TRN-01 · Transport and Edge
Read the kernel code, then write your own.
Understand how BBR models the network, read its implementation, and build and evaluate a congestion-control module of your own.
You build: a custom congestion-control module with a comparison study.
Prefer to be taught it live? I/O & Network Performance Tuning (PRF-220, 4 days) is the same material delivered in a scheduled cohort by an instructor, in person or online. See the live course · Live dates
Promise
Understand BBR's model, read its kernel code, and build and evaluate a custom congestion-control module.
Prerequisites
TCP; C; PDP-01 recommended.
Units
1. Congestion control and BBR ch 01–04
the overview, why BBR was made, its core ideas, the v1 algorithm.
2. Linux TCP and BBR code ch 05–08
kernel TCP and the three source-reading parts.
3. Later versions ch 09–10
BBR v2 and v3.
4. Build your own ch 11–17
environment, module framework, metrics, state machine, learning-based tuning, user–kernel communication, eBPF.
5. Evaluation ch 18–20
simulation and test environments, methods, BBR with QUIC.
6. Scenarios ch 21–24
data centers, WAN, mobile, satellite.
7. Production ch 25–28
security, deployment, monitoring, community and patches.
8. Capstone ch 29–30
an anti-jitter variant for live video.
Labs
Each lab names its environment and a pass check. Labs are not marked complete on "it ran" — the pass check has to hold.
| Lab | What you do | Environment |
|---|---|---|
| TRN-01ach 06 | Read the BBR code path for one sendPass check: Path written with function names | vm90 min |
| TRN-01bch 12 | Load a custom congestion-control modulePass check: Selected per socket | vm120 min |
| TRN-01cch 18 | Compare two algorithms on the same profilePass check: Chart and conclusion | sim90 min |
| TRN-01dch 24 | Satellite-profile evaluationPass check: Result reported | sim90 min |
Capstone project · CAP-10
Congestion-Control Experiment · 2 weeks
A video service stalls on mobile links.
Compare two congestion-control approaches on a defined profile with statistics. Recommend one, with its risks.
Deliverables: Scripts, data, chart, recommendation.
Outcomes
- I can explain BBR's bandwidth and round-trip model in my own words.
- I can load a custom congestion-control module and select it per socket.
- I can compare two algorithms on the same profile and report the difference.
Also in
How it runs
Work through the units in order. Each unit groups the chapters of the study guide with its share of the labs. You can start any time; there is no cohort date and nothing expires.
Labs run in a VM, a container, a simulator or on real hardware, and the card above names which. Where a lab needs hardware — an RDMA NIC, a programmable switch model, an FPGA — there is a simulator fallback so you are never blocked by equipment.
Questions
Do I get a certificate?
You get a completion record for the course. Path badges and project credentials are earned by passing the labs and the project review, not by attendance.
Can my team take this together?
Yes — and if you would rather have it delivered live, with the instructor in the room, this course also exists as a scheduled live cohort. See the live dates.
How long does it take?
≈ 30 h of study including the labs. Most engineers take it part-time over a few weeks.