KNOWLEDGE BASE
The communications glossary
Plain-English explainers on how modern phone systems actually work — from a single SIP packet to an air-gapped, sovereign communications platform. Start anywhere; each one points you to what comes next.
VoIP & telephony foundations
Start here. The building blocks every phone system is made of — what they are, and why they decide how secure and how sovereign your communications can be.
VoIP →
VoIP (Voice over Internet Protocol) carries voice calls as digital packets over an IP network instead of the traditional circuit-switched telephone line. …
SIP (Session Initiation Protocol) →
SIP (Session Initiation Protocol) is the signalling language IP phones use to start, manage and end calls. It doesn't carry your voice …
SIP trunking →
A SIP trunk is a virtual connection between your IP phone system and a telephony provider (ITSP) that gives you access to …
IP PBX →
An IP PBX (IP Private Branch Exchange) is the server software that runs a business phone system: registering phones, routing calls, and …
On-premise & sovereign communications
Where your calls live, and who can reach the data they create. The difference between renting your phone system and owning it.
On-premise vs cloud PBX →
A cloud (hosted) PBX runs on a provider's infrastructure and is rented per user; an on-premise PBX runs on servers you own …
Self-hosted PBX →
A self-hosted PBX is a phone system you install and run on servers you own — on-premise or in your own private …
Air-gapped communications →
Air-gapped communications run on an isolated network that has no link to the public internet. A truly air-gapped phone system can be …
Data sovereignty →
Data sovereignty is the principle that data is governed by the laws of the jurisdiction where it resides, and should stay under …
Communications security
A phone system is an attack surface and a billing liability. These are the threats — and the controls that shut them down.
Toll fraud →
Toll fraud is the unauthorised use of a phone system to place calls — usually to international or premium-rate numbers — at …
SRTP →
SRTP (Secure Real-time Transport Protocol) encrypts the media — the actual voice and video — of a call, so it can't be …
TLS for SIP →
TLS for SIP (SIP over TLS, usually on port 5061) encrypts the signalling of a call so credentials, phone numbers and call …
Unified communications
Voice, video and messaging as one system. The features that turn a dial tone into a workplace.