.. _gen_troubleshooting:

Troubleshooting
==================

Building with Debug Symbols
**************************************

First make sure srsRAN 4G has been downloaded, and you have created and navigated to the build folder:: 
  
  git clone https://github.com/srsran/srsran_4g.git
  cd srsRAN_4G
  mkdir build
  cd build
  
To build srsRAN 4G with debug symbols, the following steps can be taken. If srsRAN 4G has already been built, the original build folder should be cleared before proceeding.  
This can be done with the following command:: 

  rm -rf *
  make clean  

The following command can then be used to build srsRAN 4G with debug symbols enabled:: 

  cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ../
  make
  make test
  
The log file containing the debug info can be found in the ``srsran_backtrace.log`` file.

.. _wireshark:

Examining PCAPs with Wireshark
******************************

The srsRAN 4G applications support packet capture at the MAC and NAS layers of the network stack.

Packet capture files (pcaps) can be viewed using Wireshark (www.wireshark.org). pcaps are encoded in compact MAC-LTE and MAC-NR form. They can be found in the */tmp* folder where other logs are located. 
To view in wireshark, edit the preferences of the DLT_USER dissector. 

To decode MAC pcaps add an entry with the following:

	* DLT=149
	* Payload Protocol=udp
	
Further, enable the heuristic dissection in UDP under:
*Analyze > Enabled Protocols > MAC-LTE > mac_lte_udp* and *MAC-NR > mac_nr_udp*	

Using the same filename for mac_filename and mac_nr_filename writes both
MAC-LTE and MAC-NR to the same file allowing a better analysis.
	
To decode NAS pcaps add and entry with the following: 

	* DLT=148
	* Payload Protocol=nas-eps

For more information, see https://wiki.wireshark.org/MAC-LTE.

The srsEPC application supports packet capture (pcap) of S1AP messages between the MME and eNodeBs. Enable packet captures in *epc.conf* or on the command line, by setting the *pcap.enable* value to *true*.
To view in wireshark, edit the preferences of the DLT_USER dissector. 

To decode S1AP pcaps add an entry with:

	* DLT=150
	* Payload Protocol=s1ap