NDN Video Streaming on the ndn6 Network

The ndn6 network, my own global scale Named Data Networking network, came back earlier this year. I moved my NDNts video streaming app into the ndn6 network, to reduce dependency on the NDN testbed. How well is it performing?


In my last article "NDN video streaming over QUIC", I used Chrome browser's experimental QuicTransport feature to perform video streaming over Named Data Networking. The analysis revealed that QUIC transport was generally performing better than WebSockets in this application, according to metrics including video resolution and startup latency.

Web technologies are constantly evolving. QuicTransport was in Origin Trial status at the time, but it was discontinued as of Chrome 91. WebTransport was introduced in its place. The main difference is that, WebTransport uses HTTP/3 as the underlying network protocol, while QuicTransport uses QUIC datagrams.

Since HTTP/3 runs over QUIC, I expect no performance difference between the two. I promptly registered for the WebTransport Origin Trial, and updated my gateways and NDNts libraries to use the new API.

NDN Video Streaming over QUIC

NDN over WebSockets == TCP over TCP

Named Data Networking (NDN) was first ported to web browser environment in 2012. At that time, a browser-based JavaScript application can communicate with the Internet via either XMLHTTPRequest or WebSocket. Feeling that WebSocket is a better match for the NDN implementation at the time, I wrote the initial code for a CCNx WebSocket proxy.

Web applications would connect to this proxy over TCP, negotiate a WebSocket connection, and send NDN packets in WebSocket frames. The proxy then decapsulates these frames, and delivers the NDN packets to ccnd forwarder over TCP.

NDN-over-WebSockets survived multiple protocol changes over the years, and made its way into the NDN Forwarding Daemon (NFD). It worked fine for simple NDN web applications, such as status pages and text chat, and even file retrievals.

Recently, with the rise of video streaming on the NDN testbed, congestion control functionality starts to show up in NDN libraries. Then, a question popped into my mind: WebSockets run over TCP, and NDN congestion control algorithms are largely borrowed from TCP, would this cause any problems?

What is a "Face" in Named Data Networking?

Face is an overloaded term in Named Data Networking (NDN). Most developers have some feeling of what a face is, but often find it hard to explain. This article attempts to demystify the concept of face in NDN.

"Face" as Defined in Publications

The original NDN paper, Networking Named Content, introduces the term face in a footnote:

We use the term face rather than interface because packets are not only forwarded over hardware network interfaces but also exchanged directly with application processes within a machine.

NFD, the original NDN forwarder software, explains in the NFD Developer Guide:

The Reality of NDN Video Streaming

As of 2019, video accounts for over 60% of downstream traffic on the Internet. It is believed that video streaming could benefit from the in-network caching feature of Named Data Networking (NDN), which would reduce the total traffic volume and bring cost savings for Internet service providers and content publishers. Far Cry: Will CDNs Hear NDN's Call?, a paper published at ACM-ICN 2020 conference, is the latest attempt on NDN video streaming.

How iViSA Works

In Far Cry, the authors implemented iViSA, a browser-based video streaming application that runs on the global NDN testbed, and then performed some comparison study between this application and similar HTTP video streaming application deployed on commercial CDN services.

It's said that if you want reproducible science, the software needs to be open source. The authors released most of their source code, and we can get a peek into how iViSA actually works.

The backend server repository contains:

Self-Hosted NDNts Nightly Build

NDNts nightly build is a set of NPM-compatible tarballs compiled automatically from the development branch of NDNts, Named Data Networking (NDN) libraries for the modern web, distributed on https://ndnts-nightly.ndn.today website. Users can install NDNts nightly build following these instructions.

However, this website only stores the latest version of NDNts packages. This has been causing installation conflicts when NPM tries to look for previous versions. Moreover, as I have declared, I don't care much about backwards compatibility. With NPM, all published versions are stored indefinitely, so you can continue using an older version without being affected by breaking changes. On the other hand, once a new nightly build is uploaded, the previous version is overwritten and no longer available for downloads. You are then forced to cope with the breaking changes I introduce from time to time, possibly at higher frequency than you would like to.

Today, I'm introducing two methods for self-hosting NDNts nightly build. Both methods allow you to build a specific version of NDNts codebase from a checkout of the NDNts monorepo, and generate a set of tarballs that you can host locally on a server under your control. Afterwards, you can install NDNts packages from this server, without relying on my website and without being affected by my breaking changes.

Self-Hosted NDNts on an HTTP Server

The following steps allow you to create and host tarballs of one specific version of NDNts.

