A look at how Dedicated Bearers get established for VoLTE.
Category Archives: EPC
Backing up and Restoring Open5GS
How to backup and restore Open5Gs config between servers
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.
Basics of EPC/LTE Online Charging (OCS)
A glimpse into the complexities of prepaid billing (Online Charging) Diameter based networks.
Open5GS without NAT
Setting up Open5Gs without a NAT requirement, and the routing required to do so.
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.
PS Data Off
How turning mobile data off, doesn’t, in LTE and 5G.
Docker & BIND as an ENUM Playground
A Bind environment in a Docker container for experimenting and learning ENUM for DNS based Call Routing.
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 … Continue reading Telephony binary-coded decimal (TBCD) in Python with Examples
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?
How UEs get Time in LTE
How does “Network Time” actually get to the UE?
Diameter Agents
A look at the 4 types of Diameter Agent
SCTP Parameter Tuning
A look at tuning your SCTP parameters to detect failures quickly and reduce dropped packets when they happen.
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.
Pre-5G Network Slicing
5G introduces Network Slicing, or does it? A look at slicing mechanisms widely used in pre-5G networks.
Diameter Droplets – The Flow-Description AVP and IPFilterRules
Getting to know IPfilterRules and the Flow-Description AVP
The Surprisingly Complicated world of MO SMS in IMS/VoLTE
Short messaging can be anything but simple…
Open5Gs Database Schema Change
New database time to support slicing and a migration path for existing users.
A very unstable Diameter Routing Agent (DRA) with Kamailio
I’d been trying for some time to get Kamailio acting as a Diameter Routing Agent with mixed success, and eventually got it working, after a few changes to the codebase of the ims_diameter_server module. It is rather unstable, in that if it fails to dispatch to a Diameter peer, the whole thing comes crumbling down, … Continue reading A very unstable Diameter Routing Agent (DRA) with Kamailio
PyHSS Update – YAML Config Files
Introducing YAML based config files for defining how PyHSS should be setup
Random Posts on EPC
LTE (4G) – USIM Basics
SCTP Multihoming
The Surprisingly Complicated world of MO SMS in IMS/VoLTE
Demystifying SS7 & Sigtran (With Labs!) – Part 2 – Ingredients Needed
DTMF over IP – SIP INFO, Inband & RTP Events
NBN FTTN Nodes in Disguise
RFC2833 – RTP Events
Kamailio Bytes – Permissions Module
SIM / Smart Card Deep Dive – Part 2 – Meet & Greet
