Osmocom SIMtrace 2

Osmocom SIMtrace 2 is a software, firmware and hardware system for passively tracing SIM-ME communication between the SIM card and the mobile phone, and remote SIM operation.
While it was designed for SIM-ME communication, it supports all ISO 7816 smart-cards using the T=0 protocol (the most common case).

It is a followup of the SIMtrace project, providing more functionalities (e.g. remote SIM operation) and supporting multiple boards (e.g. SIMtrace with SAM3S, sysmoQMOD).


The SIMtrace 2 firmware supports several boards.
The firmware is written for an ATSAM3S4B micro-controller.

Note: The SAM3S is meanwhile labelled as not recommended for new designs by Atmel. However, there are plenty of hardware and software compatible upgrade options, including SAM4S. The upgrade is possible in the future.

SIMtrace v2

The main purpose of this board is to sniff the communication between a phone and a SIM card (or any card reader and smart-card).

This is the same circuit board as the previous SIMtrace v1, with the exception that the ATSAM3S4B micro-controller replaces the old AT91SAM7S64. Since the SAM3S is pin compatible with the SAM7S, any SIMtrace v1 board can be converted into a SIMtrace v2 board simply by replacing the micro-controller.

Note: This hardware is open source.


The SAM3S micro-controller with SIMtrace 2 firmware is also used on the sysmoQMOD board to provide remote SIM operation capabilities.

Note: This hardware is not open source.


The SIMtrace 2 firmware source code is available in git.
It is currently under active development and we recommend to flash the new firmware images to profit from the latest bug fixes and added functionalities.

The SIMtrace 2 firmware is a complete rewrite and can only be flashed on hardware with SAM3S ARM Cortex-M3-based micro-controllers.
The SIMtrace 2 firmware is not compatible with the older SIMtrace v1 using SAM7S ARM7TDMI-based micro-controllers.


The trace application firmware allow to sniff the communication between a phone and a SIM card (or any card reader and smart-card).
It is intended for the SIMtrace v2 hardware and its function is analog to the SIMtrace v1.

The sniffing is completely passive. It uses the RST, ATR, PPS (baud rate tested with F/D up to 512/32), and WT (waiting timeout) to properly parse the ISO 7816-3 TPDUs.
Currently only the T=0 protocol is supported since this is the most common protocol used (we haven't seen T=1 in use).

The application firmware to be flashed using DFU is simtrace-trace-dfu.bin.


To compile the firmware using the source code, or participate in the development, please refer to the instructions provided in the README .


The firmware images can be flashed as described here.

Host PC Software

The SIMtrace 2 host PC software are available in the simtrace2 git.


libosmocore and libusb.

to install both packages:

sudo apt-get install libusb-1.0-0-dev libosmocore-dev 

Compiling it

git clone git://
cd simtrace2/host/

Accessing it

Add udev rules so to be able to use SIMtrace 2 devices and access the device as non-root user:

# add current user to plugdev group (user needs to re-login for this change to take effect)
sudo adduser $USERNAME plugdev
# grant access permission to SIMtrace 2 for plugdev group
sudo wget --output-file=/etc/udev/rules.d/99-simtrace2.rules 
# reload udev rules
sudo udevadm control --reload-rules
sudo udevadm trigger



simtrace2-list allows to list all SIMtrace 2 compatible devices:

USB matches: 1
    1d50:60e3 Addr=4, Path=2-2.3, Cfg=1, Intf=0, Alt=0: 255/1/0 (SIMtrace Sniffer)

This is useful when you have multiple devices (such as with the Wiki) and have to specific with device to use by the other applications.


This will use the trace firmware and retrieve the sniffed phone-SIM communication.
The activity will be shown on the consol output:

simtrace2-sniff - Phone-SIM card communication sniffer 
(C) 2010-2017 by Harald Welte <>
(C) 2018 by Kevin Redon <>

Using USB device 1d50:60e3 Addr=4, Path=2-2.3, Cfg=1, Intf=0, Alt=0: 255/1/0 (SIMtrace Sniffer)
Entering main loop
Card state change: reset hold
Card state change: reset release
ATR: 3b 9f 96 80 1f c7 80 31 a0 73 be 21 13 67 43 20 07 18 00 00 01 a5 
PPS: ff 10 96 79 
PPS: ff 10 96 79 
Fi/Di switched to 512/32
TPDU: a0 a4 00 00 02 3f 00 9f 22 
TPDU: a0 a4 00 00 02 7f 20 9f 22 
TPDU: a0 a4 00 00 02 6f 46 9f 0f 
TPDU: a0 b0 00 00 11 81 43 43 43 20 45 76 65 6e 74 ff ff ff ff ff ff ff 90 00 
Card state change: reset hold

The TPDU will also be sent the GSMTAP frames to UDP/IPv4 localhost:4729.
This also allows to analyze the communication in wireshark using the GSM SIM dissector.

Add picture from clipboard (Maximum size: 48.8 MB)