PA PacketAlchemy
Learning Paths

Learning Paths

Ordered paths through the PacketAlchemy notes. Start at the top of a path and read down. Each step assumes the ones above it.

📶

Path 1 — EPC Foundations

The packet core from attach to charging. The foundation everything else builds on.

  1. LTE/lte-attach-flow.md — attach flow with failure points.
  2. LTE/lte-attach-procedure.md — attach procedure in detail.
  3. Protocols/diameter-s6a-mme-hss.md — S6a: MME and HSS.
  4. DNS/dns-in-epc.md — DNS in EPC, APN resolution.
  5. Protocols/gtp-c-deep-dive.md — GTP-C.
  6. Protocols/gtp-u-deep-dive.md — GTP-U.
  7. Charging/ocs-overview.md — OCS online charging.
  8. Roaming/gy-interface.md — Gy quota lifecycle and bearer fate.
  9. Charging/pcrf-gx-policy-control.md — PCRF / Gx policy.
  10. Protocols/pfcp-n4-sxa-control.md — PFCP (CUPS side: Sx).
  11. Troubleshooting/epc-end-to-end-playbook.md — put it together.
📡

Path 2 — 5G Core

From EPC to the service-based 5G Core: slicing, interworking, PFCP on N4, and converged charging.

  1. 5G/5g-core-evolution.md — from EPC to 5GC.
  2. 5G/network-slicing.md — slicing.
  3. 5G/epc-5gc-interworking.md — interworking.
  4. Protocols/pfcp-n4-sxa-control.md — PFCP on N4.
  5. Charging/chf-5g-charging.md — CHF converged charging.
  6. Diagrams/04-5g-core-architecture.md — architecture diagram.
  7. Diagrams/05-5g-pdu-session-flow.md — PDU session flow.
  8. Wireshark/full-5g-core-call-flow.md — full call flow.
  9. Wireshark/5g-advanced-pcap-analysis.md — advanced PCAP.
🔍

Path 3 — Troubleshooting & War Room

Packet analysis, hands-on scenarios, and outage simulations. For engineers who learn by breaking things.

  1. Protocols/packet-analysis-gtp-diameter.md — packet analysis.
  2. Lab/wireshark-core-analysis.md — Wireshark core analysis.
  3. Lab/deep-pcap-step-by-step-analysis.md — deep PCAP, step by step.
  4. Lab/scenario-attach-no-data.md — hands-on scenario: attach OK, no data.
  5. Troubleshooting/incident-simulation-no-internet.md — incident simulation.
  6. CaseStudies/real-epc-incidents.md — real incidents.
  7. WarRoom/global-core-outage-simulation.md — global outage.
  8. WarRoom/multi-domain-outage-simulation.md — multi-domain outage.
🌍

Path 4 — Roaming

Roaming fundamentals, steering, and roaming charging — where Gy meets the visited network.

  1. Roaming/lte-roaming.md — roaming fundamentals.
  2. Roaming/lte-roaming-steering.md — steering.
  3. Roaming/gy-interface.md — Gy and roaming charging.
  4. Protocols/diameter-s6a-mme-hss.md — S6a in roaming attach.
🎯

Path 5 — Interview Prep

Turn the foundations into answers: Q&A, an interview pack, real stories, and one outage talked through end to end.

  1. Finish Path 1 (EPC Foundations).
  2. Interview/core-network-interview-qa.md — Q&A.
  3. Interview/core-network-interview-pack.md — interview pack.
  4. CaseStudies/real-epc-incidents.md — have stories ready.
  5. WarRoom/global-core-outage-simulation.md — talk through an outage.

How to use the paths

New to packet core: Path 1, then Path 2.

Stuck on a live problem: Path 3, or jump to the note that matches your symptom via the notes index.

Preparing for an interview: Path 5.

Source notes live in the packetalchemy-telecom-notes repo on GitHub. Prefer deep dives? Start with the Blog or try the Attach OK, No Data lab.