Open source all the way down at APNIC 60

Aris Cahyadi Risdianto moderates the Open Source session at APNIC 60.

Open source software underpins most networks and the Internet as a whole.

The Open Source Technologies session at APNIC 60 explored four different applications of open source software to networking and network operations.

PURPLE: Dynamic control of CAKE

Presenter: Duncan Cameron, Victoria University of Wellington, PhD Candidate

Bufferbloat, or excessive queuing delay under load, is a noticeable quality of service degradation that occurs when latency-sensitive traffic experiences the effects of increased packet buffering delays in network devices. This phenomenon leads to increased latency and reduced network performance, particularly affecting real-time applications.

Active Queue Management solutions (FQ-CoDel, CAKE) keep latency low by flow-queuing and dropping packets from disruptive flows. This works fine if you have consistent link capacities, but less well when you have variable links, which are common in wireless networks. Compromise rates are set, resulting in lost bandwidth. As Duncan puts it, "you really can't trust the averages" when it comes to measuring latency.

Cake is a comprehensive queue management system, implemented as a queue discipline (qdisc) for the Linux kernel. PURPLE is an algorithm designed by the Wireless Networks Research Group (WiNe) at Victoria University, Wellington, to estimate 'useful capacity' and control bufferbloat in wireless networks through dynamic adjustment of CAKE's bandwidth parameter. The algorithm draws inspiration from the BLUE active queue management scheme, itself being an evolution of RED, adapting its congestion detection mechanisms for wireless capacity estimation.

PURPLE monitors queue state, and makes dynamic adjustments based on congestion signals. It can obtain those signals by polling for target radio queue metrics (PURPLE), or by using unidirectional latency measurements relative to a target latency (PURPLE-AIMD). This approach offers clear reductions in bufferbloat, and improvements in user experience over static network shaping rules.

Slides: PURPLE: Dynamic Control of CAKE (3 MB)

Open source AAA for IPOE & PPPOE

Presenter: Sukhbaatar Erdenee, Skytel, Manager

Sukhbaatar Erdenee had a challenge. He had to integrate a business support system (BSS) with a Broadband Network Gateway (BNG) router to provide broadband with authentication, authorization, and accounting (AAA) to end users on IPOE and PPPOE connections, and bill them correctly for it. The solution had to be reliable, and it had to be basically free. But how? Open source!

Sukhbaatar's solution combined FreeRADIUS for AAA, keepalived for high availability, and a Galera Maria database cluster to manage state. He developed a custom REST API written in NodeJS to enable communication between the components. Monitoring was handled with Loki for log collection, and Grafana provided visualization.

The open source networking ecosystem allowed the construction of a modular system, with each component being chosen because it was best for its role in this use case. Each component has quality documentation and an active community, making it easier to find examples and troubleshooting help. The NodeJS API to the BSS allowed straightforward integration between it, FreeRADIUS, and the billing system.

The resulting system allowed 125,000 customers to be migrated to a new system without any interruptions.

Slides: Open-Source AAA for IPOE and PPPOE Solution (3 MB)

NetConsole: Open source tool to configure multiple switches

Presenter: Thang Phan, Senior Network Engineer

Thang Phan began his presentation with a question: "Did you know that in Viet Nam we have 20-year-old switches running in production"?

Manual configuration of switches is time-consuming and error prone, with different vendors providing different user experiences for accomplishing the same task. NetConsole is an open source project that allows the simultaneous configuration of multiple switches using a modern, easy-to-navigate web interface.

Thang Pan developed this centralized solution for managing network devices (especially older hardware) with a focus on 'Level 1' network operations. It combines a REACT frontend with a FastTAPI backend and a PostgreSQL database.

React allows quick development of interfaces using common interface components. FastAPI allows rapid development of APIs using Python, which gives it easy access to libraries that handle interactions with switches like nornir (a Python network automation framework) and netmiko (a multi-vendor Python library to simplify CLI connections to network devices). Packaging it as a Docker application allows rapid deployment with minimal hardware requirements.

Taken together, open source allowed Thang Pan to 'scratch his own itch' by developing Netconsole.

Slides: NetConsole - Open source tool to configure multiple switches (1 MB)

Setting up a telecom-grade temporary conferencing network

Presenter: Tsung-Yi Yu, also known as SteveYi

Large conferences demand rock-solid, high-speed networks to keep talks streaming, demos running, and attendees connected. Conference networking remains a significant challenge for event organizers, as stability and high throughput are paramount. In fact, this talk was inspired by the very same network architecture that powered networking at past APNIC conferences!

How hard could it be? "You won't know the outcome unless you try", SteveYi says, "so don't give up before you start".

To set up a network that he hoped could deliver a rock-solid conference experience, SteveYi used NetBox to provide data sources for automation, BGP Tools Looking Glass to perform BGP route lookups, and RIPE Atlas to test the routing. WireGuard VPN connected all the network services together in an out-of-band management network. Akvorado and Grafana were used for monitoring and visualizations, and SteveYi wrote some custom Go code to export traffic statistics.

Many of these projects are enterprise or telco-grade; in other words, they've been used in production and contributed to by organizations running the most demanding networks in the world. All of that experience and expertise is encapsulated in the open source code, for everyone to take advantage of.

Slides: Setting Up a Telecom-Grade Temporary Conferencing Network(966 KB)

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