Telecom Systems
SS7 and SIGTRAN, SIP, SMPP, USSD, SMSC, Asterisk and core telco architecture.
Telecom Systems articles
Your First Asterisk Dialplan
Asterisk's dialplan is a state machine in a text file. Here's a real extensions.conf — internal extensions, voicemail, an IVR, and an outbound trunk — explained line by line.
October 24, 2026Core Telco Architecture: 2G to 5G in One Read
MSC, SGSN, GGSN, MME, SGW, PGW, AMF, SMF, UPF — decades of telco core acronyms, mapped across generations so the lineage is clear.
October 24, 2026SMSC Basics for Sysadmins
The SMSC is the store-and-forward hub for text messages. Here's the message paths (MO, MT, AO, AT), how retries work, and a Kannel config to get started.
October 24, 2026SIP Trunk Basics for Sysadmins
A sysadmin's view of SIP trunking — signalling vs media, the ports involved, and why one-way audio is almost always NAT.
October 24, 2026Diameter Routing Agents in Depth
A Diameter Routing Agent is the STP of the LTE/IMS world — it routes messages by realm and application so nodes don't need full-mesh peering. Here's the agent types and routing.
September 8, 2026