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Mobile Networks RFCs & Standards Voice over IP

Demystifying SS7 & Sigtran Networks (With Labs!) – Part 1 – Intro

Taking a look at the basics of the SS7 Protocol Stack.

Categories
5G SA Mobile Networks RFCs & Standards SDM Security

Some thoughts on NRF Security in 5G Core

A look at attack vectors the NRF opens up in #5G Core networks, and the mitigations recommended by 3GPP.

Categories
5G SA Mobile Networks RFCs & Standards SDM

If you like Pina Coladas, and service the control plane – Intro to NRF in 5GC

Looking for Love in the 5G Core?

Are you a lonely UDM from MCC 001 MNC 001, just looking for a connection?

PLMN 901/70, NRF, seeks same.

Let’s look at our matchmaker – The Network Repository Function in 5G Core.

Categories
5G SA Mobile Networks RFCs & Standards

5G Online Charging with the Nchf_ConvergedCharging SBI

There’s no such thing as a free lunch, and 5G is the same – services running through a 5G Standalone core need to be billed. In 5G Core Networks, the SMF (Session Management Function) reaches out to the CHF (Charging Function) to perform online charging, via the Nchf_ConvergedCharging Service Based Interface (aka reference point). Like […]

Categories
EPC LTE Mobile Networks RFCs & Standards SDM Voice over IP

Basics of EPC/LTE Online Charging (OCS)

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

Categories
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.

Categories
EPC Mobile Networks RFCs & Standards Voice over IP

Docker & BIND as an ENUM Playground

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

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IMS / VoLTE Mobile Networks RFCs & Standards SDM Voice over IP

ENUM – DNS based Call Routing

Using DNS to resolve E.164 phone numbers to routable SIP URIs

Categories
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.

Categories
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 […]

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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?

Categories
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.

Categories
5G SA EPC EUTRAN GSM LTE Mobile Networks RFCs & Standards

Pre-5G Network Slicing

5G introduces Network Slicing, or does it? A look at slicing mechanisms widely used in pre-5G networks.

Categories
EPC LTE Mobile Networks RFCs & Standards SDM

Diameter Droplets – The Flow-Description AVP and IPFilterRules

Getting to know IPfilterRules and the Flow-Description AVP

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EPC GSM IMS / VoLTE LTE Mobile Networks RFCs & Standards

The Surprisingly Complicated world of MO SMS in IMS/VoLTE

Short messaging can be anything but simple…

Categories
5G SA Mobile Networks RFCs & Standards

5Gethernet? – Transporting Non-IP data in 5G

A look at non-IP transport for 5G including Ethernet.

Categories
Notes RFCs & Standards Software

Diff + Wireshark

Comparing packet contents with Wireshark and a diff utility

Categories
EPC LTE RFCs & Standards

MSISDN Encoding in Diameter AVPs – Brought to you by the letter F

Peculiar padding problem perplexes poor programmer.

Categories
5G SA EPC EUTRAN GSM LTE Mobile Networks RFCs & Standards Security

And the call was coming from… INSIDE THE HOUSE. A look at finding UE Locations in LTE

How to find a subscriber location within the network.

Categories
Mobile Networks Python RFCs & Standards Software

Dr StrangeEncoding or: How I learned to stop worrying and love ASN.1

Australia is a strange country; As a kid I was scared of dogs, and in response, our family got a dog. This year started off with adventures working with ASN.1 encoded data, and after a week of banging my head against the table, I was scared of ASN.1 encoding. But now I love dogs, and […]