Asterisk is a software implementation of a telephone private branch exchange (PBX).
The 1100 series IP phones is a series of 6 different desktop IP clients manufactured by Avaya for Unified communications which can operate on the SIP or UNIStim protocols.
Elastix is an unified communications server software that brings together IP PBX, email, IM, faxing and collaboration functionality.
A PBX (Private Branch Exchange) is a system that connects telephone extensions to the Public Switched Telephone Network and provides internal communication for a business.
Sangoma Technologies Corporation (Sangoma) is a provider of hardware and software for voice over IP based in Canada.