5G Traffic Generator

A high-performance toolkit for generating 5G GTP-U traffic with fully formed headers, including TEID and QFI. Designed for testing 5G user plane functionality, telemetry, and network slicing experiments.

This toolkit emits wire-format GTP-U packets with TEID and QFI headers that can be observed in Wireshark, replayed over real networks, and used to test slice-aware telemetry, queue-level behavior, and congestion response in realistic 5G user plane scenarios.

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Features

• GTP-U headers with TEID and optional QFI extension
• AF_PACKET + multithreading for high performance (~1Mpps with 4-6 cores)
• CBR mode for constant bit rate traffic with varying TEIDs and QFIs
• Profile-driven mode for more realistic traffic based on PCAP traces
• Anomaly injection for triggering bursts, overloads, and queue stress per TEID/QFI
• Tools for encapsulation, replay, and analysis of PCAP traces

Build Instructions

sudo apt-get install libpcap-dev libjansson-dev
mkdir build && cd build
cmake ..
make

After building, run a simple test to confirm GTP-U packets are being generated correctly:

./scripts/gtpu_sender_test.sh

You should see output like:

Sent GTP-U packet 1 with TEID=0x100 and QFI=5
Sent GTP-U packet 2 with TEID=0x101 and QFI=6
Sent GTP-U packet 3 with TEID=0x102 and QFI=7
Sent GTP-U packet 4 with TEID=0x103 and QFI=8

You should be able to caputure these packets with Wireshark on the specified interface.

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Usage Options

1. CBR Traffic (Simple, Repeatable)

Use gtpu_cbr_generator to send constant bit rate GTP-U traffic with fixed TEIDs and QFIs.

sudo ./build/gtpu_cbr_generator --interface eth0 --pps 500000 ...

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2. Profile-Driven Traffic (Realistic)

Use traffic traces to model application behavior. This approach uses JSON configs to control per-TEID behavior.

Step-by-step:

1. Get traffic traces
   Use your own PCAPs or download datasets such as 5G Traffic Dataset. (See sample_pcaps/ for small examples.)

2. Extract stats
   Analyze the PCAPs with:

   ./build/pcap_analyzer trace.pcap

   Generates trace.pcap.stats.json

3. Generate configs
   Use:

   python3 scripts/generate_teid_config.py <pcap_stats_dir>

   Outputs:

   • profiles.json: packet size/gap histograms
   • teid_map.json: TEID ↔ QFI/app mapping

See config/ for examples.

4. Run profile-based sender

   sudo ./build/gtpu_traffic_generator config/profiles.json config/teid_map.json eth0 192.168.1.1 192.168.1.2

3. PCAP Encapsulation & Replay

Use real application traces to simulate 5G user plane traffic.

Step 1: Encapsulate a PCAP

Wrap any packet trace with GTP-U, IP/UDP, and Ethernet headers using:

./build/gtpu_encapsulator input.pcap output_gtpu.pcap --teid 0x2001 --qfi 1

This produces a GTP-U-wrapped pcap (output_gtpu.pcap) that is Wireshark-compatible and ready for replay.

Step 2: Replay

Send the encapsulated packets on the wire via:

sudo ./build/gtpu_replay output_gtpu.pcap eth0

Step 3: Parallel Replay

Use the helper script to replay all GTP-U PCAPs in a directory:

sudo python3 scripts/replay_all_gtpu_pcaps.py \
  --interface eth0 \
  --pcap-dir ./encapsulated \
  --replay-binary ./build/gtpu_replay \
  --max-workers 8

Each PCAP is replayed in a separate process, with optional staggering. Useful for load or slice simulation.

4. Anomaly Injection

Use gtpu_anomaly_injector to simulate short bursts tied to specific TEIDs or QFIs:

sudo ./build/gtpu_anomaly_injector \
  --interface eth0 \
  --src-ip 192.168.1.1 \
  --dst-ip 192.168.1.2 \
  --teids 0x2000,0x2001 \
  --qfis 1,2 \
  --pps 600000 \
  --duration 3 \
  --num-threads 2

This tool is useful for testing bursty conditions.

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Tools Overview

Tool	Description
gtpu_cbr_generator	Constant-rate traffic with fixed TEIDs and QFIs
gtpu_traffic_generator	Profile-driven sender with per-TEID app behavior
gtpu_encapsulator	Wraps existing PCAPs in GTP-U, IP/UDP, Ethernet headers
gtpu_replay	Replays encapsulated PCAPs over the network
pcap_analyzer	Extracts stats (packet size, PPS, gaps) from PCAPs
gtpu_sender_test	Minimal functional test for TEID/QFI generation
gtpu_anomaly_injector	Injects bursts or micro-anomalies for telemetry testing

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