Definitions

A2P Messaging: it signifies the process where a software application sends messages or notifications to individuals or end-users.
DID: Direct Inward Dialing also known as DDI in Europe and sometimes referred to as a virtual number is a local telephone number in a selected country or city.
Emergency calling: refers to the ability to make telephone calls to emergency services, such as 911 in the United States, 112 in many European countries, or other designated emergency numbers in various regions.
Geographical Number: is a local number, belonging to a particular area/city of a country.
National number: (nomadic number) is not restricted to a particular city/area within a country.

Note

Please note that National type DID(s) may not be reachable from international sources, due to intermediary carriers on the international call leg or local carriers abroad may choose not to or be unable to route the call, often for billing reasons.
Mobile Number: is a number from mobile numbering plan which differs by country.
Toll-Free number: (Freephone/Free call /800 number) allows callers to reach businesses and/or individuals without being charged for the call.

Note

Toll-Free numbers are fully reachable within the country.
Shared Cost Number: is a number which enables sharing call costs between the caller and the number owner.
Metered number: is a DID number charged per minute.
Capacity: (voice channels) defines the maximum number of simultaneous inbound calls per DID.
Trunk: (mapping / call forwarding) defines the connection between DID and call destination.
CDR: (Call data record) provides detailed information about the call.
CLI: (Calling Line Identification / Caller ID) is a feature that identifies and displays the telephone numbers of incoming calls made to a particular line.
SLA: (Service Level Agreement ) is a contract between DIDWW and the customer, which stipulates and commits DIDWW to a certain level of service.
PSTN: (Public Switched Telephone Network) refers to a phone line (fixed or mobile phone).
P2P Messaging: stands for “Person-to-Person Short Message Service.” It refers to the exchange of SMS between individuals.
SAP: (Services Ageing Pool) refers to DID numbers which are expired/removed and no longer active, but can be restored to customer’s account.
NRC: (Non-Recurring Cost ) refers to one-time setup fee applied for service activation.
MRC: (Monthly Recurring Cost) refers to an ongoing monthly fee applied for service renewal.
MMC: (Minimum Monthly Commitment) refers to the amount which needs to be deposited every month to have particular pricing.
API: is Application Programming Interface for a custom integration. An API expresses a software component in terms of its operations, inputs, outputs, and underlying types.
SMS: is a Short Message Service.
FAX: is the telephonic transmission of scanned-in printed material (text or images), usually to a telephone number associated with a printer or other output device.
LNP: means local number portability.
Payment: is a transaction made by Credit Card, Wire Transfer or PayPal.
Order: is a purchase or renewal of any service.
Prepaid balance: is a certain amount of money on customer’s account.
Threshold amount: identifies a certain amount of money in prepaid balance which triggers automatic refill.
UIFN: (Universal International Freephone Number) is a global toll-free telephone number that allows callers from multiple countries to reach a business or organization without incurring any charges for the call.