Categories
EPC IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM Software

Diameter Routing Agents – Part 5 – AVP Transformations

A look at why we’d want to apply translations to Diameter AVPs inside a Diameter Routing Agent

Categories
EPC IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM

Diameter Routing Agents (Why you need them, and how to build them) – Part 2 – Routing

Diving back into the world of Diameter Routing Agents with a look at the logic that defines how a DRA routes traffic from one place to another.

Categories
EPC IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM

Diameter Routing Agents (Why you need them, and how to build them) – Part 1

An introduction to Diameter Routing Agents, covering what is a DRA is and why you need them in your life / network.

Categories
Mobile Networks RFCs & Standards

MMS Deep Dive – MM1 – Mobile Terminated MMS

Second part in our MMS series, in this one we look at Mobile Terminated MMS.

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IMS / VoLTE Kamailio Mobile Networks RFCs & Standards VoIP

Kamailio I-CSCF – SRV Lookup Behaviour

Recently I had a strange issue I thought I’d share. Using Kamailio as an Interrogating-CSCF, Kamailio was getting the S-CSCF details from the User-Authorization-Answer’s “Server-Name” (602) AVP. The value was set to: sip:scscf.mnc001.mcc001.3gppnetwork.org:5060 But the I-CSCF was only looking up A-Records for scscf.mnc001.mcc001.3gppnetwork.org, not using DNS-SRV. The problem? The Server-Name I had configured as a […]

Categories
Mobile Networks RFCs & Standards

MMS Deep Dive – MM1 – Mobile Originated MMS

A deep dive into Mobile Originated MMS via the MM1 Interface

Categories
Mobile Networks RFCs & Standards

ITU International Point Code Structure

A brief look at International Signaling Point Code numbering and what it all means.

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GSM Mobile Networks RFCs & Standards Software VoIP

Demystifying SS7 & Sigtran – Part 4 – Routing with Point Codes

Getting from Point Code A to Point Code Z.

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Mobile Networks RFCs & Standards VoIP

Demystifying SS7 & Sigtran – Part 3 – SS7 Lab in GNS3

Setting up our GNS3 environment with a bunch of SS7 Nodes

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Mobile Networks RFCs & Standards VoIP

Demystifying SS7 & Sigtran (With Labs!) – Part 2 – Ingredients Needed

Looking at the basic components that make up our SS7 Networks.

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Mobile Networks RFCs & Standards VoIP

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?

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 VoIP

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 VoIP

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 VoIP

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 […]