NDNts Demo at NDN Community Meeting 2020

NDN Community Meeting is an annual event that brings together a large community of researchers from academia, industry, and government, as well as users and other parties interested in the development of Named Data Networking (NDN) technology. Having no peer review process, it is a prime opportunity to showcase my personal projects to the community. I demo'ed my ndn-js home surveillance camera at NDNcomm 2018. This time, I decide to demo my flagship product, NDNts: NDN Libraries for the Modern Web.

The Demo Video

NDNts is a set of libraries with many different features, where do I start? I decide to select a subset of unique features that are not found in any other library:

  • The Endpoint API that enhances face by automatically handling repetitive tasks such as Interest retransmissions and packet signing/verification, so that app developers can focus on the application logic.
  • An implementation of trust schemas.
  • NDN Certificate Management protocol implementation, including a graphical user interface for the certificate authority component.

I also threw in two web applications:

Getting Started with NDNts Web Application using webpack

This article shows how to get started with NDNts, Named Data Networking (NDN) libraries for the modern web. In particular, it demonstrates how to write a consumer-only web application that connects to the NDN testbed, transmits a few Interests, and gets responses. This application uses JavaScript programming language and webpack module bundler.

Code samples in this article were last updated on 2021-09-20 to reflect latest changes.

Prepare the System

To use NDNts, you must have Node.js. As of this writing, NDNts works best with Node.js 16.x, and you should install that version. The easiest way to install Node.js is through Node Version Manager (nvm) or Node Version Manager (nvm) for Windows.

On Ubuntu 20.04, you can install nvm and Node.js with the following commands:

NDNts Nightly Build

NDNts nightly build is a set of NPM-compatible tarballs compiled automatically from the development branch of NDNts, Named Data Networking (NDN) libraries for the modern web. They are built by the Continuous Integration (CI) system and uploaded to the NDNts nightly build website: ndnts-nightly.ndn.today. Homepage of that website displays a list of URIs of available tarballs.

How to install NDNts nightly build

You can find available tarballs on NDNts nightly build website: ndnts-nightly.ndn.today.

To install a tarball as a local dependency within the current project, you can execute something like:

$ npm install https://ndnts-nightly.ndn.today/packet.tgz
+ @ndn/packet@0.0.20200822-nightly.a471902
added 5 packages from 3 contributors and audited 5 packages in 1.612s
found 0 vulnerabilities

Getting Started with NDNts in Node.js

This article shows how to get started with NDNts, Named Data Networking (NDN) libraries for the modern web. In particular, it demonstrates how to write a producer and a consumer application in Node.js using JavaScript programming language, and transmit a few Interest and Data packets via NFD forwarder on the local machine.

Code samples in this article were last updated on 2021-08-17 to reflect latest changes.

Prepare the System

This guide is written for Ubuntu 20.04 operating system. If you have a Windows PC, you can enable Windows Subsystem for Linux and install Ubuntu 20.04 from the Microsoft Store. If you have a Macbook or a Linux machine other than Ubuntu 20.04, you can install Vagrant, and create a virtual machine using bento/ubuntu-20.04 template. All steps below should be executed inside Ubuntu 20.04 environment.

To use NDNts, you must have Node.js. As of this writing, NDNts works best with Node.js 16.x, and you should install that version. The easiest way to install Node.js is through Node Version Manager (nvm). To install nvm and then install Node.js, type the following commands in Ubuntu 20.04 terminal:

Introducing NDNts, Named Data Networking libraries for the Modern Web

I'm creating a new Named Data Networking (NDN) client library, NDNts. The initial NPM release, v0.0.20191223-beta.1, was uploaded yesterday. This article explains why I'm doing this, and why you should consider using my library.


I've been developing Named Data Networking (NDN) for several years. Although my specialty is in the forwarding plane, I occasionally build NDN applications, such as a home surveillance camera. A common ingredient of every NDN application is some sort of client libraries, which provides APIs that allow the application to encode/decode NDN packets and communicate over NDN networks in accordance with the NDN protocol. One of these client libraries is the NDN Common Client Libraries (NDN-CCL), which provide a consistent API across several programming languages.

I adopted ndn-js, the JavaScript variant of NDN-CCL, in several projects, and was unhappy about it:

  • The API feels like Java, not JavaScript.
  • Callbacks everywhere, leading to callback hell.
  • The library inserts over 50 symbols to the browser's global scope, causing name conflicts.
  • All features are bundled into a single file that weighs over 500KB.
  • There's no unit testing for the most part, let alone continuous integration.