Preparing telecom logs

Preparing telecom logs

Use this guide if you’re debugging a cellular modem, baseband, or radio stack: VoLTE/VoNR call setup, IMS registration, RRC connection issues, NAS attach failures, handover anomalies.

Accepted log types

logcat.ai ingests decoded text output from the major vendor diagnostic tools. Binary trace files in their native format (.qmdl, .dlf, .isf, .mcl, .hdf) are not accepted. Convert them to text first using the steps below.

Once converted, upload alongside the corresponding device-side logs:

  • Decoded modem text. QXDM/QCAT, MediaTek ELT, or Shannon DM exports (NAS, RRC, PHY, MAC layer messages).
  • Radio buffer logcat. adb logcat -b radio output.
  • Kernel dmesg. Modem subsystem driver events on the application processor side.

For the full accepted/rejected list, see Supported file types.

Converting vendor captures to text

Qualcomm: QXDM / QCAT

QXDM Professional captures .qmdl / .dlf / .isf binary trace files. Use QCAT to decode and export them as plaintext:

  1. Open the binary capture in QCAT.
  2. File → Save As, choose the .txt format (or Tools → Convert log to TXT depending on QCAT version).
  3. Upload the resulting .txt to logcat.ai .

MediaTek: MTKLogger and ELT

MTKLogger (DebugLoggerUI) captures binary mdlog traces, often as .mcl. Use the MediaTek ELT decode tool:

  1. Open the mdlog / .mcl capture in ELT.
  2. Export the decoded protocol layers as plaintext.
  3. Upload the resulting text file.

Samsung: Shannon DM

Samsung CP captures (.hdf, Sysdump output) are decoded with Shannon DM (or QXDM/QCAT depending on the chipset variant):

  1. Open the binary capture in Shannon DM.
  2. Export the decoded NAS/RRC/PHY/MAC messages as plaintext.
  3. Upload the text file.

What’s not accepted

These are rejected at ingest in their native form:

  • Qualcomm: .qmdl, .qmdl2, .dlf, .isf
  • MediaTek: .mcl, raw mdlog directories
  • Samsung: .hdf, raw Sysdump bundles

If you need to share a capture for which you don’t have a vendor-side decode tool, the trace is not analyzable by logcat.ai . The encoding is proprietary, and only the vendor’s tooling can produce a readable export.

Example questions to ask

Ask from the Research tab once the file is analyzed. Reach for Quick Search when you already know what you’re after, Deep Research when you need the root cause.

Quick Search for fast, cited lookups:

  • “Find all RRC connection rejects with cause.”
  • “Did the IMS registration succeed before the call?”
  • “Which bands did the modem camp on?”
  • “Show all call drops.”

Deep Research for multi-step root-cause investigations:

  • “Trace the attach failure through NAS messages.”
  • “Why did the VoLTE call drop at 14:32?”
  • “Correlate the modem reset with the kernel events on the AP side.”
  • “What caused the device to lose signal at 14:20?”

See Quick Search and Deep Research for how the two modes differ.

Next

  • Deep Research: multi-step protocol investigations across NAS, RRC, SIP, and AP-side logs.
  • Quick Search: fast lookups when you know the symptom.
  • Delta Comparison: compare a working capture against a failing one.