Midn Core

Experimental LTE/5G Core Network — Rust

An experimental, from-scratch implementation of a 3GPP mobile core network. Not production-ready. Not feature-complete. Built to understand what a data-oriented, zero-copy cellular core actually looks like when you stop accepting the assumptions of legacy stacks.

What it is

A private LTE/5G core network with:

• Milenage/TUAK — 3GPP AKA authentication against real SIM cards
• NAS / S1AP / NGAP — control plane protocol parsers and state machines
• MME / AMF — subscriber session lifecycle backed by an ECS registry
• GTP-U — zero-copy user plane tunnel parser
• eBPF / XDP — kernel-level packet steering (Phase 3)

What it is not

• Production-ready (Phase 1 in progress)
• A full 3GPP compliance suite
• A drop-in replacement for OpenAirInterface or free5GC
• Stable API (everything changes until v1.0)

Crates

Crate	Role	Phase
midn-auth	Milenage / TUAK SIM authentication	1 — active
midn-proto	NAS, S1AP, NGAP, GTP-U	2
midn-core	MME/AMF state machine + ECS subscriber registry	2
midn-userplane	UPF routing + eBPF loader (Linux)	3
midn-userplane-ebpf	Kernel XDP program — no_std	3

Quick Start

# Phase 1: authentication only
cargo build -p midn-auth
cargo test  -p midn-auth

# Phase 2: protocol stack
cargo build -p midn-proto
cargo test  -p midn-proto
cargo build -p midn-core
cargo test  -p midn-core

# Benchmarks (release numbers only — debug is meaningless for perf)
cargo bench -p midn-auth
cargo bench -p midn-proto

mid-math dependency

Signal geometry and handover calculations use mid-math. Pick one option in the root Cargo.toml and uncomment it:

# Git (CI-friendly)
# mid-math = { git = "https://github.com/Mid-D-Man/mid-engine", branch = "main" }

# Local path (mid-engine checked out alongside midn-core)
# mid-math = { path = "../mid-engine/crates/mid-math" }

Performance Targets

Subsystem	Target	Measured by
Milenage auth vector	< 10 µs	cargo bench -p midn-auth
GTP-U header parse	< 500 ns	cargo bench -p midn-proto
ECS subscriber spawn	< 1 µs	unit tests
Concurrent sessions	100k+	stress tests
XDP packet decision	< 200 ns (Phase 3)	kernel perf counters

CI

Tests and benchmarks run on GitHub Actions.

Trigger	What runs
Commit with --midn-auth	midn-auth tests
Commit with --midn-proto	midn-proto tests
Commit with --midn-core	midn-core tests
Commit with --midn-all	all crates
Actions tab (manual)	always runs all

Benchmark workflow is manual-only (Actions → "midn-core: Benchmarks").

eBPF (Phase 3, Linux ≥ 5.8 only)

rustup toolchain install nightly --component rust-src
cargo install bpf-linker

cargo +nightly build -p midn-userplane-ebpf \
  --release --target bpfel-unknown-none -Z build-std=core

License

MIT