Glossary of Terms | Crazytel Help Center

Crazytel uses some uncommon abbreviations and terms. This article aims to cover these terms in a digestible manner.

Term	Definition
SIP Trunk	A SIP Trunk is a virtual phone line that connects a device (your phone) to our server. SIP Trunks use the internet to connect calls (which is where VoIP gets its name).
DID(s)	DID (Direct Inward Dialing) is a common abbreviation for 'phone number'. DIDs are publicly accessible, meaning anyone can call the number.
IPND Database	The Integrated Public Number Database (IPND) is a list of all Australian phone numbers. This database is used by emergency services to locate callers and dispatch assistance.
TCP	Transmission Control Protocol (TCP) is a method used to communicate over the Internet. TCP uses robust error checking and ensures each packet (the data being sent) has been received by the other party.
UDP	User Datagram Protocol (UDP) is a method used to communicate over the Internet. UDP does not offer any error checking and does not confirm packets have been received. UDP is a 'Speed over reliability' approach to internet communications.
TLS	Transport Layer Security (TLS) is a method of encrypting data before sending it over the Internet. As the data is encrypted, only the sender and receiver can read the data.
RTP	Real-time Transport Protocol is a method of sending multimedia over the internet by breaking it into smaller, more manageable packets. RTP helps synchronize media between devices to reduce latency or delays for call audio.
SRTP	Secure Real-time Transport Protocol is an encrypted version of RTP. SRTP renders audio streams unreadable (unlistenable) to any eavesdropping parties.
SSL	The Secure Socket Layer is a method of encrypting data before it is sent over the internet. This is an older version of TLS, using older and weaker encryption algorithms.
IVR	An Interactive Voice Response (Auto attendant) is like an automated receptionist. IVRs present callers with a series of options, allowing the caller to quickly choose the department or destination relevant to their call.
2FA / MFA	2 Factor Authentication (2FA) and Multifactor Authentication (MFA) are methods used to verify a person. These methods add an extra layer of security to accounts and actions, so only authorized people have access.
PBX	A Private Branch Exchange is a locally hosted, or cloud-hosted service that handles phone calls. PBXs allow call routes to be set for inbound and outbound calls.
CLI/CID	Caller Line Identification or Caller Identification is the phone number displayed when making or receiving a call.
QoS	Quality of Service is a metric used to quantify the performance of a service. QoS uses information like latency, packet loss, jitter, and bandwidth to generate this metric.
VLAN	Virtual Local Area Networks is a method used to logically sub-divide existing local networks. VLANs allow different devices to exist on their own networks, allowing administrators control over specific types of devices.
LAN	A Local Area Network is a network of private devices within a limited geographical area. A LAN is not accessible to the Public Internet, though usually has access to the Public Internet.
WLAN	Wireless Local Area Network. See LAN.
WAN	Wide Area Network; a network spanning a large geographical area, connecting multiple LANs.
VPN	A Virtual Private Network is a secure tunnel used to communicate directly to another device over the Internet as though it is on the same LAN.
NAT	Network Address Translation is a method of extending IPV4
SBC	A Session Border Controller is a device that sits at the outer edge of your LAN and provides important functionality to VoIP services, including security and improved call quality.
CDN	A Content Delivery Network is a decentralization method that allows internet content to be accessed faster. CDNs are often used for streaming services to reduce load times.
API	An Application Programming Interface is a service that allows software to communicate. APIs are often used to send data from a customer form to the database operating on the server.
HTTP	HyperText Transfer Protocol; a language used to communicate between web browsers (Chrome, Edge, Safari) and the web server. HTTP is an instruction set on how to display the website, where to load images from, and what buttons do when clicked.
HTTPS	HyperText Transfer Protocol Secure; a TLS-encrypted version of HTTPS. This is considered the industry standard.
VoIP	Voice over Internet Protocol; a method of sending Voice (audio) over the internet to another party.
ISP	Internet Service Provider; the company/telco providing your internet connection service. Telstra, Optus, and Kinetix are all ISPs.
PoE	Power over Ethernet; a method of powering devices using an ethernet cable. Most IP Phones have PoE capabilities.
PSTN	Public Switched Telephone Network; the original Global phone network. Crazytel provides access to the PSTN via VoIP.
POTS	Plain Old Telephone System - See PSTN.
FQDN	Fully Qualified Domain Name; a unique identifier used within DNS. FQDNs contain a human-readable hostname like www.crazytel.com.au
DNS	Domain Name System; an 'address book' for computers, telling them which IP address to load information from when accessing a website. DNS acts as a directory for VoIP call routing; changing DNS servers or providers can resolve issues with registrations.
DHCP	Dynamic Host Configuration Protocol; an automatic method used to give an IPV4 (or IPV6) address to a device. This method minimizes the chances of two devices sharing an IP address.
STUN	Session Transversal Utilities for NAT; a service used to discover a device's public-facing IP address. STUN allows devices to identify their IP address as it appears to webservers or other internet-connected devices.
TURN	Transversal Using Relays around NAT; a service used as an alternative to STUN, allowing devices to connect without knowing each other's public IP address.
ACD	Automatic Call Distribution; a system that automatically routes calls to the most appropriate available agent. Average Call Duration; the average time of calls.
BYOD	Bring Your Own Device.
SDP	Session Description Protocol; information carried within SIP messages. SDP outlines critical information about the session, including Audio/Video, Codec in use, timing information, and network addresses of devices.
ENUM	Telephone Numer Mapping; eNumbering. ENUM uses DNS to map traditional phone numbers to IP addresses.
Concurrent Channel Limit	Concurrent Channel Limit is the maximum number of simultaneous calls that can be active at once. In simpler terms, it’s like having multiple phone lines, so if your limit is ten channels, you can have up to ten different calls going on at the same time.
CIS	A CIS is a Critical Information Summary: it is a document detailing what is included in the product, service or plan, and what is limited or excluded.