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.
The Anti-Digit Dialing League
The strange history and triumphs of a group formed to protest the removal of letters from the dialing plan.
Docker & BIND as an ENUM Playground
A Bind environment in a Docker container for experimenting and learning ENUM for DNS based Call Routing.
ENUM – DNS based Call Routing
Using DNS to resolve E.164 phone numbers to routable SIP URIs
Looking inside the MMS Exchange (With call flow and PCAP)
A look at Multimedia Messaging (MMS) in 3GPP Networks and how it actually works.
Telephony binary-coded decimal (TBCD) in Python with Examples
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 […]
The PLMN Problem for Private LTE / 5G
As the number of Private Networks built on LTE and 5G grow, how will PLMN allocation be managed?
SCTP Parameter Tuning
A look at tuning your SCTP parameters to detect failures quickly and reduce dropped packets when they happen.
Australia’s fake Phone Numbers
Numbers that will never connect, reserved for use in TV/Movies & Books.
IMS Routing with iFCs
Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.
Pre-5G Network Slicing
5G introduces Network Slicing, or does it? A look at slicing mechanisms widely used in pre-5G networks.