A repository of the technical terms and jargon intrepid Twilio developers may encounter on their building journey.
Alphanumeric Sender ID allows you to set your company name or brand as the Sender ID when sending one-way SMS messages to supported countries. Alphanumeric Sender IDs may be up to 11 characters. Accepted characters include both upper- and lower-case ASCII letters, the digits 0 through 9, and space: A-Z, a-z, 0-9. They may not be only numbers.
An Application Programming Interface (API) is provided by a service or program so that others may use the features and functions of the system. APIs are like a contract that describes how a consumer will make requests of the system, and what they will receive in return.
A2P, or Application-to-Person, messaging is one-way SMS to which recipients are not expected to reply. When you send a text message to vote for your favorite singer on the TV talent show, you are using A2P messaing. Software applications use an API to send an receive texts.
An Area Code Overlay is an area code that covers the same area as another area code. In North America, each area code has a potential capacity of around 8 Million unique phone numbers (7,919,900 to be exact). Many area codes have exhausted all possible phone numbers, so one or more area codes are added to accommodate.
C# (pronounced "see sharp") is a computer programming language created by Microsoft for use on the .NET platform. It is an object oriented programming (OOP) language and is statically typed. Its name comes from the C language, from which it inherits a similar syntax.
Call Tracking is a software-based performance marketing technique that generates and assigns a unique phone number to a specific advertisement or marketing campaign. Call Tracking systems then follow and analyze leads through that phone number “channel” to understand the channel’s true effectiveness and ROI or receive a commission for driving that lead.
Call Whisper, also commonly referred to as Call Screening, involves playing a message to the callee while the caller continues to hear ringing. It can provide additional information such as the source or purpose of the call to the callee before the call begins and even allow the callee to accept or reject the call based on that information.
Direct Inward Dialing (DID) is a telephone service that allows a phone number to ring through directly to a specific phone at a business instead of going to a menu or a queue and needing to dial an extension. A phone number that is used like this is often called a "DID" (and multiple numbers are called "DIDs”).
DTMF stands for Dual-Tone Multi-Frequency signaling. They're the tones that you hear when you press the numbers on your phone's keypad. Back in the day, before touch tone phones, folks had to use a rotary to input numbers. Then Bell Systems came along and saved folks from running their fingers around in circles. Their system was trademarked as Touch-Tone.
Today, DTMF tones are used to initiate a phone call, and to punch in input in IVRs.
E.164 is the international telephone numbering plan that ensures each device on the PSTN has globally unique number. This is what allows phone calls and text messages can be correctly routed to individual phones in different countries. E.164 numbers are formatted [+] [country code] [subscriber number including area code] and can have a maximum of fifteen digits.
GPRS, or General Packet Radio Service, is a best-effort packet-switching communications protocol for cellular networks.
GPRS was one of the first widely used data transfer protocols on cellular networks, first standardized in 3GPP's Release 97 in the first quarter of 1998. Commercial cellular networks began to support GPRS in 2000.
GSM-7 is a character encoding standard which packs the most commonly used letters and symbols in many languages into 7 bits each for usage on GSM networks. As SMS messages are transmitted 140 8-bit octets at a time, GSM-7 encoded SMS messages can carry up to 160 characters.
Interactive Voice Response (IVR) is an automated telephony system that interacts with human callers through the use of voice and touch-tone keypad selections (DTMF tones). It’s also commonly known as a phone tree.
Jitter is the variation in periodicity of a signal or periodic event from its target or true frequency. In telecommunications, jitter further refers to the variation in latency of packets carrying voice or video data over a communications channel.
Latency is the time delay between the initiation of an event and its perception by some observer. In networking and telecommunications, latency is the time between a sender causing a change in a system's state and its reception by an observer. Network latency is often informally used interchangeably with lag.
Live chat is a type of online chat distinguished by its simplicity and user accessibility. Live chat appears in a web browser or in mobile applications, usually via a small pop-up modal through which the visitor can exchange text messages with a chat operator in real time.
A long code number is a standard phone number used to send and receive voice calls and SMS messages. Phone numbers are typically called “long codes” (10-digit numbers in many countries) when comparing them with SMS short codes (5-6 digit numbers).
Masked calling is a technique used in ecommerce to protect buyers' and sellers' personal phone numbers private. It uses a short-lived phone number for each party, allowing them to communicate seamlessly during a specified time period. After the time period has expired, the numbers are recycled and reassigned to other parties on the platform, which helps keep transactions from happening outside the platform.
A Mean Opinion Score (MOS) is a numerical measure of the human-judged overall quality of an event or experience. In telecommunications, a Mean Opinion Score is a ranking of the quality of voice and video sessions.
Most often judged on a scale of 1 (bad) to 5 (excellent), Mean Opinion Scores are the average of a number of other human-scored individual parameters. Although originally Mean Opinion Scores were derived from surveys of expert observers, today a MOS is often produced by an Objective Measurement Method approximating a human ranking.
MMS, short for Multimedia Messaging Service, is a standard way to send multimedia such as pictures, videos, and other attachments over text messaging channels.
Network Address Translation (NAT) is the modification of in-transit network packets to map one IP address space to another. It is most commonly used in IP Masquerading, where a large private IP network shares a relatively small number of publicly facing IP addresses behind a router or gateway.
