Unstructured Supplementary Service Data or “USSD” is the stack used in Cellular Networks to offer interactive text based menus and systems to Subscribers. If you remember topping up your mobile phone credit via a text menu on your flip phone, there’s a good chance that was USSD*. For a period, USSD Services provided Sporting Scores, […]
A look at attack vectors the NRF opens up in #5G Core networks, and the mitigations recommended by 3GPP.
Looking for Love in the 5G Core?
Let’s look at our matchmaker – The Network Repository Function in 5G Core.
How to backup and restore Open5Gs config between servers
A look at Centralized vs DeCentralized Online Charging with the aid of sugar.
A look at the Equipment Identity Register in 5G Core
A glimpse into the complexities of prepaid billing (Online Charging) Diameter based networks.
A look at how the HSS can update the profile of an already in-use subscription using Insert Subscriber Data Request/Response.
How turning mobile data off, doesn’t, in LTE and 5G.
Using DNS to resolve E.164 phone numbers to routable SIP URIs
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 […]
As the number of Private Networks built on LTE and 5G grow, how will PLMN allocation be managed?
A look at the 4 types of Diameter Agent
Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.
Getting to know IPfilterRules and the Flow-Description AVP
New database time to support slicing and a migration path for existing users.
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, […]
Using Wireshark to sniff communication between your computer and Smart Card / SIM Card
Sending commands/APDUs to a real life Smart Card.
A look at the Confidentiality Algorithms used in 3GPP Networks, MILENAGE, XOR & Comp128