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 taking SS7 traffic and putting it onto IP / SIGTRAN links on the MTP2 / Layer 2 level.
This post is one of a series of packet capture analysis challenges designed to test your ability to understand what is going on in a network from packet captures.Download the Packet Capture and see how many of the questions you can answer from the attached packet capture. The answers are at the bottom of this […]
Quirks and gotchas of working with SMS on IMS on iPhones.
Using FreeSWITCH as an IMS Application Server
A brief look at International Signaling Point Code numbering and what it all means.
Getting from Point Code A to Point Code Z.
Setting up our GNS3 environment with a bunch of SS7 Nodes
Looking at the basic components that make up our SS7 Networks.
Taking a look at the basics of the SS7 Protocol Stack.
Quick reference guide for the types and capacities of Huawei BBU 3900 Series cards
A look at how Dedicated Bearers get established for VoLTE.
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.
A look at how characters are encoded in an SMS.
How to backup and restore Open5Gs config between servers
How GTP is extended in 5G Core Networks to support extra QoS functionality like Reflective QoS and Delay Indicators
Another deep dive into deceptively simple seeming functions to do with SMS.
5GC includes native support for framed-routing.
A great new feature of #5G Core Networks is Reflective QoS – Where QoS of the traffic coming to a UE is reflected on the QoS coming out.