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
5G SA EPC Linux LTE Mobile Networks

Open5GS without NAT

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

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

How UEs get Time in LTE

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

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
5G SA EPC LTE Mobile Networks SDM Software

Open5Gs Database Schema Change

New database time to support slicing and a migration path for existing users.

Categories
5G SA EPC LTE Mobile Networks

MTU in LTE & 5G Transmission Networks – Part 1

A look at MTU and its role in LTE and 5G Transmission.

Categories
EPC LTE Mobile Networks

LTE EPC: Packet Gateway (P-GW) Basic Function

The Packet Gateway’s purpose in the EPC.

Categories
EPC LTE Mobile Networks

LTE EPC: Serving Gateway (S-GW) Basic Function

Basic processes and functions of the LTE EPC Serving Gateway (S-GW).

Categories
EPC LTE Mobile Networks

Open5GS EPC: Static IP Addresses for UEs / APNs / Subscribers

Assigning static IPs to UEs in Open5GS

Categories
EPC Mobile Networks SDM

Wireshark Filtering S1AP to find Subscriber Signaling

Using Wireshark to filter S1 messaging to find signalling from a specific subscriber,

Categories
EPC LTE Mobile Networks Software

List of Open Source Evolved Packet Core (EPC) Implementations

List of Open Source Evolved Packet Core implementations

Categories
EPC EUTRAN LTE Mobile Networks

S1AP – Relative Capacity (87) on MME

Functionality of eNB MME selection based on Relative Capacity IE

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 […]

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

Diameter and SIP: Multimedia-Authentication-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 Multimedia-Authentication-Request/Answer commands are used to Authenticate subscribers / UAs using a variety of mechanisms such as straight MD5 and AKAv1-MD5. Basics: When a SIP Server (S-CSCF) receives a […]

Categories
EPC EUTRAN GSM IMS / VoLTE LTE Mobile Networks

Sending SMS in Open5GS LTE Networks using the SGs Interface and OsmoMSC with SMSoS

Sending SMS over LTE using OsmoMSC and OsmoHLR and the SGs interface for SMSoS