To get helpful debug messages, run with

RUST_LOG=stream_cli,stream_video::stream_video=debug

Local demo

The local demo replacement is to run cargo run -- -p <PORT> from the tcp-echo-server directory. <PORT> specifies the listening port.

Starting the video connecter

Running the GUI

See "Running the GUI" in "Starting the video listener"

Running the CLI

On the Pi, navigate to the stream-video directory and run one of the following:

1. Running the cross-compiled version

$ ../target/xc/stream_cli connect -g </path/to/gatekeeper-pubkey.json> -v </path/to/provider-pubkey.json> -k </path/to/id.json> -G <GATEKEEPER_ADDRESS:PORT> -f <FULLNODE_ADDRESS> -l <NUMBER> -d <DESTINATION_ADDRESS:PORT>

2. Running a locally compiled version

$ cargo run --bin stream_cli -- connect -g </path/to/gatekeeper-pubkey.json> -v </path/to/provider-pubkey.json> -k </path/to/id.json> -G <GATEKEEPER_ADDRESS:PORT> -f <FULLNODE_ADDRESS> -l <NUMBER> -d <DESTINATION_ADDRESS:PORT>

where <FULLNODE_ADDRESS> is the IP address of a node in the solana cluster, <NUMBER> is the number of tokens to prepay into the contract, and <DESTINATION_ADDRESS:PORT> is the address and port of the video listener.

You can get a complete set of command line options by running

$ cargo run --bin stream_cli -- connect -h

To get helpful debug messages, run with

RUST_LOG=stream_cli,stream_video::stream_video=debug

Local demo

The local demo replacement is to run the client-tester. The arguments are the same, with the addition of the optional arguments -n <NUMBER> to specify the number of packets to send before closing the connection, and -s <SIZE> to specity the size in bytes of the packets. A complete set of its CLI options can be found by running cargo run -- -h from the client-tester directory.

Observing provider funds

You can optionally observe changes to the provider account's balance by navigating to the gatekeeper directory and running

$ cargo run --bin provider-account -- -f <FULLNODE ADDRESS> -p </path/to/provider-pubkey.json>

where <FULLNODE_ADDRESS> is the IP address of a node in the solana cluster.