Talk

I presented my recent work on Firefox’s HTTP3/QUIC stack in the Network Devroom at FOSDEM 2025. QUIC is a new transport protocol on top of UDP, transporting a large portion of the Internet traffic today. UDP I/O performance is crucial for QUIC implementations, where e.g. system call overhead can significantly impact throughput at high network speeds. To improve QUIC throughput, Firefox is switching to a modern UDP IO stack in Rust, using mechanisms like recvmmsg, and GRO across Linux, Windows, and Android. ...

How you can connect everything (browsers & non-browsers), everywhere (public or private), all at once (using libp2p). Slides

I presented at IPFS Camp 2022 on mitigating Denial-of-Service attacks in peer-to-peer networks. I discussed resource management strategies such as enforcing backpressure and provided examples of coding pitfalls to avoid in Rust and Go. You can find the recording and slides of my talk below. Slides DOS Denial-of-service attack Hard in peer-to-peer as identities are cheap Relevant for any scarce resource, e.g. CPU, memory(, file descriptors) Do’s Bound EVERYTHING Once a bound is exceeded: Drop item (good) Enforce backpressure (good) Do’s Backpressure Slow consumer should slow down a fast producer Can improve resource utilization Can improve latency Don’ts // Decode the length prefix of a message. let l = uvi::decode::usize(msg_len_prefix)?; // Allocate a corresponding buffer. let buffer = vec![0; l]; // Read message into buffer. socket.read_exact(&mut buffer)?; Don’ts for { // Receive a request. request := <- incomingRequests // Handle the request. go handleRequest(request) } Don’ts loop { // Receive a request. let request = incoming_requests.next().await?; // Handle the request. spawn(async move { handle(request) }); } Don’ts loop { // Receive a request. let request = incoming_requests.next().await?; // Send the request somewhere else. request_channel.unbounded_send(request); } Don’ts // Buffer of requests let to_be_handled_later = Vec::new(); // ... let request = incoming_requests.next().await?; to_be_handled_later.push(request);

Dennis and I presented Hole punching in the wild, learnings from running libp2p hole punching in production, measured from vantage points across the globe in the network devroom at FOSDEM 2023. At FOSDEM 2022 I presented libp2p’s hole punching mechanism, overcoming NATs and firewalls with no dependencies on central infrastructure. One year has passed since. We rolled it out to live networks. We launched a large measurement campaign with many volunteers deploying vantage points in their home network, punching holes across the globe. ...

I presented an overview on Peer-to-peer Browser Connectivity options in the network devroom at FOSDEM 2023. Connecting from the browser to a public server with a valid TLS certificate is easy. But what if the server has a self-signed certificate? What if it isn’t public? What if it is another browser? This talk covers the intricacies of browser communication beyond the standard browser-to-server use-case. I will give an overview of the many protocols available and how they can be used in a peer-to-peer fashion without sacrificing authenticity, confidentiality or integrity. We will leverage the new WebTransport for secure communication to public servers with self-signed certificates and WebRTC for secure communication to other browsers, using hole puching, without the dependency on central infrastructure. ...

We’ll take a closer look at the recently added decentralized hole punching feature, allowing NAT and firewall traversal without the need for any central coordination servers (STUN and TURN). Recording

We will discuss the current state of the project, eyeball the various language implementations, take a look at the many live networks running on top of libp2p today and finally cover the project roadmap for the years to come. Recording

Gave a talk on hole punching in libp2p at FOSDEM 2022. Peer-to-peer hole punching without centralized infrastructure How libp2p can traverse NATs and firewalls without coordination through central STUN and TURN servers. libp2p is a universal, cross-platform, multi-language, modular peer-to-peer networking library powering multiple large-scale networks, for example IPFS. In the first part of the talk we’ll present the basic building blocks of the library and explain how they fit together. In the second part, we’ll take a closer look at the recently added decentralized hole punching feature, allowing NAT and firewall traversal without the need for any central coordination servers (STUN and TURN). ...

Gave a talk on the state of libp2p at FOSDEM 2022. State of libp2p Status quo and future roadmap of the peer-to-peer networking library libp2p. libp2p is a universal, cross-platform, multi-language, modular peer-to-peer networking library powering multiple large-scale networks, for example IPFS, Ethereum 2, Filecoin or Polkadot. We will discuss the current state of the project, eyeball the various language implementations, take a look at the many live networks running on top of libp2p today and finally cover the project roadmap for the years to come. ...

On Tuesday 20th of July I gave a talk introducing libp2p, a modular network stack. Recording Slides