Second part in our MMS series, in this one we look at Mobile Terminated MMS.
Recently I had a strange issue I thought I’d share. Using Kamailio as an Interrogating-CSCF, Kamailio was getting the S-CSCF details from the User-Authorization-Answer’s “Server-Name” (602) AVP. The value was set to: sip:scscf.mnc001.mcc001.3gppnetwork.org:5060 But the I-CSCF was only looking up A-Records for scscf.mnc001.mcc001.3gppnetwork.org, not using DNS-SRV. The problem? The Server-Name I had configured as a […]
A deep dive into Mobile Originated MMS via the MM1 Interface
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.
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.
There’s no such thing as a free lunch, and 5G is the same – services running through a 5G Standalone core need to be billed. In 5G Core Networks, the SMF (Session Management Function) reaches out to the CHF (Charging Function) to perform online charging, via the Nchf_ConvergedCharging Service Based Interface (aka reference point). Like […]
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.
A Bind environment in a Docker container for experimenting and learning ENUM for DNS based Call Routing.
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 tuning your SCTP parameters to detect failures quickly and reduce dropped packets when they happen.
5G introduces Network Slicing, or does it? A look at slicing mechanisms widely used in pre-5G networks.