Telecom & SMS glossary
The vocabulary of phone-number intelligence, explained in plain English: how SMS is routed, billed and secured, what carrier lookups actually return, and how AI agents plug into it all. 25 terms, each with a definition, why it matters, and the SMS-24 tool that puts it to work.
Network & subscriber identity
- What is an HLR lookup? HLR lookup
- What is MNP (mobile number portability)? MNP (Mobile Number Portability)
- HLR vs MNP lookup: what is the difference? HLR vs MNP lookup
- What is an MCC (mobile country code)? MCC (Mobile Country Code)
- What is an MNC (mobile network code)? MNC (Mobile Network Code)
- What is an IMSI? IMSI
- What is roaming? Roaming
Messaging protocols & delivery
- What is SMPP? SMPP
- What is an SMSC? SMSC
- What is a DLR (delivery receipt)? DLR (Delivery Receipt)
- What is A2P SMS? A2P SMS
- What is P2P SMS? P2P SMS
- What is an SMS sender ID? Sender ID
Numbering & encoding
- What is E.164? E.164
- What is GSM-7 encoding? GSM-7 encoding
- What is UCS-2 encoding? UCS-2 encoding
- What is an SMS segment? SMS segment
Authentication & fraud
- What is an OTP (one-time password)? OTP (One-Time Password)
- What is 2FA (two-factor authentication)? 2FA (Two-Factor Authentication)
- What is a SIM farm? SIM farm
- What is SMS pumping (artificially inflated traffic)? SMS pumping (AIT)
Numbers, voice & AI agents
- What is a virtual number? Virtual number
- What is a VoIP number? VoIP number
- What is an AI voice agent? AI voice agent
- What is MCP (Model Context Protocol)? MCP (Model Context Protocol)