P2P stands for Person-to-Person messaging. In simple terms, this is when two or more people communicate over text messaging. For example, when you send a text message from your phone to another person's phone, that's P2P. This can also include traffic that goes through an API to connect two people.
Packet loss refers to the failure of packets to reach their destination on a network. Packet loss is most often a consequence of network congestion and usually caused by network equipment dropping, ignoring, misdelivering, or discarding packets.
PBX, short for Private Branch Exchange, is a phone system in an enterprise that manages incoming and outgoing phone calls as well as an organization’s internal communications.
The PSTN (Publicly Switched Telephone Network) is the network that carries your voice calls when you call from a landline or cell phone. It refers to the worldwide network of voice-carrying telephone infrastructure, including privately-owned and government-owned infrastrucure.
A push notification (also known as a server push notification) is the delivery of information to a computing device from an application server where the request for the transaction is initiated by the server rather than by an explicit request from the client. While 'push notification' is most often used to refer to notifications on mobile devices, web applications also leverage this technology.
A REST API allows software programs to expose functionality and data to other programs over the Internet in a consistent format. APIs are considered RESTful if the means of accessing the API provider's functionality adhere to the architectural style of REST.
A software development kit, or SDK, is a downloadable software package that contains the tools you need to build on a platform.
Serverless architecture (also known as serverless computing or function as a service, FaaS) is a software design pattern where applications are hosted by a third-party service, eliminating the need for server software and hardware management by the developer. Applications are broken up into individual functions that can be invoked and scaled individually.
Session Initiation Protocol (SIP) is a signalling protocol for initiating, terminating, and modifying user sessions over an IP network. Most commonly, SIP is used for Voice Over IP (VoIP) services, but is also often used for other communications sessions such as video calls and instant messaging sessions.
A short code is a special 5 or 6 digit telephone number that's shorter than a full phone number. Short codes are used to send and receive SMS and MMS messages to and from mobile phones. Twilio currently offers short codes in the US, Canada, and the UK.
A SIP trunk is a virtual version of an analog phone line, eliminating the physical connection to a phone company. Using SIP trunks, a SIP provider can connect multiple channels to your PBX, allowing you to instantly provision global voice connectivity for your Voice over IP (VoIP) infrastructure.
SMS stands for Short Message Service and is another name for a text message. SMS is the only standard with the ability to send text messages to (almost) any mobile phone over telecommunications networks.
The character limit for a single SMS message is 160 characters, however most modern phones and networks support concatenation and segment and rebuild messages up to 1600 characters. Messages not using GSM-7 encoding are limited to 67 characters.
An SMS Gateway enables a computer to send and receive SMS text messages to and from a SMS capable device over the global telecomunications network (normally to a mobile phone). The SMS Gateway translates the message sent, and makes it compatible for delivery over the network to be able to reach the recipient.
An SMS tracker is software that uncovers detailed information about the delivery and content of text and picture messages. It allows anyone to analyze an individual message or group of messages to see delivery patterns, encoding details, and error conditions.
The TCPA (Telephone Consumer Protection Act) is a federal statute enacted in 1991 designed to safeguard consumer privacy. This legislation restricts telemarketing communications via voice calls, SMS texts, and fax.
TwiML, or the Twilio Markup Language, is an XML based language which instructs Twilio on how to handle various events such as incoming and outgoing calls, SMS messages and MMS messages. When building a Twilio application you will use TwiML when communicating your desired actions to Twilio.
Two factor authentication (commonly abbreviated 2FA) adds an extra layer of security to your user’s account login by requiring two forms of authentication: something your user knows and something they have.
UCS-2 is an character encoding standard in which characters are represented by a fixed-length 16 bits (2 bytes). It is used as a fallback on many GSM networks when a message cannot be encoded using GSM-7 or when a language requires more than 128 characters to be rendered.
A virtual phone number is a standard telephone number that is not locked down to a specific phone. A virtual number can route a voice call or text message to any phone or workflow. With virtual numbers powered by an API, complex software workflows can be built that are triggered by calls and texts.
Virtual SMS enables you to send and recieve SMS text messages over the internet without having to use a physical phone. This is especially useful when you want to use software to communicate with telephone networks that would be impossible on a physical phone, e.g. Uber notifying a customer that their car is outside or to have local phone numbers in different countries.
A voice API is a tool for software developers to make and receive phone calls with a simple, easy to understand API. Behind the scenes, a voice API bridges the Public Switched Telephone Network (PSTN) and applications connected to the internet. By using a voice API, software developers can program voice calling into their applications without specialized telecommunications knowledge and hardware.
Voice Proxy is also known as Masked Calling. It refers to the technique used to protect users' private information by providing an intermediary number so that neither party can see the other's true phone number for voice calls or SMS.
Voice Over Internet Protocol (VoIP) is a category of hardware and software that enables voice calls to be made and received over the internet.
Webhooks are user-defined HTTP callbacks. They are triggered by some event in a web application and can facilitate integrating different applications or third-party APIs, like Twilio.
Web Real-Time Communication (WebRTC) is a collection of communications protocols and APIs originally developed by Google that enable real-time voice and video communication over peer-to-peer connections.
A WebSocket is a persistent bi-directional communication channel between a client (e.g. a browser) and a backend service. In contrast with HTTP request/response connections, websockets can transport any number of protocols and provide server-to-client message delivery without polling.