The Packet Gateway’s purpose in the EPC.
Basic processes and functions of the LTE EPC Serving Gateway (S-GW).
Assigning static IPs to UEs in Open5GS
A look at PFCP for the Sx and N4 Interfaces
Using Wireshark to filter S1 messaging to find signalling from a specific subscriber,
List of Open Source Evolved Packet Core implementations
What’s the deal with Tunnel Endpoint Identifiers and what do they do?
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) […]
Functionality of eNB MME selection based on Relative Capacity IE
Using the new functionality in Open5Gs to select S-GW based on TAC or eNB ID.
Why the BaiCells PLMN changes?
A look into the signalling messages between Network elements in an Evolved Packet Core exchanged during the Attach Procedure
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.
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. […]
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 […]
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 […]
Connecting an external / 3rd party HSS to Open5GS
Sending SMS over LTE using OsmoMSC and OsmoHLR and the SGs interface for SMSoS
Looking into the SGi interface for Circuit Switched Fallback in LTE to use GSM/UMTS networks for Calls & SMS
My first Pull / Merge in the Kamailio project was to fix the IMS P-CSCF config