Calculators & code lookup
Practical tools for the exercises: look up cause and error codes, convert dB, estimate link budgets, check availability, count SMS segments, normalise phone numbers. Everything runs in your browser; nothing is sent anywhere.
1. Code lookup (verified tables)
Search by number (decimal or 0x hex) or by words. Tables come from the IANA registries and the Wireshark dissector value tables (see References, verification log): MAP operations and errors, EMM/ESM/5GMM causes, GTPv2 types and causes, SMPP statuses, Q.850 causes, SIP responses, Diameter result codes, well-known ports.
2. dB, dBm and power
3. Free-space path loss and simple link budget
Free-space loss is optimistic: real urban distances are far shorter (Module 20). The result shows the maximum allowed path loss (MAPL) and the free-space distance that would use it all.
4. Noise floor and Shannon capacity
5. Availability and downtime
6. Erlang B (blocking and channels needed)
7. SMS segment counter
GSM-7 uses a basic 128-character set (extension characters such as € { } [ ] ~ ^ \ | count twice). Any character outside it (for example most emoji or "č") switches the whole message to UCS-2 (70 / 67 per segment). Single segment: 160 GSM-7 or 70 UCS-2; concatenated: 153 or 67 per part.
8. Phone number normaliser (E.164 helper)
Level 1–2 only (syntax and plausible length). This is not full validation: use libphonenumber for patterns, and HLR lookup / OTP to check existence and ownership (Module 35). Data: libphonenumber metadata, 23 regions.
9. IMSI splitter
The MNC is 2 or 3 digits depending on the country plan. The built-in MCC list contains only the codes confirmed in this guide's research (216, 218, 219, 220, 222, 293, 297); check others in the ITU E.212 list.