IMS / VoLTE LTE Mobile Networks Software

Testing Mobile Networks with Remote Test Phones

Using Android’s development features to allow remote control of a UE in the field for testing the cellular network.

CGrateS EPC IMS / VoLTE Mobile Networks Software VoIP

CGrates in Baby Steps – Part 1

Getting started with CGrateS to bill for calls in a Telecom environment.

EPC LTE Mobile Networks

Evolved Packet Core – Analysis Challenge

This post is one of a series of packet capture analysis challenges designed to test your ability to understand what is going on in a network from packet captures.Download the Packet Capture and see how many of the questions you can answer from the attached packet capture. The answers are at the bottom of this […]

5G SA IMS / VoLTE Kamailio LTE Mobile Networks VoIP

The Surprisingly Complicated World of SMS: Apple iPhone MT SMS

Quirks and gotchas of working with SMS on IMS on iPhones.

EUTRAN LTE Mobile Networks RF

Huawei Baseband Cheat Sheet

Quick reference guide for the types and capacities of Huawei BBU 3900 Series cards

EPC EUTRAN IMS / VoLTE LTE Mobile Networks

Lifecycle of a Dedicated Bearer – From Flow-Description AVP to Traffic Flow Templates

A look at how Dedicated Bearers get established for VoLTE.

5G SA EPC LTE Mobile Networks SDM

Backing up and Restoring Open5GS

How to backup and restore Open5Gs config between servers

EPC Mobile Networks SDM

Jaffa Cakes explain the nuances between Centralized vs Decentralized Online Charging in 3GPP Networks

A look at Centralized vs DeCentralized Online Charging with the aid of sugar.

EPC LTE Mobile Networks RFCs & Standards SDM VoIP

Basics of EPC/LTE Online Charging (OCS)

A glimpse into the complexities of prepaid billing (Online Charging) Diameter based networks.

5G SA EPC Linux LTE Mobile Networks

Open5GS without NAT

Setting up Open5Gs without a NAT requirement, and the routing required to do so.

EPC LTE Mobile Networks RFCs & Standards SDM

Diameter – Insert Subscriber Data Request / Response

A look at how the HSS can update the profile of an already in-use subscription using Insert Subscriber Data Request/Response.

EPC LTE Mobile Networks SDM SIM Cards

PS Data Off

How turning mobile data off, doesn’t, in LTE and 5G.

EPC Mobile Networks RFCs & Standards VoIP

Docker & BIND as an ENUM Playground

A Bind environment in a Docker container for experimenting and learning ENUM for DNS based Call Routing.

GSM LTE Mobile Networks RFCs & Standards

Looking inside the MMS Exchange (With call flow and PCAP)

A look at Multimedia Messaging (MMS) in 3GPP Networks and how it actually works.

EPC LTE Mobile Networks Python RFCs & Standards SDM Software

Telephony binary-coded decimal (TBCD) in Python with Examples

Chances are if you’re reading this, you’re trying to work out what Telephony Binary-Coded Decimal encoding is. I got you. Again I found myself staring at encoding trying to guess how it worked, reading references that looped into other references, in this case I was encoding MSISDN AVPs in Diameter. How to Encode a number […]

5G SA EPC EUTRAN LTE Mobile Networks RFCs & Standards SDM Security SIM Cards

The PLMN Problem for Private LTE / 5G

As the number of Private Networks built on LTE and 5G grow, how will PLMN allocation be managed?

EPC LTE Mobile Networks

How UEs get Time in LTE

How does “Network Time” actually get to the UE?

EPC LTE Mobile Networks SDM

Diameter Agents

A look at the 4 types of Diameter Agent

EPC LTE Mobile Networks RFCs & Standards

SCTP Parameter Tuning

A look at tuning your SCTP parameters to detect failures quickly and reduce dropped packets when they happen.

5G SA EPC IMS / VoLTE LTE Mobile Networks SDM VoIP

IMS Routing with iFCs

Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.