Glossary

Application-to-Person SMS. Messages sent from a software application to a mobile user, such as OTP codes, marketing alerts or appointment reminders. Delivered via SMPP or HTTP API.

Average Call Duration. The mean length of successfully connected calls on a route, measured in seconds. Used alongside ASR for route quality assessment.

Automatic Number Identification. The calling party number transmitted in signalling, used for billing, routing and CLI presentation.

Answer Seizure Ratio. The percentage of call attempts that are successfully answered. A key quality metric for voice routes - higher ASR indicates better route quality.

Call Detail Record. A data record produced by a telephone exchange or switch containing details of a call (origin, destination, duration, timestamps). Used for billing reconciliation and analytics.

Calling Line Identification. The phone number presented to the called party. Can be E.164 international format, national format or alphanumeric.

Calls Per Second. The rate at which a switch or platform can set up new calls. A measure of platform capacity at peak load.

Direct Inward Dialling (DID in North America, DDI in Europe). A telephone number that routes directly to an internal extension or endpoint without going through a receptionist or auto-attendant.

Delivery Receipt. A confirmation message returned by the mobile network indicating whether an SMS was successfully delivered, expired or failed.

Do Not Originate. A list maintained by Ofcom of number ranges that should never appear as CLI on outbound calls. Used to detect spoofed CLIs.

Delegated Proof of Stake. A consensus mechanism where token holders vote for a limited set of validators (delegates) who produce blocks and validate transactions. The VPX Protocol uses DPoS for energy-efficient consensus.

Datagram Transport Layer Security - Secure Real-time Transport Protocol. An encryption standard for voice media streams, used by VPX Voice Connect+ for end-to-end call encryption.

Dual-Tone Multi-Frequency. The tones generated when pressing phone keypad buttons. Used for IVR navigation and in-band signalling. RFC 2833 is the recommended relay method for VoIP.

The ITU-T recommendation defining the international public telecommunication numbering plan. Numbers are formatted as + country code + subscriber number (e.g. +442037698080).

Electronic Money Institution / Payment Institution. FCA-regulated licence categories for entities that issue electronic money or provide payment services in the UK. VoicePro Plus has mapped an FCA EMI licence pathway for proprietary banking services.

In the VPX Protocol, a fixed time window during which block production and reward distribution occur. Validators are evaluated per epoch for uptime and performance.

Embedded SIM. A SIM card soldered into a device at manufacture, reprogrammable over-the-air (OTA). Profiles are downloaded via QR code or API. Governed by GSMA SGP.22 (consumer) and SGP.02 (M2M).

An ITU-T standard for multimedia communication over packet-switched networks. Uses gatekeepers for call control (RAS port 1719, Q.931 port 1720). Legacy but still used by some carriers.

Home Location Register. The central database in a mobile network containing subscriber data. HLR lookups reveal whether a number is active, roaming, ported or disconnected.

International Revenue Share Fraud. A scheme where fraudsters generate artificial traffic to premium-rate or high-cost international numbers, earning revenue splits from the terminating operator. The CFCA estimates global telecom fraud at $39 billion (2023).

Least Cost Routing. Algorithmic selection of the lowest-cost available route for a call or message while meeting quality thresholds. VoicePro Plus uses dynamic QoS-weighted LCR.

Mobile Number Portability. The process allowing subscribers to keep their phone number when switching network operators. MNP lookups confirm which network currently serves a number.

Mobile Virtual Network Operator. A wireless carrier that does not own radio spectrum but purchases wholesale access from an MNO (Mobile Network Operator). VoicePro Mobile launches as a full MVNO on 1 November 2026.

The Office of Communications. The UK government-approved regulatory authority for broadcasting, telecommunications, radio spectrum and postal services. VoicePro Plus is registered under the Communications Act 2003 (RID Code: RFI).

Privacy and Electronic Communications Regulations 2003 (UK). Governs electronic marketing, cookies and telecommunications privacy. Requires consent for marketing SMS and email.

Session Initiation Protocol. The dominant VoIP signalling protocol for initiating, managing and terminating voice sessions. Default port 5060 (UDP/TCP). Recommended for all VoicePro Plus interconnects.

In DPoS blockchains, the penalty mechanism for validators who behave dishonestly or go offline during their assigned block production slot. Slashed stake is typically burned or redistributed.

Short Message Peer-to-Peer. The industry-standard protocol for exchanging SMS between carriers, aggregators and SMSCs. Uses TCP connections on port 2775 (plain) or 2776 (TLS).

Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs. A framework for authenticating caller ID to prevent spoofing and robocalling.

Telephone Preference Service. A UK register of individuals who have opted out of receiving unsolicited sales and marketing calls. Checking TPS is a legal requirement before making live marketing calls.

The blockchain foundation of the VPX Ecosystem. Provides an immutable ledger for routing events, fraud records, quality data and settlement transactions, secured by Mysticeti-class DAG-BFT consensus. In development; mainnet planned Q4 2026.

The native utility token of the VPX Ecosystem. Used for staking, governance voting, node operator rewards, carrier fee discounts and consumer rewards. Fixed supply of 1 billion tokens. References to £0.10 / $0.10 per VPXN in whitepaper documents are illustrative examples for economic modelling purposes only.

A telephone fraud scheme (Japanese for "one ring and cut") where fraudsters make brief calls from premium-rate numbers, hoping victims will call back and incur high charges.