Categories
EPC EUTRAN LTE Mobile Networks

S1AP – Relative Capacity (87) on MME

Functionality of eNB MME selection based on Relative Capacity IE

Categories
EUTRAN LTE Mobile Networks

Viewing the SIB – The LTE System Information Block with SDRs

Using SDR hardware to view the LTE System Information Block’s contents.

Categories
EUTRAN LTE Mobile Networks RFCs & Standards Software

Diameter Droplets – Origin-State-Id AVP

What the Origin-State-Id AVP does and how it is used to track if a Diameter peer restarts.

Categories
EPC EUTRAN LTE Mobile Networks

BaiCells USIM PLMN Issues (MNC 314 / MCC 030 vs MNC 311 / MCC 98)

Why the BaiCells PLMN changes?

Categories
EPC EUTRAN LTE Mobile Networks RFCs & Standards

LTE UE Attach Procedures in Evolved Packet Core (EPC)

A look into the signalling messages between Network elements in an Evolved Packet Core exchanged during the Attach Procedure

Categories
EUTRAN LTE Mobile Networks RFCs & Standards Voice over IP

Diameter and SIP: Registration-Termination-Request / Answer

These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Registration-Termination Request / Answer allow a Diameter Client (S-CSCF) to indicate to the HSS (Diameter Server) that it is no longer serving that user and the registration has […]

Categories
EUTRAN LTE Mobile Networks

srsLTE Install for BladeRF & LimeSDR on Debian / Ubuntu

Note: I’m running version 19.12.0 which I installed from the repos due to issues with 20.4.0 (latest when I wrote this) and stability on LimeSDR. I wrote the other day about installing SRS LTE stack, But installing it is one thing, meeting all the requirements to use it with your SDR hardware turns out to […]

Categories
EPC EUTRAN GSM LTE Mobile Networks

Sending SMS in Open5GS LTE Networks using the SGs Interface and OsmoMSC with SMSoS

Sending SMS over LTE using OsmoMSC and OsmoHLR and the SGs interface for SMSoS

Categories
EPC EUTRAN GSM LTE Mobile Networks

OsmoMSC and Open5GS MME – SGs Interface for CSCF / InterRAT Handover

Looking into the SGi interface for Circuit Switched Fallback in LTE to use GSM/UMTS networks for Calls & SMS

Categories
EUTRAN LTE Mobile Networks

Working with LTE MAC traces in Wireshark

Using Wireshark to view and analyze MAC layer LTE traffic

Categories
EUTRAN LTE RF

Field Test on an iPhone

Accessing the Field Testing suite on an iOS Device

Categories
EPC EUTRAN LTE Mobile Networks

Multi Operator Core-Networks (MOCN) for RAN Sharing

Multi-tenancy on the RAN side of the network, allowing an eNB to broadcast multiple PLMN IDs (MCC/MNC) in the System Information Block (SIB).

Categories
EPC EUTRAN Kamailio LTE Mobile Networks RFCs & Standards Voice over IP

Things I wish I knew about setting up private VoLTE Networks

Lessons learned about setting up VoLTE / IMS Networks at small scale.

Categories
EUTRAN LTE Mobile Networks

BaiCells Neutrino eNB Setup

Configuring BaiCells Neutrino eNB

Categories
EPC EUTRAN LTE Security Voice over IP

VoLTE / IMS – P-CSCF Assignment

How the P-CSCF address is assigned to a UE in Protocol Configuration Options (PCO) during bearer establishment.

Categories
EUTRAN LTE Mobile Networks Software

SRS LTE – Software Defined LTE Stack with BladeRF x40

Using SRS LTE Stack with the BladeRF x40 Software Defined Radio (SDR)

Categories
EPC EUTRAN LTE Mobile Networks Python RFCs & Standards Software Voice over IP

PyHSS Update – IMS Cx Support!

An update to PyHSS to support IMS Authentication for VoLTE

Categories
EPC EUTRAN LTE RFCs & Standards Voice over IP

IMS / VoLTE IPsec on the Gm Interface

The exchange between a UE and P-CSCF to put SIP traffic into IPsec encapsulated payloads.

Categories
EPC EUTRAN LTE Security Voice over IP

Using Wireshark to peer inside IPsec ESP VoLTE data from the P-CSCF

Viewing the payload of an Encapsulated Security Payload in Wireshark.

Categories
EPC EUTRAN LTE Mobile Networks Security Software Voice over IP

VoLTE/IMS Debugging on Samsung Handsets using Sysdump & Samsung IMS Logger

Unlocking the built in IMS Debugging tool in Samsung’s Sysdump Utility