Glossary

CLI Calling Line Identity. The feature of showing the calling party’s number on the receiving party’s handset.
DTMF Dual Tone Multi Frequency. Signal created when pressing touch keys on a handset during a phone call.
Media Codec Definition of how the media, in this case audio, is compressed.
PSTN Public Switched Telephone Network. The aggregate of all fixed and mobile networks that allows any telephone in the world to communicate with any other telephone.
RTP Real-time Transport Protocol. Standardized packet format for delivering media such as voice and video over the internet.
SIP Session Initiation Protocol. Industry standard protocol for controlling media communication sessions such as voice and video calls over the internet.