Categories
EPC EUTRAN IMS / VoLTE LTE Mobile Networks

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

To support Dedicated Bearers we first have to have a way of profiling the traffic, to classify the traffic as being the type we want to provide the Dedicated Bearer for. The first step involves a request from an Application Function (AF) to the PCRF via the Rx interface. The most common type of AF […]

Categories
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.

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 LTE Mobile Networks SDM

Diameter Agents

A look at the 4 types of Diameter Agent

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 IMS / VoLTE LTE Mobile Networks SDM Voice over IP

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.

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

Categories
EPC Kamailio LTE Mobile Networks SDM Software

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, […]

Categories
EPC LTE RFCs & Standards

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

Peculiar padding problem perplexes poor programmer.

Categories
EPC LTE Mobile Networks Python

PyHSS Update – SCTP Support

Info on PyHSS new support for SCTP as well as TCP.

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
5G SA LTE Mobile Networks Python Security Software

PyHSS New Features

Thanks to some recent developments, PyHSS has had a major overhaul recently, and is getting better than ever, Some features that are almost ready for public release are: Config File Instead of having everything defined all over the place a single YAML config file is used to define how the HSS should function. SCTP Support […]

Categories
EPC LTE SDM

Diameter Dispatches: S6a Authentication Information Request / Answer

This is part of a series of posts focusing on common Diameter request pairs, looking at what’s inside and what they do. The Authentication Information Request (AIR) and Authentication Information Answer (AIA) are one of the first steps in authenticating a subscriber, and a very common Diameter transaction. The Process The Authentication Information Request (AIR) […]

Categories
EUTRAN LTE Mobile Networks RFCs & Standards Software

Diameter Dispatches – 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 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 IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM 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
EPC IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM Voice over IP

Diameter and SIP: User-Authorization-Request/Answer

The Diameter User-Authorization-Request and User-Authorization-Answer commands are used as the first line of authorization of a user and to determine which Serving-CSCF to forward a request to.

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

Diameter and SIP: Server-Assignment-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 Server-Assignment-Request/Answer commands are used so a SIP Server can indicate to a Diameter server that it is serving a subscriber and pull the profile information of the subscriber. […]

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

Diameter and SIP: Location-Info-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 Location-Information-Request/Answer commands are used so a SIP Server query a Diameter to find which P-CSCF a Subscriber is being served by Basics: The RFC’s definition is actually pretty […]