Glossary of Terms

Term	Explanation
API	An Application Program interface (API) is a set of routines, protocols, and tools for building software applications. The API specifies how software components should interact and APIs are used when programming graphical user interface (GUI) components.
APN	An Access Point Name (APN) is the name of a gateway between a GSM, GPRS, 3G or 4G mobile network and another computer network, frequently the public Internet.
CSV	A CSV is a comma separated values file which allows data to be saved in a table structured format. Traditionally a CSV file takes the form of a text file containing information separated by commas, hence the name.
GPRS	General Packet Radio Service (GPRS) is a packet oriented mobile data service on the 2G and 3G cellular communication system's global system for mobile communications (GSM)
HLR	The Home Location Register (HLR) is the main database of permanent subscriber information for a mobile network.
IMSI	An International Mobile Subscriber Identity (IMSI) is a unique number, usually fifteen digits, associated with Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS) network mobile phone users. The IMSI is a unique number identifying a GSM subscriber.
MCC	Mobile Country Code
MNC	A Mobile Network Code (MNC) is used in combination with a mobile country code (MCC) (also known as a "MCC / MNC tuple") to uniquely identify a mobile phone operator/carrier using the GSM/LTE, CDMA, iDEN, TETRA and UMTS public land mobile networks and some satellite mobile networks.
MO	Mobile Originated.
MSISDN	The Mobile Subscriber Integrated Services Digital Network-Number(MSISDN) Is a number uniquely identifying a subscription in a GSM or a UMTS mobile network. Simply put, it is the telephone number to the SIM card in a mobile/cellular phone.
MT	Mobile Terminated
NAT	Network Address Translation (NAT) is a method of remapping one IP address space into another by modifying network address information in Internet Protocol (IP) datagram packet headers while they are in transit across a traffic routing device.
NDC	For geographic telephone numbers, the National Destination Code (NDC) digits are the geographically significant leading digits of the NSN, but shown without the initial 0 trunk code. The NDC digits can be omitted when making a local call within the same area. The NDC is, in effect, another name for "area code", previously called STD (Subscriber Trunk Dialing) code.
NPI	The Numbering Plan Indicator (NPI) describes which numbering plan will be used for the global title. The numbering plan chosen will aid the routing system in determining the correct network system to direct the message.
TADIG	TADIG code is a number uniquely identifying network operators in a GSM mobile network. The acronym TADIG expands to "Transferred Account Data Interchange Group". According to the GSM specification, the codes are used as "primary identifiers within file contents and file names" in multiple file formats defined by the GSMA. Network operators are required to register new codes and limit themselves to using code already registered with the GSMA.TADIG codes are generally used by bilateral agreement for the purposes of billing roaming telephone calls.
UMTS	The Universal Mobile Telecommunications Service (UMTS) is a third-generation (3G) broadband, packet-based transmission of text, digitized voice, video, and multimedia at data rates up to 2 megabits per second (Mbps).. UMTS is based on the Global System for Mobile (GSM) communication standard.
VPN	A virtual private network (VPN) is a network that is constructed using public wires — usually the Internet — to connect remote users or regional offices to a company's private network.